Not only that but it's got noise too. Any one individual isn't going to have exactly the same traits as average, and often individuals might have quite different traits.
Nice summary of my diatribe. It's a meaningful distinction without a meaningful definition. What second, minute, hour or day does an adolescent become an adult? You know it when you see it, but you cannot pinpoint when it occurs. Perhaps one day we'll have the resolution needed to define species, but not today.
Exactly... however, not only do we humans prefer to label things, but we have become accustomed to seeing them that way. And, even beyond that, it could be claimed to be an actual feature of how our thoughts are structured. And, likewise, when we see pictures of primates or other species in textbooks, those also virtually ALWAYS have a specific label... (And just try to find a nature show on TV that neglects to NAME every single animal they show.) We virtually never see one labeled as "halfway between this and that species"... In fact, when we discover one, almost the first thing we do is to rush to CREATE a specific label to go with our new discovery. It would be more accurate to simply use dates... and technical details... but we humans find that to be so cumbersome as to be unworkable... But, however useful this is, it does "program" us to see things in distinct categories or cubbyholes. I work in the audio and home theater industry... and every day I see this issue... in reverse. Many people are virtually incapable of understanding how a series of digital "numbers" can accurately represent an analog signal. They are apparently simply unable to see the two as different representations of exactly the same thing.
I don't understand how you can put so much effort into explaining and articulating this so well, and yet some people still take away "evolution is stoopid". Well done, as always
@@MegaeffinGarchomp17 People tend to value personal and social comfort, we don't really gain benefits out of "the truth". If you live in a group, which sees evolution as a threat, or have a world view, where evolution doesn't fit, it is much better for this person to deny evolution, especially if it has zero impact on their daily live. Truth is only valuable, if you face environmental issues, which you need to solve and need to understand the issue first. However, that evolution is not a day to day problem for most people, so it is cheap to deny. Of course, there is a long term cost, but people are very bad in taking long term problems serious (all of us). In that sense, it is just logical to deny evolution (for them). At least, that is how I rationalize it (haven't found anyone to talk to personally, who denies evolution)
This reminds me of the "coastline problem " in geography where trying to map out the coast of a country is actually rather problematic when you get closer to smaller units of measure.
The name of the mathematics is fractal length of a coast line. 0 for a dot, 1 for a line, 2 for a square, in that measurement many coastlines are ~1.5. The Norwegian coastline has highest dimension.
Fuzzy math/logic is part of the real world. That is another example of the lack of a binary answer. Erica is acting as if reality is binary. Its fuzzy. Even at the lowest level of physics.
The species problem also seems to be somewhat fractal in nature. Lots of self similarities AND differences depending on which path you take. However, on the topic of definitions, even if you can't come up with a perfect all-encompassing definition of species it's not an entirely useless concept. You just need to remember the lines are fuzzy and don't always apply.
@@ethelredhardrede1838 "Erica is acting as if reality is binary. Its fuzzy." - I think you need to re-watch. She just explained that biology is not binary. "Even at the lowest level of physics" - totally unrelated.
@@freddan6fly I had no problem with watching it. She understood that it is not binary but is insisting that species must be defined as being binary or they don't exist. That is where her error lies. Mayer's definition is more than adequate for sexualy reproducing in more than 90 percent of them at any giving time. It's not a merely human definition, it's a description of sexualy reproducing organism actually function. The purpose of the term is to communicate, not to force a concept on reality. Species exist in real life, that is why the term is useful to communicate. That it's not binary as Erica is insisting it must to be real does not make any less useful to communicate. What does she want to replace it with? An essay each time that a single word will do?
Defining "species" is troublesome because it's a _static_ concept applied to a _dynamic_ process. That's easy enough to remember, thank you! In one of his more recent books (I forget which) Dawkins makes the statement that every organism has been and always will be the same species as its parents, a statement that, taken out of concept seems to contradict evolution, especially for people who don't understand evolution. But knowing it as a gradual and dynamic process, with complications such as hybridization, that makes sense.
It's the problem of the heap. A grain of sand is clearly not a heap of sand. But if you add a grain at a time, at some point you will have a heap. But there's no clear line when it becomes a heap.
The basic problem here is, you start with two things considered equal, but very slowly there is an increment in diferences, so you need to decide when those two things can not be longer classified as 'equal' but 'different'. I still think that is possible a better definition of 'species', but involving mathematical modelling and measuring the amount of change over time. A species could be a group of organisms that stays within less than x amount of change involving at least y generations. The 'procreating with your own kin' thing should be considered a factor that helps in the creation of species instead of a defining factor of the definition.
Always good to remember that so many things in our world are not "real" in the sense that they are manmade concepts in a (desperate) attempt to make sense of the world we live in. They can still be incredibly useful though. Yet I've also come to think that, in a weird way, as long as someone has thought of them, those things are "real". Take a fictional character for example. They can have a profound impact on "real" people and influence these people as much as "real" people do, and yet they themselves are not considered "real". And what is "real" anyway? In the end we humans are just a bunch of complicated chemistry that has developed the emerging property of being hyper self-aware. Being alive and aware is scary and things often get so, so fuzzy. That's why so many people turn to religion and other superstitions, it gives them the reassuring feeling of being able to make absolute sense of the world. The longer I live the more I've come to think that in reality there are very few things about life and the universe one can say with reasonable confidence are absolutely certain...
I agree to some extent, species are real, only they are a fuzzy concept rather than a discrete one, and this is because a species is a dynamic system. A single object that doesn't change with time can be defined uniquely: a cube is a cube... is a cube, and doesn't turn into a sphere or tetragon. A storm, on the other hand, is an identifiable system - you know when you are caught in one and satellites can tell you its size, speed and therefore duration, but it's not isolated from the other weather systems on the planet, which all interact. So I disagree with the simplistic assertion that "species don't exist." They don't exist as unchanging and discrete systems. They do exist as dynamic ones.
Making sense of our world by giving things names and catagories is not so desperate, in fact I would suggest it is a very sencible thing to do. Real is real, thats why there is science and plenty is certain, albeit humans have a history of wild speculation. I think what you are suffering from Sir or Madam is a mid life crisis. Gutsick on the other hand may well be mixing druggies and knowledge to great effect?
@@Leszek.Rzepecki The storm is a good analogy Lasek, but is the cube as good? A physical cube too is really in a state of change, usually a much slower process is at work - depending on the material you build the cube of. Unless of course you were referring to a cube in the conceptual sense. The concept of a cube is not subject to the forces of physics. But can it be said to exist outside the collective consciousness of man? As we have not yet found another animal with such arcane concepts, it must be an open question.
I really appreciate your content Erika. My most recent formal biology class was a 5 credit Bio 101 course in 1981. Videos like this really help me to stay at least somewhat up to date with developments in the field.
@@recreant359 Professor Dave helped me through part of my degree in biology with his vids, and Erica is exceptionally knowledgeable vis a vis primate evolution and biology. Yes books, and peer review are excellent, however, they can be very dry, an d this is where these videos come in useful. To give an introduction to or to explain difficult concepts, so that one has a better understanding of what they are going to read, when they go to read the paper, or book.
As it is often mentioned, there is a lot of parallel with how languages evolved. My mother tongue is French. I speak a romance language, which is the language family to which Italian, Spanish, Portuguese or Romanian belong to. Learning one of these languages require much less effort for me than for someone who would speak Japanese. I went to Cuba a few years ago, and it took me only a few days to learn some basic phrases, which all presented some regular variations with French. After a week I could understand some basic Spanish. Italians or Spaniards who come to France can learn the language in a few months compared to someone whose mother tongue would be Russian or Chinese. When the Latin language started to evolve in different dialects, people could understand each other from valley to valley or river banks to river banks. However, two centuries later, someone from the North of France would have had a hard time to understand someone from the South of Spain. Since, animals are often a genetic continuum, I would think that the only way to differentiate species would be to use a notion of energy. How much energy is required to jump the genetic or geographic differences between animals? For instance, it takes more energy for me to learn Romanian than Italian, since French and Romanian evolved in very different cultural environment. French was heavily influenced by Germanic languages and Romanian by Slavic languages.
Personally, I wouldn't say it's a 1:1 comparison when it comes to linguistic evolution and physiological/genetic change over time. Languages are, like the species concepts mentioned in this video, largely semiotic constructs which help us convey ideas and make sense of the natural world; the selective pressures can differ dramatically. In order for a an animal to "jump" the genetic differences between animals, no amount of energy would allow a kangaroo to reproduce with a dolphin (at least, I don't think so - that would be a sight to behold, though). Geographically speaking, factors like migration can vary widely in terms of time and distance. Likewise, as we must consider a vast array of ecological (and sometimes social) phenomena in the determination of the laws of nature; languages are infinitely more volatile due to their abstraction, and the simile of linguistic change over time should, in my view, be taken with a grain of salt. Regardless, I feel that this brings up a salient philosophical principle - the concept of "ideal forms." We give names to things which we recognize to be those things, and we tend to have standardized conceptions of what those things are, based on certain criteria, context, and characteristics. Why is a cow a cow in English, but "una vaca" in Spanish? I find the Sapir-Whorf Hypothesis to be incredibly fascinating, if somewhat controversial - does the language we speak affect or reflect our worldview? Could it, by extension, impact the way we perceive and differentiate species of animals?
Though French wasn’t heavily influenced by Germanic languages the reason why it doesn’t sound like Spanish or Italian for example is mostly because of the Celtic tribes(Gauls) had a hard time speaking latin.
@@Strick-IX I think it's valuable to consider species to be dynamical systems rather than discrete objects. They are fuzzy concepts, that is they change over time and space. It doesn't mean the concept is obscurely philosophical, though it has philosophical overtones, any more than a storm is some sort of abstract ideation of the mind, rather than a discrete and very actual weather system you're caught in the middle of. So no, I don't think species as a concept has outlived its usefulness, nor that it is wrong in any way. It's not language forcing notions on the world of biology. It's a concept that's useful in some settings and less so in others, depending on the question under consideration.
@@Leszek.Rzepecki I never said that species as a concept has outlived its usefulness. I was merely stating that there is a certain subjectivity at play here; one that may vary from culture to culture.
Trying to define a species is like trying to define a cloud. From a distance it looks well outlined, with precise edges and a solid body against the blue sky. But as you get closer it looks blurrier and blurrier, until you don't know where it starts or where it ends. And when you got there, you can't tell the difference between the cloud and the sky
Definitions are agreed on subjectivity. It's amazing to watch how we hang onto them once their usefulness is exhausted, leading to a failure of the imagination necessary to figure it out.
Species, much like life itself, or sexes, are a case where "Theseus' ship" applies: You can easily determine the opposite ends of the spectrum, but it is virtually impossible to determine a separation line in the middle. You know that the ship started out as Theseus' ship, and you know that, in the end, it's not Theseus' ship anymore, but you can't say what was the exact moment it changed from one into the other, because this exact moment simply doesn't exist.
This kinda reminded me of the idea of social constructionalism. People often say that social constructions means that they aren't real but in reality its just means that's we as humans are trying to define something through lens that we value. These values can be logical, scientifically proven even but they're existence as a category depends on the human condition. As you mentioned in the video speciazation does happened and it does occur outside of the human condition but what makes it socially constructed is the fact that we are trying to categorizes it.
I spent some time on a farm with a variety of animals. There was a border collie that was laser-focused on the sheep, while completely ignoring the goats, even though they are close enough to produce (occasional, and generally stillborn) hybrids. The dog evidently had a concept of species or at least genera.
I love to attribute human qualities to my pets when I believe we are underestimating them as a culture, but I think this probably has more to do with their smell than a concept of speciation.
Something that is hard for people to get their heads around is how pretty much every category is a social construct. Even something that seems concrete like sex. These things are way more complicated and blurry than people think.
Many years ago in linguistics, a professor said offhandedly in class that "So-and-So does not believe that phonemes are not psychologically real." My immediate reaction was, "Of course, he's nuts." Each letter of the alphabet more or less represents a phoneme, and the IPA (International Phonetic Alphabet) would be impossible without the reality of phonemes. Or so I thought. Then, when studying artificial speech, I discovered that the concept of phoneme had impeded the development of the technology. The assumption that a word could be broken down into constituent elements called phonemes and then recombined into other words was the biggest obstacle to progress. Only when linguists gave up the idea of discrete phonemes could artificial speech recognition and production be achieved.
When I heard Richard Dawkins say that no animal was ever born that wasn’t the same species as it’s parents and the same species as it’s offspring it dawned on me that speciation is a man made concept. Useful but artificial.
Only because we are dealing with gradients. Species are different, there is a separation from a nodal point of a speciation event. Just because we put a label on it does not mean that that label isn't reflecting a real differentiation.
@@whatabouttheearth If it didn't, it wouldn't be that useful, but it's still artificial - most "speciation events" only look like events from a large distance. Up close, you can't see it, it's all a continuum. (Unless maybe in the case of founder effect.) Same with language, as has been mentioned by other commenters.
Most human concepts are just that, nature incorporates maths but it would not have a clue how to use a calculator. I think it is fair to say that from our perspective, speciation clearly exists but other than fot philosiphical or genetic engineering purposes, classification is pointless and a right royal pain in the arse. Perhaps it would be easier to say every individual is its own transitory species? Or give Guttsick and generations to come the job of defining each individual as multiple species? But, yeah, Typical Dawkins, posing questions but unable to actually give us the meaning of life, the universe and everything.
Species are an even bigger problem for creationists which is why they resort to "kinds". The prime assumption of creationists is the static nature of all life created exactly as it is now with no dynamism. Speciation is dynamic like cloud formation. A cloud looks like a face one minute and then it doesn't. Dynamism also means death because that which is dynamic is also mortal and that is all of us. Fear of death is REALLY what motivates creationists to be so irrational.
Your intro is probably my favorite of every UA-camr I've ever seen. Reminds me that I'm just the current link of a chain of organisms reproducing for hundreds of millions of years
Reality is significantly more complex than we generally need to consider. Most of us would agree that the boundary between male and female is fairly fundamental but for some humans the reality is not so simple. It can happen that hormone balances in the uterus during pregnancy can lead to the birth of a child that to all external appearances is one sex - then at puberty the apparent sex swaps. Female at birth to male at puberty is the most common such transition - but the reverse can also occur. This phenomenon is closely associated with the condition alpha-5 reductase deficiency where the body's ability to correctly process hormones is limited.. Similarly we tend to consider people as having a single genetic signature - but in some cases an individual can result from fraternal twins merging in the uterus to form a single embryo. We generally do not need to include such outliers in our deliberations - but it is always wise to bear in mind that things can get weird when we look closely at what's going on.
Except when making laws, I'd argue that we have to include the outliers in the deliberations - that falls under protecting minorities (which outliers are by definition).
@@KaiHenningsen I can understand why you'd think that, but in reality it is impossible to include all the possible outliers. That is why when it comes to law the interpreters consider not only the letter of the law (as it is written), but also the spirit of the law (as it is implied). For that reason all the work and documents that leads to making a new law is also considered during the interpretations in court. And when an outlier case is tested in court, that becomes a precedent for the future interpretations of the law.
@@Stratosarge I don't mean having a special rule for every possible outlier. I mean looking at outliers and seeing if, say, the categories the law puts people in actually make sense. For example, I don't need to know about every possible intersex condition to figure out that trying to absolutely separate people into men and women will lead to problems, and therefore I should probably figure out some better solution.
This is great at relating the complete interrelatedness of all life on earth. Essentially all descendants of the original organism, still technically part of an ongoing chain of splitting cells that's still going on after billions of years. Life is a soup more than a stew.
Not so sure about the original organism thing. unless a single rare catalyst arrived at some point, my understanding is it took billions of individual processes over milliones of years with an even bigger number of prototypes mixing and matching
We can be sure of one thing, "species" is a categorization that has been created by man to distinguish and classify the various lifeforms found on earth. It is not necessarily set in stone as future discoveries may redefine the boundaries of what a "species" means. However, no matter what, the categorization known as "species" is (and will likely always be) far more precise and detailed, not to mention accurate...than a "baramin".
The main thing that makes it pretty "easy" to sort most animals into different species is that most connections between the different species we recognize were so kind as to go ahead and all die, thus removing the inconvenient gray area in which we wouldve needed to draw that arbitrary line, and leaving us with just the pretty conveniently black and white ends that we can usually tell apart fairly easily. For now...
Species _can_ be difficult to define because interfertility does not abruptly end at a specific point in a gradient of genomic incongruity, but the fuzziness of a boundary does not demonstrate the nonexistence of that boundary; on the contrary, only existent boundaries can be fuzzy.
I really enjoyed this, it's a topic I think about a lot and it was great to see your take on it. Plus I loved the new animation (or at least animation I hadn't seen before).
Yes. This is also what is meant by non-dualism, and it is (scientifically speaking) totally rad. It's quite inspiring to see these concepts brought to bear on scientific thinking. Thank you!
This is similar to the problem in linguistics of distinguishing languages from dialects. Linguists can't agree on how different two dialects need to be to be different languages as opposed to dialects of the same language - there's even a version of "ring species" called "dialect continuum".
I’m glad you are stating this because I knew this from biology but wasn’t understanding it completely until I read Darwin’s book, and realized a hard stop would disprove Darwin.
This broke my brain as a kid. My donkey and horse had a baby and I like lost my mind. Thank you for making it make sense - because it doesn't make sense!
just to add to the breeding line of species: there are individuals of a "species" that are unable to reproduce or dont get to reproduce or maybe choose not to. the breeding requirement would exclude them from any species.
I am incredibly pleased to see you make a video where you spell this out so succinctly... I suspect that most people with a science background already understand this... but that many who lack a science background do not. It has always seemed obvious to me that many things actually consist of a gradient... and "speciation" is an obvious example of exactly that. (And that we humans often assign labels to specific points along that gradient merely for our convenience...) Gene lines continually diverge... one or two mutations at a time... so every individual is at least slightly different from every other. Therefore any criterion we choose to use to define a dividing line between species is bound to be somewhat arbitrary... But it is equally obvious that we need to assign some sort of labels to various points to facilitate meaningful discussions and comparisons... However an awful lot of people seem to lose track of the fact that the labels are just... labels... much as, in physics, models are just models... And this is obviously why so many creationists have such difficulty understanding evolution... The point isn't what they've chosen to describe as "kinds"... or what distinctions they actually choose to assign. The more basic problem is that they are literally unable to grasp the idea that there are gradients involved... They insist on treating the labels as "absolute separate things"... then cannot comprehend that "there are points on the line between the labels". It's somewhat obvious when you note how they phrase things: They always say "you've never seen a this become a that"... Rather than "you've never seen something HALFWAY BETWEEN this and that"... Without the concept of a gradient they simply cannot properly visualize the concept of "in between"... as being a point somewhere along a continuum. I suspect that it might make the subject more accessible to those without a science background if we carefully spell out what definition we're using. Or perhaps even forego using the labels in some instances... and simply instead use visual images to show the progression along the gradient. (In some vague colloquial sense assigning individual names to things tends to reinforce the notion that they are distinct and different rather than part of one continuum.)
Read up on Max Weber's "Ideal type". Its very helpful to understand that the terms we make up to describe complex realites shouldnt exist to put reality into little seperated boxes, but they are as an ideal type useful, so we can describe reality very closely if we compare the messy reality to an ideal type. Sure, its primarely for sociology or history, but a lot of things in natural sciences are so gradient and complex that it seems to me often useful there as well to imagine certain terms not as box labels, but as ideal types we could compare reality to. Always be aware that the end goal is not to assign certain terms to parts of our reality, but that these terms are just made up as a little tool to easier and better describe reality.
@@pi172 I absolutely agree... The problems arise when people start "mistaking the model for the territory" (to use Korzybski's terminology). And, in the case of creationists, they then use that error to justify claims that the knowledge underlying the model is incorrect. (Once you assign a name you then introduce the possibility that someone will claim you did it wrong... or in the wrong place... ) It is only the fact that we have assigned names to specific points in the continuum that enables them to claim that "one has never turned into another". I absolutely agree that it is both necessary and useful to do so... but maybe we need to explain it better. For example a typical creationist will say... "you've never seen a little shrew-like creature turn int a man"... The best response, which refutes this claim, is that yes both are simply points along a continuum... And that both are simply the labels that we've ASSIGNED to points along that continuous transition from one to the other... And so, yes, in fact, we HAVE seen one change into the other... and the demonstration of that is to look at all of the points in between... (We say that from time to time... but perhaps not emphatically enough or often enough to sink in.) To put that another way, for modern viewers, we should replace that "march of evolution" graphic with an animation showing a gradual continuous progression... (That would probably convey the idea much more effectively today... and eliminate any tendency to view the process as discrete steps.)
She's fantastic!..She doesn't go after the people that obviously don't have the background, she explains..She lets who she's debating set the rules of conduct..like she says..its fun...You could have saved yourself and your readers some time by saying..."If we teach people the scientific process , those with a limited scientific background would have the tool they need to research the info themselves...or turn them on to Feynman's words "It doesn't matter how beautiful your hypothesis is, it doesn't matter how smart you are. If it disagrees with experiment, it's wrong." - Richard Feynman..
@@keithlevkoff8579 There are two problems. One is that an animation is better than a static picture - see the animation at the start of most of Erica's videos, which does exactly that! But second is, it's not a linear progression, it's a tree. That's much harder to show.
9:05 My solution to this ring species problem: Allow organisms to belong to multiple species. Lizards A and B can share a species classification; Lizardus imaginaro Lizards B and C can share a species classification; Lizardus examplifico Lizard B belongs to both species. Lizards A and C do not.
We use calendars and clocks to subdivide and differentiate one moment from another, but...while time is real...our demarcation (1) is man-made and (2) has variable results due to relativity. As pertains to the conversation about species, discerning a fish from a bird is as easy as discerning Summer from Winter (outside the tropics), but discerning two different _Species_ of bird within the same Genus may be as difficult as telling the difference between two different Winter _minutes._
From the perspective of deep time, "living things" are a continuous line. So when we define a species it has to be defined by a given period of time. A species is a group of interbreeding individuals defined by time and geographic location. A species is an artificial designation of convenience, similar to grouping organs into "organ systems" when studying anatomy (since systems don't really exist). Just because we have a word for something doesn't mean it physically exists; it might simply be a "fuzzy" concept.
An important thing for people to realize is taxonomy isn't a science. Despite what some dictionaries say taxonomy is actually just a system of classification. A system of classification that uses physical differences, genetic differences and in most cases arbitrary human opinion to decide which populations of organisms are different from others. Its humans trying to draw lines in the very messy, interconnected, billions year old story that is life on Earth.
@@whatabouttheearth It's very similar to what librarians do when trying to organize books. Genres are constructs in the same way species are - if anything, they are even fuzzier because books don't really evolve.
@@KaiHenningsen Right, but a differentiation of genetics does actually happen. A fuzzy attempt to categorize a certain area of demarcation is not not reflecting a reality. Just because I try to categorize mile markers between 155 and 355 when 155 is after a certain off ramp and the entire road is a gradient of sorts leading from one inch to the other, from mile marker 1 to 100,000 does not mean that that construct of spatial categorization isn't an attempt at reflecting a measurement of the real. A signifier is still a real refference to the signified even though it falls short in describing the signified. To put it simplistically, closer to a nodal point of speciation divergent two lines can still interbreed fertile offspring, the more distant they become they can only breed infertile offspring, and there is an overlap between those two zones of separation, eventually with even further distance the two lines can no longer breed offspring at all. So something is happening and that thing we categorize as a divergence of species. To try to make our categories and constructs more accurate is one thing, but to act like they are illegitimate because they are constructs, human made organizational tools, feels akin to self defeating post modernism or something. It's akin to acting like measurements on a ruler are not "real", you need to try to work with something. Species come from ancestral lines, so it is not as confused as book genres. There is a real ancestor/descendant relationship in biodiversity. Nature doesn't take something genetic from five genera, families or orders distant cousins away, but that is what happens in genres of art. There is a real, historically objective and tangible genetic descendant relationship in nature (not counting microscopic shit because they're freaking bizzare)
@@whatabouttheearth its interesting you bring up mile markers because reflects a problem with taxonomy. There is no standardization at all (and I don't know if there could be). Every group of taxonomist has their own criteria for what is a species/genus and what isn't. Ornithologist separate some bird species by solely by call, herpetologist lump all monitor lizards into the genus Varanus (other group of zoologist probably would have that made into 5-20 separate genus), 'Spirit Bears' get their own subspecies of American black bear despite only having their color due to a recessive gene. When you get past genus and sometimes family it kind of becomes a free for all. The reproduction rules for species seem to work well for mammals but fail in many ways for reptiles, fish and plants. All pythons can reproduce, and make offspring capable of making F2 hybrids. American paddlefish and Russian sturgeon can hybridize despite diverging in the Jurassic.
@@caseycannon1038 Yeah, I can see how standard for defining a species should maybe change for various levels like kingdom. As is always said "nature does not like to be pigeon holed" 😂 Shit, all I want is for animal and botany taxonomists to have the same prefixes for basic classification levels like genus, family and order. Taxonomy is never ending new vocabulary, there's Latin, Greek, Chinese, English, Japanese, South African, Patronyms and god knows what else
Let’s just say a species is a group of genetically and behaviorally distinct animals which also fill a different role than other species (ie; Different geographically, different niches, etc)
Excellent! As a avid fish hobbyist I have been super frustrated with species definition for years and always felt it was crazy to try to impose such an arbitrary rigid definition upon something that was clearly a gradient. I did not know of all the competing models out there. I learn so much from watching your videos!
This was an excellent video! As a layperson, I was able to understand on most of the surface level what you were discussing. I have an interest in the many branches of science and watching your videos has inspired me to take an academic approach in the field again. Thank you for everything you do here.
It's a problem because we want "species" to be an equivalence relation. That's an idea from mathematics. The definition goes like this: You've got a set of objects, and for any two objects, call them a and b, it might be true that a~b, read "a is equivalent to b." Or it might not be true. But ~ is an equivalence relation if it follows these rules: 1) It's reflexive. This means that for any object a, a~a. 2) It's symmetric. This means that for any two objects a and b, if a~b then b~a. 3) It's transitive. This means that for any three objects a, b, and c, if a~b and b~c, then a~c. Okay, so what if we look at the set of organisms, and ~ indicates that two organisms are part of the same species? Well, ~ is clearly reflexive and symmetric. I don't think we run into any circumstances where it's a problem to say that a creature is the same species as itself, or where creature a is the same species as creature b, but not the other way around. However, we do run into problems with transitivity. What I'm wondering is whether there's a definition for species that works in every respect, aside from not being transitive.
Isn't this why we use the clade system now and not the kingdom, family, etc taxonomy I learned in elementary school. I am just a hair older than rocks, so I hope we have learned a lot since then. Not that I mind a good smeckledorphing, but you make me feel cheap and easy.
I am quite comfortable with the concept of species. Since nobody is comfortable dealing with deep time and the continuum of life over billion of years, the species concept gives us common ground to discuss a population, existing currently or extinct. I like. It to pulling a few individual frames out of a movie. The still are not as rich as the movie but still useful.
I didn't know that ligers could reproduce. I always thought they were sterile like the mule. Here's something I just read: "The fertility of hybrid big cat females is well documented across a number of different hybrids. This is in accordance with Haldane's rule: in hybrids of animals whose sex is determined by sex chromosomes, if one of the two sexes is absent, rare or sterile, it will be the heterogametic sex. Male ligers are consequently sterile, while female ligers are not."
Like most things in the natural world, it's fuzzy around the edges. Nature just doesn't work in the paradigms humans create to make thinking easier. In short, it's complicated. Fabulous video! Thanks!
I like YOUR definition: A static description of individuals and groups that are part of a dynamic process. That gives science the leeway it might need to change a destination when nessisery.
I've always thought of "Species" as a combination of the two concepts, morphology and genetic relation. Always keeping in mind that reality is more complicated that the labels we use to describe it.
Philosophy of science seems really important, surprised more people don't talk about it more often. This type of stuff is generally dipping into Metaphysics, and to (some) philosophers wouldn't be very controversial. There should be more overlap more often, would make for more interesting conversations.
There was a Brain Scoop episodes about Grey wolves that kinda talked about this. Turns out coyotes and grey wolves can have hybrid offspring that can reproduce. Now this becomes a problem because grey wolves are protected under the endangered species act. So how much coyote genetics need to be in a grey wolf before it is no longer considered grey wolf and protected?
Species are in fact widely considered “real”. In fact many would view species as the ONLY real taxonomic rank. Species are independently evolving population lineages with unique combinations of coadapted genes. Because species are the result of a historical process and as such they will be difficult to delimit early in their divergence. The same could be said for any biological entity emerging from a contingent historical process. We don’t say children and adults aren’t real biologically meaningful categories just because they are a product of development. Don’t conflate species concepts with species delimitation. Species are in fact real evolutionary and population entities.
I think there is another way to fix this process by creating two new categories of Subspecies 1. Domain 2. Kingdom 3. Phylum 4. Class 5. Order 6. Family 7. Genus 8. Species-Can reproduce 9. Breed-Major Physical Differences due to geological range 10.Variant-A group of individuals with small inherited physical differences (Color, Smell, Digestion, Immune System) 11. Individual
Obviously, it reduces to "a population that biologists agree to call a species", which of course is unsatisfactory. But language is full of such terms. Just because it's not absolute doesn't mean it's not useful. Heck, it's true of "life" itself! Just recognize that fact and go on, I say.
Well, the issue is, that biologists cannot agree to one single definition, this is what the species problem is about. Each one of the proposed definitions is demonstrably wrong in some cases. This obviously can lead to communication issues, it can lead to wrong conclusions, which is not a major issue for most of us, but it can be for biologists. So it is important to know, that species cannot be defined in a consistent way, and understand the limitations of each definition. I can agree to the conclusion, recognize the issue and go on :)
We talk about this a lot in music theory. There are a lot of concepts in music that describe systematically what sounds good and proper to a certain audience, and which are useful for communicating about music and as tools for composing music. But people try and apply a certain set of these, especially European music concepts, as if they were absolute rules that apply to all music at all times. Which is absolutely futile and leads to many of the same frustrating conversations as attempting to unify species concept.
As a music history/literature major with a minor in anthropology (my field was ethnomusicology), I must give you MAJOR credit for this post. You're probably the first person on UA-cam to recognize the value in music theory, as well as the problems inherent in applying the rules of the common practice period (roughly 1500-1880 if I remember correctly after 17 years being out-of-practice) to situations in which they are clearly incapable of being used meaningfully. In fact, check out the score for Penderecki's "Threnody for the Victims of Hiroshima", some Ligeti piano studies, OR basically anything by Karlheinz Stockhausen. They had to come up with entirely new notation systems. Also, ethnomusicologists have been doing this since the field was born (~1930, but not officially until ~1950). I remember being given a cassette tape of Ethiopian liturgical chant; the other ethno student and I were given TWO days to transcribe at least three minutes of it. (1) My MUHL/ethnomusicology professor trained us in South Indian Hindu temple percussion; I think I'm pretty good at sniffing out rhythms and meters. I could NOT figure out the rhythmic cycle (time signature) for this piece) because every evenly-spaced pulse was going about ~25 BPM. Punctuated with a seemingly-random blast from a low-pitched drum. ANSWER: It was in a seven beat cycle, about 50 BPM. (2) It was completely monophonic. The closest pitches I could assign to the first two syllables were B-natural, E-natural, but they weren't using our tuning system; I could hear quarter-tones and even the central pitches were not perfectly in tune with E = ~330 Hz. Then, insult + injury: All of the pitches were connected; the singers glided from one pitch to the next. ANSWER: Using standard staff paper, I tentatively transcribed the piece in E minor, and used a calligraphy pen's thin-to-thick writing style to show the glides. Because I couldn't nail the meter, I carefully penciled in dotted bar lines at even intervals, each representing 1 second. I got an A for stealing from Penderecki both in my pitch notation style and my "timed" bar lines. I openly admitted to stealing the ideas and he said "If it works, use it, yeah?". My buddy got an A because he cracked the "meter" problem by taking the tape and speeding it up something like 3x. But he didn't provide any notation. Instead -- I shit you not -- his presentation on notation was to have us listen to the song "Brain Crack" by Tracy Bonham to give us an idea of how he felt for 2 days (available here: /watch?v=2SI_c78BbME
This made me glad that people lots smarter than me are going to sort it out. What a great explanation of the advantages and disadvantages of our system-now I know lots more. Thanks.
We fondly dedicate the following poem to this video of yours. The poem is titled "Theogony": Nothing is real, Above the empirical seal; Systems and superorganisms as well, All in the depths of hell; The constants and patterns to know, They all lie below.
A biologist, a creationist, and I walk into a bar... The biologist orders a Bud and a Michelob, mixes them, takes a taste, makes a face, and proclaims: "These are different and demonstrably do not mix well by way of statistical data suggesting very few proceed to do what I just did." The creationist orders a Guinness draught and a Guinness blonde and proclaims, "I do not mix beer of different kinds." I order a Lowenbräu and a Meisterbräu, mix them, take a drink, and proclaim, "Unibräu!"
Accept that reality is continuous, any attempt to make it discrete will result in fuzzy boundaries. Species, mountains, oceans, continents, planets, national boundaries, cultures, languages, sexuality, etc. It’s like trying to make flat maps of the earth. Useful, but inherently limited.
Species, as per my take: A specific contempory genetic branch of organisms that are distinct in various ways enough to be catalogued in a manner useful for human analysis.
@Stirgid Lanathiel I think the idea of a hard line is the inherent problem. Perhaps maybe "A group of contempory organisms, sharing genealogical ties through sexual or asexual reproduction, that are often perceivably distinct and share a spectrum of physical and genetic characteristics sufficient enough that a majority of specialists would agree to it being worth categorizing for reference and cultural edification." "Contempory" was always the key word there though. The spectrum blurring the further in either direction you go between the individual's generations. Would make a lot of sense to include the year along with the traditional species name. Homo Sapiens Sapiens 1900, or the like.
@Stirgid Lanathiel That was my point about contempories, that erases the fuzzy edges almost entirely. The fuzziness that remains is purely one about chronology, and that goes for everything from families to fundamental physics. Do families not exist? Species, families and all these things are definitely a chronological spectrum. The closer we look at absolutely anyhting, the fuzzier it gets. What are fundamental particles made of? What are waves made of? What is space-time made of? Everything is a spectrum that we place things on, being surprised that species are a spectrum as well is naive. At least with species we have a clear understanding of where that spectrum stretches.
@Stirgid Lanathiel My point is embracing that these things exist on a chronological spectrum. Zoom in and there is and individual person, zoom in closer and we have individual organs, zoom in closer and we have cells and the interacting micro-biome. Zoom out though and an individual person becomes a unit consisting of two biological parents. Zoom out again and you'll have a larger unit, and so on until we are both contained within the same unit. Having looked into this further, I guess you can say I'm a proponent of the genealogical concept of species. Another commenter named "Les Freres de la Quote" made a beautiful comparison to language and the concept that perhaps it would be better to think in terms of how much energy, or in my case how many familial steps, it takes to define the concept. You are right though, and it's my opinion that embracing the fuzziness as an intrinsic part of reality still allows for proper categories. After all, it is humans that will decide how wide of the spectrum they will encompass within any single unit or category.
A good example of how Mayr's definition fails is seen in two fish commonly kept in home aquariums. - Xiphophorus maculatus (southern platyfish) - Xiphophorus hellerii (green swordtail) Same Genus, but different species. These two can readily mate and produce viable (non-sterile) offspring. Furthermore, if Spock is not sterile, then humans and Vulcans are the same species (by Mayr's definition).
The problem was succinctly stated by Einstein as thus, " As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.” More generally, "As far as the models of science refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.” There was a famous experiment regarding this conducted by Richard Feyman. He changed freshman Physics at Caltech from Newtonian to General relativity. And failed. What's going on here? Well, to the extent that a model can be used to control and manipulate the world through engineering and manufacturing, the model is useful. General Relativity is a more precise model than Newtonian physics but most of the time all you need is Newtonian physics. Models will always be imprecise. The standard for which imprecise model to use is strictly practical. If 99% of modern medicine can be implemented using reproductive specie definition then get on with it. Finally "real" as used in this video is unhelpful. Someone once noted that the use of the word "real" is the only word that should always be used in air quotes. A better question is which definition of the word species has the most applicability in building models for engineering and manufacturing, especially in medicine. Once one gets over the concept of precision then one can settle in on application. Yes, there is no universal definition of "specie" that can support all models. But if there is one that gets the job done for most models it should win the day as the unqualified word and then all other models qualify the word specie to import a different definition required for the model.
One minor point - "species" is both the singular and plural here. Once you start talking about "specie" you are actually discussing coinage, not biology.
I think the term "species" applies best to current day things, something we right now would consider separate from another thing. Like with people albeit much less varied than all of animalkind. Looking for various ways to separate ourselves from each other when in reality we're all distant relatives. But for us and how we defined the family, calling everyone a distant relative as opposed to brother, sister, cousin, father, mother, friend, stranger, etc. would kinda kill any way to classify each other in that more specific manner
I work in parrot rescue and we are constantly confronted with the inadequacy of the biological species concept. Sun/Jenday/Goldcap conures are a line species, while the famous Wild Parrots of Telegraph Hill (the birds I work with) are a fertile hybrid of Mitred (Psittacara mitratus) and Cherry-headed or Red-masked (Psittacara erythrogenys) conures. Before the genomic restructure of the Psittacidae family, it was even possible to hybridize across genus boundaries, tho these cases were mostly restricted to forced pairing by evil parrot breeders.
It’s great to see young people discover and rediscover the limits of categories. This is not limited to species of course. The journey leads eventually to the emergence of order in self-organizing systems through synergetic thermodynamics.
There has always been order in the universe. Or there has always been chaos in our universe. Whichever or use another word, it is just semantics and humas trying to catagorise things
@@josmith9662 True. Although I have to admit that the process of categorizing things is quite important for mobile life - because orientation/navigation needs categories to create patterns for decision-making. It's not trivial at all.
A snapshot based on generalizations, averages, and ranges, and using different lenses (aka definitions). What is a man (besides a miserable pile of secrets)? Like what characteristics make a human? Size is incredibly variable: from the smallest born human to the largest who ever lived. Body plan? You can be born missing limbs or have extra. Even missing parts of your brain. Genetics should be fairly definite though? Not unless you want to argue that people with Down, Cri-du-Chat, or Turner Syndrome are somehow less/inhuman. Species as a concept is definitely useful, but it cannot be usefully defined in a way that doesn't lend itself to many exceptions, even in the context of just being a snapshot in time. This isn't me arguing against what you wrote, but moreso expounding my own thoughts in relation to it.
This is so good. I totally get that GG's approach takes a naturalistic approach but there is an important - even vital - "moral" implication here. I think it is a very good thing indeed that we be constantly reminded of our place in the universe ... it is not central! Being part of life's flow is value enough - or should be - but for various reasons we find this hard to accept.
I'm doing my honours in evolutionary biology right now and this is something that directly relates to my project. It's tantalising but frustrating how species are ultimately arbitrary but also so useful.
You have to also throw in that hybridisation is often the starting point for periods of speciation, and that horizontal gene transfer often happens between just about any living thing regardless of species. Big leaps in evolution often happen when novel genes are transferred. For example a key protein for the development of the placenta likely arrived via a virus. I prefer to think of species as being like pools of water or oceans, interconnected by rivers and channels of varying flow rates, constantly merging and separating over time.
I thought Ligers were infertile. But I am no expert... I do know of many successful hybrid snakes, since the wife and I delved into Ball Pythons and their breeding... I have seen Australian and African pythons hybridized... Not sure about the reproductive viability of the offspring... But Borneo Bateaters (Burmese x Retics) are viable, Burm Balls (Ball Python x Burmese) are readily available for purchase...
It astounds me how you can equate ligers to hybrid snakes. Snakes are snakes. Do I need to repeat that for you? Snakes are snakes. They should literally all be able to breed amongst themselves freely. Tigers are not lions.
@@harryosborne8215 I wasn't equating anything. I was making an observation. A Ball Python isn't a Carpet Python, they are in a different genus. I have not seen any hybrids of say Colubrid to Python, crossing different families. Lions and tigers are in the same genus. So I really don't see your point.
@@dracdrum Only male ligers are sterile in accordance to Haldane's rule. The reason male hybrids are usually more likely to be sterile compared to their female counterparts is because males have two different sex chromosomes.
Glad to see that astronomy isn't the only field of science dealing with this (classification systems for celestial bodies fall flat each time a new discovery is made).
Brazil faces this same problem. could you make a video talking about creationists in politics and medicine and music etc in the USA. and please subtitle it in portuguese would help America a lot. and you would have a lot of visualization. if you can put it in spanish too
Thumbs up. Very interesting indeed, and I guess... yeah... nature doesn't care about our need to categorize. It's nice enough to know we are connected to all life.
The problem is species are analog, not digital. They don't have definitive start and stop points, they flow gradually from one into another.
Not only that but it's got noise too. Any one individual isn't going to have exactly the same traits as average, and often individuals might have quite different traits.
Speciation is as much arbitrary segmentation as the hour or the minute.
Nice summary of my diatribe. It's a meaningful distinction without a meaningful definition. What second, minute, hour or day does an adolescent become an adult? You know it when you see it, but you cannot pinpoint when it occurs. Perhaps one day we'll have the resolution needed to define species, but not today.
Species are great for describing differences in life-forms, it does not provide an absolute explanation - oh well
Exactly... however, not only do we humans prefer to label things, but we have become accustomed to seeing them that way.
And, even beyond that, it could be claimed to be an actual feature of how our thoughts are structured.
And, likewise, when we see pictures of primates or other species in textbooks, those also virtually ALWAYS have a specific label...
(And just try to find a nature show on TV that neglects to NAME every single animal they show.)
We virtually never see one labeled as "halfway between this and that species"...
In fact, when we discover one, almost the first thing we do is to rush to CREATE a specific label to go with our new discovery.
It would be more accurate to simply use dates... and technical details... but we humans find that to be so cumbersome as to be unworkable...
But, however useful this is, it does "program" us to see things in distinct categories or cubbyholes.
I work in the audio and home theater industry... and every day I see this issue... in reverse.
Many people are virtually incapable of understanding how a series of digital "numbers" can accurately represent an analog signal.
They are apparently simply unable to see the two as different representations of exactly the same thing.
I don't understand how you can put so much effort into explaining and articulating this so well, and yet some people still take away "evolution is stoopid". Well done, as always
That's because they themselves are stupid and blame the concept when theu aren't capable of understanding it
@@MegaeffinGarchomp17 I suspect it has more to do with their biases.
✌👉 The Connections (2021) [short documentary] 💖✌
@@MegaeffinGarchomp17 People tend to value personal and social comfort, we don't really gain benefits out of "the truth".
If you live in a group, which sees evolution as a threat, or have a world view, where evolution doesn't fit, it is much better for this person to deny evolution, especially if it has zero impact on their daily live. Truth is only valuable, if you face environmental issues, which you need to solve and need to understand the issue first. However, that evolution is not a day to day problem for most people, so it is cheap to deny. Of course, there is a long term cost, but people are very bad in taking long term problems serious (all of us).
In that sense, it is just logical to deny evolution (for them).
At least, that is how I rationalize it (haven't found anyone to talk to personally, who denies evolution)
What people seem to not understand is that "species" are stupid because everything is stupid
This reminds me of the "coastline problem " in geography where trying to map out the coast of a country is actually rather problematic when you get closer to smaller units of measure.
The name of the mathematics is fractal length of a coast line. 0 for a dot, 1 for a line, 2 for a square, in that measurement many coastlines are ~1.5. The Norwegian coastline has highest dimension.
Fuzzy math/logic is part of the real world. That is another example of the lack of a binary answer. Erica is acting as if reality is binary. Its fuzzy. Even at the lowest level of physics.
The species problem also seems to be somewhat fractal in nature. Lots of self similarities AND differences depending on which path you take. However, on the topic of definitions, even if you can't come up with a perfect all-encompassing definition of species it's not an entirely useless concept. You just need to remember the lines are fuzzy and don't always apply.
@@ethelredhardrede1838 "Erica is acting as if reality is binary. Its fuzzy." - I think you need to re-watch. She just explained that biology is not binary.
"Even at the lowest level of physics" - totally unrelated.
@@freddan6fly
I had no problem with watching it. She understood that it is not binary but is insisting that species must be defined as being binary or they don't exist. That is where her error lies. Mayer's definition is more than adequate for sexualy reproducing in more than 90 percent of them at any giving time.
It's not a merely human definition, it's a description of sexualy reproducing organism actually function. The purpose of the term is to communicate, not to force a concept on reality.
Species exist in real life, that is why the term is useful to communicate. That it's not binary as Erica is insisting it must to be real does not make any less useful to communicate. What does she want to replace it with? An essay each time that a single word will do?
"Never conceivably interbreed in nature" (5:40), nice play on words.
Defining "species" is troublesome because it's a _static_ concept applied to a _dynamic_ process. That's easy enough to remember, thank you!
In one of his more recent books (I forget which) Dawkins makes the statement that every organism has been and always will be the same species as its parents, a statement that, taken out of concept seems to contradict evolution, especially for people who don't understand evolution. But knowing it as a gradual and dynamic process, with complications such as hybridization, that makes sense.
It's the problem of the heap. A grain of sand is clearly not a heap of sand. But if you add a grain at a time, at some point you will have a heap. But there's no clear line when it becomes a heap.
That would be like the ring species problem except instead of the distance being in geography the distance is in time.
@@coweatsman The Ship of Theseus may be a better analogy than the heap of sand problem.
I read this as she said it. Nice!
The basic problem here is, you start with two things considered equal, but very slowly there is an increment in diferences, so you need to decide when those two things can not be longer classified as 'equal' but 'different'.
I still think that is possible a better definition of 'species', but involving mathematical modelling and measuring the amount of change over time. A species could be a group of organisms that stays within less than x amount of change involving at least y generations. The 'procreating with your own kin' thing should be considered a factor that helps in the creation of species instead of a defining factor of the definition.
The animation at the beginning reminded me so much of those “who’s that animal?” animations that used to play in Zoboomafoo.
Always good to remember that so many things in our world are not "real" in the sense that they are manmade concepts in a (desperate) attempt to make sense of the world we live in. They can still be incredibly useful though.
Yet I've also come to think that, in a weird way, as long as someone has thought of them, those things are "real". Take a fictional character for example. They can have a profound impact on "real" people and influence these people as much as "real" people do, and yet they themselves are not considered "real".
And what is "real" anyway? In the end we humans are just a bunch of complicated chemistry that has developed the emerging property of being hyper self-aware. Being alive and aware is scary and things often get so, so fuzzy. That's why so many people turn to religion and other superstitions, it gives them the reassuring feeling of being able to make absolute sense of the world.
The longer I live the more I've come to think that in reality there are very few things about life and the universe one can say with reasonable confidence are absolutely certain...
I agree to some extent, species are real, only they are a fuzzy concept rather than a discrete one, and this is because a species is a dynamic system.
A single object that doesn't change with time can be defined uniquely: a cube is a cube... is a cube, and doesn't turn into a sphere or tetragon. A storm, on the other hand, is an identifiable system - you know when you are caught in one and satellites can tell you its size, speed and therefore duration, but it's not isolated from the other weather systems on the planet, which all interact.
So I disagree with the simplistic assertion that "species don't exist." They don't exist as unchanging and discrete systems. They do exist as dynamic ones.
Making sense of our world by giving things names and catagories is not so desperate, in fact I would suggest it is a very sencible thing to do.
Real is real, thats why there is science and plenty is certain, albeit humans have a history of wild speculation.
I think what you are suffering from Sir or Madam is a mid life crisis.
Gutsick on the other hand may well be mixing druggies and knowledge to great effect?
@@Leszek.Rzepecki Thank you for the valuable input. I pretty much think the same.
@@Leszek.Rzepecki The storm is a good analogy Lasek, but is the cube as good? A physical cube too is really in a state of change, usually a much slower process is at work - depending on the material you build the cube of.
Unless of course you were referring to a cube in the conceptual sense. The concept of a cube is not subject to the forces of physics. But can it be said to exist outside the collective consciousness of man? As we have not yet found another animal with such arcane concepts, it must be an open question.
@@John.0z I suspect he means a cube as in a regular hexahedron.
I really appreciate your content Erika. My most recent formal biology class was a 5 credit Bio 101 course in 1981. Videos like this really help me to stay at least somewhat up to date with developments in the field.
Wow, you're gullible
Oh god no please do not get your science from commentary UA-camrs
@@recreant359 It helps in furthering knowledge, so no, there's nothing inherently wrong with it.
@@recreant359 Professor Dave helped me through part of my degree in biology with his vids, and Erica is exceptionally knowledgeable vis a vis primate evolution and biology. Yes books, and peer review are excellent, however, they can be very dry, an d this is where these videos come in useful. To give an introduction to or to explain difficult concepts, so that one has a better understanding of what they are going to read, when they go to read the paper, or book.
As it is often mentioned, there is a lot of parallel with how languages evolved. My mother tongue is French. I speak a romance language, which is the language family to which Italian, Spanish, Portuguese or Romanian belong to. Learning one of these languages require much less effort for me than for someone who would speak Japanese. I went to Cuba a few years ago, and it took me only a few days to learn some basic phrases, which all presented some regular variations with French. After a week I could understand some basic Spanish. Italians or Spaniards who come to France can learn the language in a few months compared to someone whose mother tongue would be Russian or Chinese. When the Latin language started to evolve in different dialects, people could understand each other from valley to valley or river banks to river banks. However, two centuries later, someone from the North of France would have had a hard time to understand someone from the South of Spain. Since, animals are often a genetic continuum, I would think that the only way to differentiate species would be to use a notion of energy. How much energy is required to jump the genetic or geographic differences between animals? For instance, it takes more energy for me to learn Romanian than Italian, since French and Romanian evolved in very different cultural environment. French was heavily influenced by Germanic languages and Romanian by Slavic languages.
Excellent point, because language is copying with variation (or errors) and selection, just like genes.
Personally, I wouldn't say it's a 1:1 comparison when it comes to linguistic evolution and physiological/genetic change over time. Languages are, like the species concepts mentioned in this video, largely semiotic constructs which help us convey ideas and make sense of the natural world; the selective pressures can differ dramatically. In order for a an animal to "jump" the genetic differences between animals, no amount of energy would allow a kangaroo to reproduce with a dolphin (at least, I don't think so - that would be a sight to behold, though). Geographically speaking, factors like migration can vary widely in terms of time and distance. Likewise, as we must consider a vast array of ecological (and sometimes social) phenomena in the determination of the laws of nature; languages are infinitely more volatile due to their abstraction, and the simile of linguistic change over time should, in my view, be taken with a grain of salt.
Regardless, I feel that this brings up a salient philosophical principle - the concept of "ideal forms." We give names to things which we recognize to be those things, and we tend to have standardized conceptions of what those things are, based on certain criteria, context, and characteristics. Why is a cow a cow in English, but "una vaca" in Spanish? I find the Sapir-Whorf Hypothesis to be incredibly fascinating, if somewhat controversial - does the language we speak affect or reflect our worldview? Could it, by extension, impact the way we perceive and differentiate species of animals?
Though French wasn’t heavily influenced by Germanic languages the reason why it doesn’t sound like Spanish or Italian for example is mostly because of the Celtic tribes(Gauls) had a hard time speaking latin.
@@Strick-IX I think it's valuable to consider species to be dynamical systems rather than discrete objects. They are fuzzy concepts, that is they change over time and space. It doesn't mean the concept is obscurely philosophical, though it has philosophical overtones, any more than a storm is some sort of abstract ideation of the mind, rather than a discrete and very actual weather system you're caught in the middle of.
So no, I don't think species as a concept has outlived its usefulness, nor that it is wrong in any way. It's not language forcing notions on the world of biology. It's a concept that's useful in some settings and less so in others, depending on the question under consideration.
@@Leszek.Rzepecki I never said that species as a concept has outlived its usefulness. I was merely stating that there is a certain subjectivity at play here; one that may vary from culture to culture.
Trying to define a species is like trying to define a cloud. From a distance it looks well outlined, with precise edges and a solid body against the blue sky. But as you get closer it looks blurrier and blurrier, until you don't know where it starts or where it ends. And when you got there, you can't tell the difference between the cloud and the sky
So Terry Pratchett
Where does orange start and yellow end?
Definitions are agreed on subjectivity. It's amazing to watch how we hang onto them once their usefulness is exhausted, leading to a failure of the imagination necessary to figure it out.
Species, much like life itself, or sexes, are a case where "Theseus' ship" applies: You can easily determine the opposite ends of the spectrum, but it is virtually impossible to determine a separation line in the middle. You know that the ship started out as Theseus' ship, and you know that, in the end, it's not Theseus' ship anymore, but you can't say what was the exact moment it changed from one into the other, because this exact moment simply doesn't exist.
This kinda reminded me of the idea of social constructionalism. People often say that social constructions means that they aren't real but in reality its just means that's we as humans are trying to define something through lens that we value. These values can be logical, scientifically proven even but they're existence as a category depends on the human condition. As you mentioned in the video speciazation does happened and it does occur outside of the human condition but what makes it socially constructed is the fact that we are trying to categorizes it.
I spent some time on a farm with a variety of animals. There was a border collie that was laser-focused on the sheep, while completely ignoring the goats, even though they are close enough to produce (occasional, and generally stillborn) hybrids. The dog evidently had a concept of species or at least genera.
I love to attribute human qualities to my pets when I believe we are underestimating them as a culture, but I think this probably has more to do with their smell than a concept of speciation.
That odour is a component of the differentiation does not make the dog's concept of species any less valid than those of humans.
Or maybe he just got his butt kicked by one of the things with horns and now avoids anything with horns? :)
Something that is hard for people to get their heads around is how pretty much every category is a social construct. Even something that seems concrete like sex. These things are way more complicated and blurry than people think.
Many years ago in linguistics, a professor said offhandedly in class that "So-and-So does not believe that phonemes are not psychologically real." My immediate reaction was, "Of course, he's nuts." Each letter of the alphabet more or less represents a phoneme, and the IPA (International Phonetic Alphabet) would be impossible without the reality of phonemes.
Or so I thought. Then, when studying artificial speech, I discovered that the concept of phoneme had impeded the development of the technology. The assumption that a word could be broken down into constituent elements called phonemes and then recombined into other words was the biggest obstacle to progress. Only when linguists gave up the idea of discrete phonemes could artificial speech recognition and production be achieved.
When I heard Richard Dawkins say that no animal was ever born that wasn’t the same species as it’s parents and the same species as it’s offspring it dawned on me that speciation is a man made concept. Useful but artificial.
Only because we are dealing with gradients. Species are different, there is a separation from a nodal point of a speciation event. Just because we put a label on it does not mean that that label isn't reflecting a real differentiation.
@@whatabouttheearth If it didn't, it wouldn't be that useful, but it's still artificial - most "speciation events" only look like events from a large distance. Up close, you can't see it, it's all a continuum. (Unless maybe in the case of founder effect.) Same with language, as has been mentioned by other commenters.
Most human concepts are just that, nature incorporates maths but it would not have a clue how to use a calculator.
I think it is fair to say that from our perspective, speciation clearly exists but other than fot philosiphical or genetic engineering purposes, classification is pointless and a right royal pain in the arse.
Perhaps it would be easier to say every individual is its own transitory species?
Or give Guttsick and generations to come the job of defining each individual as multiple species?
But, yeah, Typical Dawkins, posing questions but unable to actually give us the meaning of life, the universe and everything.
So, a wolfdog is a wolf ... or is it a dog?
Species are an even bigger problem for creationists which is why they resort to "kinds". The prime assumption of creationists is the static nature of all life created exactly as it is now with no dynamism. Speciation is dynamic like cloud formation. A cloud looks like a face one minute and then it doesn't. Dynamism also means death because that which is dynamic is also mortal and that is all of us. Fear of death is REALLY what motivates creationists to be so irrational.
"Reproductive isolation."
Diogenes drags 4chan into the room: "BEHOLD, A SPECIES!"
Been a while since I laughed out loud on a comment, thank you 😂
Your intro is probably my favorite of every UA-camr I've ever seen. Reminds me that I'm just the current link of a chain of organisms reproducing for hundreds of millions of years
You nailed it perfectly... We attempt to give static definitions to dynamic processes.
Reality is significantly more complex than we generally need to consider.
Most of us would agree that the boundary between male and female is fairly fundamental but for some humans the reality is not so simple.
It can happen that hormone balances in the uterus during pregnancy can lead to the birth of a child that to all external appearances is one sex - then at puberty the apparent sex swaps. Female at birth to male at puberty is the most common such transition - but the reverse can also occur. This phenomenon is closely associated with the condition alpha-5 reductase deficiency where the body's ability to correctly process hormones is limited..
Similarly we tend to consider people as having a single genetic signature - but in some cases an individual can result from fraternal twins merging in the uterus to form a single embryo.
We generally do not need to include such outliers in our deliberations - but it is always wise to bear in mind that things can get weird when we look closely at what's going on.
Except when making laws, I'd argue that we have to include the outliers in the deliberations - that falls under protecting minorities (which outliers are by definition).
@@KaiHenningsen I can understand why you'd think that, but in reality it is impossible to include all the possible outliers. That is why when it comes to law the interpreters consider not only the letter of the law (as it is written), but also the spirit of the law (as it is implied). For that reason all the work and documents that leads to making a new law is also considered during the interpretations in court. And when an outlier case is tested in court, that becomes a precedent for the future interpretations of the law.
@@Stratosarge I don't mean having a special rule for every possible outlier. I mean looking at outliers and seeing if, say, the categories the law puts people in actually make sense. For example, I don't need to know about every possible intersex condition to figure out that trying to absolutely separate people into men and women will lead to problems, and therefore I should probably figure out some better solution.
This is great at relating the complete interrelatedness of all life on earth. Essentially all descendants of the original organism, still technically part of an ongoing chain of splitting cells that's still going on after billions of years. Life is a soup more than a stew.
Some say viruses and nanobes are also related to us through a pre-cellular ancestor.
Not so sure about the original organism thing. unless a single rare catalyst arrived at some point, my understanding is it took billions of individual processes over milliones of years with an even bigger number of prototypes mixing and matching
I’ve watched pretty much all your videos and never have I once skipped the into animation. It slaps.
We can be sure of one thing, "species" is a categorization that has been created by man to distinguish and classify the various lifeforms found on earth. It is not necessarily set in stone as future discoveries may redefine the boundaries of what a "species" means.
However, no matter what, the categorization known as "species" is (and will likely always be) far more precise and detailed, not to mention accurate...than a "baramin".
The main thing that makes it pretty "easy" to sort most animals into different species is that most connections between the different species we recognize were so kind as to go ahead and all die, thus removing the inconvenient gray area in which we wouldve needed to draw that arbitrary line, and leaving us with just the pretty conveniently black and white ends that we can usually tell apart fairly easily.
For now...
Videos like this is why I'm so glad I found your channel.
I always play your videos twice because I love your intro and outro theme.
I'm reminded of the famous quote "all models are wrong but some models are useful".
Species _can_ be difficult to define because interfertility does not abruptly end at a specific point in a gradient of genomic incongruity, but the fuzziness of a boundary does not demonstrate the nonexistence of that boundary; on the contrary, only existent boundaries can be fuzzy.
I really enjoyed this, it's a topic I think about a lot and it was great to see your take on it. Plus I loved the new animation (or at least animation I hadn't seen before).
Yes. This is also what is meant by non-dualism, and it is (scientifically speaking) totally rad. It's quite inspiring to see these concepts brought to bear on scientific thinking. Thank you!
This is similar to the problem in linguistics of distinguishing languages from dialects. Linguists can't agree on how different two dialects need to be to be different languages as opposed to dialects of the same language - there's even a version of "ring species" called "dialect continuum".
I’m glad you are stating this because I knew this from biology but wasn’t understanding it completely until I read Darwin’s book, and realized a hard stop would disprove Darwin.
Do you have time to explain what is meant by "hard stop"?
This broke my brain as a kid. My donkey and horse had a baby and I like lost my mind. Thank you for making it make sense - because it doesn't make sense!
What a wonderful treatment of a difficult concept. This should be required viewing for all students of biology!
just to add to the breeding line of species: there are individuals of a "species" that are unable to reproduce or dont get to reproduce or maybe choose not to. the breeding requirement would exclude them from any species.
I am incredibly pleased to see you make a video where you spell this out so succinctly...
I suspect that most people with a science background already understand this... but that many who lack a science background do not.
It has always seemed obvious to me that many things actually consist of a gradient... and "speciation" is an obvious example of exactly that.
(And that we humans often assign labels to specific points along that gradient merely for our convenience...)
Gene lines continually diverge... one or two mutations at a time... so every individual is at least slightly different from every other.
Therefore any criterion we choose to use to define a dividing line between species is bound to be somewhat arbitrary...
But it is equally obvious that we need to assign some sort of labels to various points to facilitate meaningful discussions and comparisons...
However an awful lot of people seem to lose track of the fact that the labels are just... labels... much as, in physics, models are just models...
And this is obviously why so many creationists have such difficulty understanding evolution...
The point isn't what they've chosen to describe as "kinds"... or what distinctions they actually choose to assign.
The more basic problem is that they are literally unable to grasp the idea that there are gradients involved...
They insist on treating the labels as "absolute separate things"... then cannot comprehend that "there are points on the line between the labels".
It's somewhat obvious when you note how they phrase things:
They always say "you've never seen a this become a that"...
Rather than "you've never seen something HALFWAY BETWEEN this and that"...
Without the concept of a gradient they simply cannot properly visualize the concept of "in between"... as being a point somewhere along a continuum.
I suspect that it might make the subject more accessible to those without a science background if we carefully spell out what definition we're using.
Or perhaps even forego using the labels in some instances... and simply instead use visual images to show the progression along the gradient.
(In some vague colloquial sense assigning individual names to things tends to reinforce the notion that they are distinct and different rather than part of one continuum.)
Read up on Max Weber's "Ideal type". Its very helpful to understand that the terms we make up to describe complex realites shouldnt exist to put reality into little seperated boxes, but they are as an ideal type useful, so we can describe reality very closely if we compare the messy reality to an ideal type. Sure, its primarely for sociology or history, but a lot of things in natural sciences are so gradient and complex that it seems to me often useful there as well to imagine certain terms not as box labels, but as ideal types we could compare reality to. Always be aware that the end goal is not to assign certain terms to parts of our reality, but that these terms are just made up as a little tool to easier and better describe reality.
@@pi172
I absolutely agree...
The problems arise when people start "mistaking the model for the territory" (to use Korzybski's terminology).
And, in the case of creationists, they then use that error to justify claims that the knowledge underlying the model is incorrect.
(Once you assign a name you then introduce the possibility that someone will claim you did it wrong... or in the wrong place... )
It is only the fact that we have assigned names to specific points in the continuum that enables them to claim that "one has never turned into another".
I absolutely agree that it is both necessary and useful to do so... but maybe we need to explain it better.
For example a typical creationist will say... "you've never seen a little shrew-like creature turn int a man"...
The best response, which refutes this claim, is that yes both are simply points along a continuum...
And that both are simply the labels that we've ASSIGNED to points along that continuous transition from one to the other...
And so, yes, in fact, we HAVE seen one change into the other... and the demonstration of that is to look at all of the points in between...
(We say that from time to time... but perhaps not emphatically enough or often enough to sink in.)
To put that another way, for modern viewers, we should replace that "march of evolution" graphic with an animation showing a gradual continuous progression...
(That would probably convey the idea much more effectively today... and eliminate any tendency to view the process as discrete steps.)
She's fantastic!..She doesn't go after the people that obviously don't have the background, she explains..She lets who she's debating set the rules of conduct..like she says..its fun...You could have saved yourself and your readers some time by saying..."If we teach people the scientific process , those with a limited scientific background would have the tool they need to research the info themselves...or turn them on to Feynman's words "It doesn't matter how beautiful your hypothesis is, it doesn't matter how smart you are. If it disagrees with experiment, it's wrong." - Richard Feynman..
@@keithlevkoff8579 There are two problems. One is that an animation is better than a static picture - see the animation at the start of most of Erica's videos, which does exactly that! But second is, it's not a linear progression, it's a tree. That's much harder to show.
Wwooooohhhioooo variation breaks my sciences oh Noe’s?!?!?’ Y’all need to go back to school lol.
9:05 My solution to this ring species problem: Allow organisms to belong to multiple species.
Lizards A and B can share a species classification; Lizardus imaginaro
Lizards B and C can share a species classification; Lizardus examplifico
Lizard B belongs to both species. Lizards A and C do not.
Oops they were salamanders in the example :)
I like your play on words. "imaginaro" and "examplifico" lol, that's a nice touch.
this is anticipated in the Linnaean hierarchy, subspecies, species, subgenus, genus etc.
@@billjohnson9472 Yeah, but they're not talking a hierarchical system, but something weirder.
We use calendars and clocks to subdivide and differentiate one moment from another, but...while time is real...our demarcation (1) is man-made and (2) has variable results due to relativity.
As pertains to the conversation about species, discerning a fish from a bird is as easy as discerning Summer from Winter (outside the tropics), but discerning two different _Species_ of bird within the same Genus may be as difficult as telling the difference between two different Winter _minutes._
From the perspective of deep time, "living things" are a continuous line. So when we define a species it has to be defined by a given period of time. A species is a group of interbreeding individuals defined by time and geographic location. A species is an artificial designation of convenience, similar to grouping organs into "organ systems" when studying anatomy (since systems don't really exist). Just because we have a word for something doesn't mean it physically exists; it might simply be a "fuzzy" concept.
An important thing for people to realize is taxonomy isn't a science. Despite what some dictionaries say taxonomy is actually just a system of classification. A system of classification that uses physical differences, genetic differences and in most cases arbitrary human opinion to decide which populations of organisms are different from others.
Its humans trying to draw lines in the very messy, interconnected, billions year old story that is life on Earth.
Well, it's an organizational tool that is trying to reflect a reality, because you can't define things as entire gradients.
@@whatabouttheearth It's very similar to what librarians do when trying to organize books. Genres are constructs in the same way species are - if anything, they are even fuzzier because books don't really evolve.
@@KaiHenningsen
Right, but a differentiation of genetics does actually happen. A fuzzy attempt to categorize a certain area of demarcation is not not reflecting a reality. Just because I try to categorize mile markers between 155 and 355 when 155 is after a certain off ramp and the entire road is a gradient of sorts leading from one inch to the other, from mile marker 1 to 100,000 does not mean that that construct of spatial categorization isn't an attempt at reflecting a measurement of the real. A signifier is still a real refference to the signified even though it falls short in describing the signified.
To put it simplistically, closer to a nodal point of speciation divergent two lines can still interbreed fertile offspring, the more distant they become they can only breed infertile offspring, and there is an overlap between those two zones of separation, eventually with even further distance the two lines can no longer breed offspring at all. So something is happening and that thing we categorize as a divergence of species.
To try to make our categories and constructs more accurate is one thing, but to act like they are illegitimate because they are constructs, human made organizational tools, feels akin to self defeating post modernism or something. It's akin to acting like measurements on a ruler are not "real", you need to try to work with something.
Species come from ancestral lines, so it is not as confused as book genres. There is a real ancestor/descendant relationship in biodiversity. Nature doesn't take something genetic from five genera, families or orders distant cousins away, but that is what happens in genres of art. There is a real, historically objective and tangible genetic descendant relationship in nature (not counting microscopic shit because they're freaking bizzare)
@@whatabouttheearth its interesting you bring up mile markers because reflects a problem with taxonomy. There is no standardization at all (and I don't know if there could be). Every group of taxonomist has their own criteria for what is a species/genus and what isn't.
Ornithologist separate some bird species by solely by call, herpetologist lump all monitor lizards into the genus Varanus (other group of zoologist probably would have that made into 5-20 separate genus), 'Spirit Bears' get their own subspecies of American black bear despite only having their color due to a recessive gene.
When you get past genus and sometimes family it kind of becomes a free for all.
The reproduction rules for species seem to work well for mammals but fail in many ways for reptiles, fish and plants. All pythons can reproduce, and make offspring capable of making F2 hybrids. American paddlefish and Russian sturgeon can hybridize despite diverging in the Jurassic.
@@caseycannon1038
Yeah, I can see how standard for defining a species should maybe change for various levels like kingdom. As is always said "nature does not like to be pigeon holed"
😂 Shit, all I want is for animal and botany taxonomists to have the same prefixes for basic classification levels like genus, family and order. Taxonomy is never ending new vocabulary, there's Latin, Greek, Chinese, English, Japanese, South African, Patronyms and god knows what else
Let’s just say a species is a group of genetically and behaviorally distinct animals which also fill a different role than other species (ie; Different geographically, different niches, etc)
Erika, this was a great presentation of the "species problem." Thank you!
Excellent! As a avid fish hobbyist I have been super frustrated with species definition for years and always felt it was crazy to try to impose such an arbitrary rigid definition upon something that was clearly a gradient. I did not know of all the competing models out there. I learn so much from watching your videos!
This was an excellent video! As a layperson, I was able to understand on most of the surface level what you were discussing. I have an interest in the many branches of science and watching your videos has inspired me to take an academic approach in the field again. Thank you for everything you do here.
I love your intro, it's my favorite intro of all the content I consume is the youtuberverse.
Turns out I am going to miss this live but will watch it very much a must watch
It's a problem because we want "species" to be an equivalence relation. That's an idea from mathematics. The definition goes like this: You've got a set of objects, and for any two objects, call them a and b, it might be true that a~b, read "a is equivalent to b." Or it might not be true. But ~ is an equivalence relation if it follows these rules:
1) It's reflexive. This means that for any object a, a~a.
2) It's symmetric. This means that for any two objects a and b, if a~b then b~a.
3) It's transitive. This means that for any three objects a, b, and c, if a~b and b~c, then a~c.
Okay, so what if we look at the set of organisms, and ~ indicates that two organisms are part of the same species? Well, ~ is clearly reflexive and symmetric. I don't think we run into any circumstances where it's a problem to say that a creature is the same species as itself, or where creature a is the same species as creature b, but not the other way around. However, we do run into problems with transitivity. What I'm wondering is whether there's a definition for species that works in every respect, aside from not being transitive.
Isn't this why we use the clade system now and not the kingdom, family, etc taxonomy I learned in elementary school. I am just a hair older than rocks, so I hope we have learned a lot since then.
Not that I mind a good smeckledorphing, but you make me feel cheap and easy.
I am quite comfortable with the concept of species. Since nobody is comfortable dealing with deep time and the continuum of life over billion of years, the species concept gives us common ground to discuss a population, existing currently or extinct. I like. It to pulling a few individual frames out of a movie. The still are not as rich as the movie but still useful.
At 12:04 you made me yell at my phone. Putting an ad break there was inspired.
I didn't know that ligers could reproduce. I always thought they were sterile like the mule. Here's something I just read:
"The fertility of hybrid big cat females is well documented across a number of different hybrids. This is in accordance with Haldane's rule: in hybrids of animals whose sex is determined by sex chromosomes, if one of the two sexes is absent, rare or sterile, it will be the heterogametic sex. Male ligers are consequently sterile, while female ligers are not."
Like most things in the natural world, it's fuzzy around the edges. Nature just doesn't work in the paradigms humans create to make thinking easier. In short, it's complicated.
Fabulous video! Thanks!
I like YOUR definition: A static description of individuals and groups that are part of a dynamic process. That gives science the leeway it might need to change a destination when nessisery.
I love this channel more each time I watch
"static concepts ... dynamic process" I think you're right, like an idea more comfort than durable concept
I've always thought of "Species" as a combination of the two concepts, morphology and genetic relation. Always keeping in mind that reality is more complicated that the labels we use to describe it.
Philosophy of science seems really important, surprised more people don't talk about it more often. This type of stuff is generally dipping into Metaphysics, and to (some) philosophers wouldn't be very controversial. There should be more overlap more often, would make for more interesting conversations.
Yeah, up with Wittgenstein, down with Plato!
There was a Brain Scoop episodes about Grey wolves that kinda talked about this. Turns out coyotes and grey wolves can have hybrid offspring that can reproduce. Now this becomes a problem because grey wolves are protected under the endangered species act. So how much coyote genetics need to be in a grey wolf before it is no longer considered grey wolf and protected?
Wonderful video.
Very thought provoking.
Thanks Erika
This was enlightening. So species is a human construct, like race and "kind" are. That fact is also useful in itself.
Except that there are parameters that can be used to determine race or species. There is no definition at all of kind
Species are in fact widely considered “real”. In fact many would view species as the ONLY real taxonomic rank. Species are independently evolving population lineages with unique combinations of coadapted genes. Because species are the result of a historical process and as such they will be difficult to delimit early in their divergence. The same could be said for any biological entity emerging from a contingent historical process. We don’t say children and adults aren’t real biologically meaningful categories just because they are a product of development. Don’t conflate species concepts with species delimitation. Species are in fact real evolutionary and population entities.
I think there is another way to fix this process by creating two new categories of Subspecies
1. Domain
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus
8. Species-Can reproduce
9. Breed-Major Physical Differences due to geological range
10.Variant-A group of individuals with small inherited physical differences (Color, Smell, Digestion, Immune System)
11. Individual
Obviously, it reduces to "a population that biologists agree to call a species", which of course is unsatisfactory. But language is full of such terms. Just because it's not absolute doesn't mean it's not useful. Heck, it's true of "life" itself! Just recognize that fact and go on, I say.
Well, the issue is, that biologists cannot agree to one single definition, this is what the species problem is about. Each one of the proposed definitions is demonstrably wrong in some cases.
This obviously can lead to communication issues, it can lead to wrong conclusions, which is not a major issue for most of us, but it can be for biologists.
So it is important to know, that species cannot be defined in a consistent way, and understand the limitations of each definition.
I can agree to the conclusion, recognize the issue and go on :)
"Just because it's not absolute doesn't mean it's not useful." What a world we would be living in if apologists could understand this...
@@lukel1724 A lot of 'em probably do understand it-and know it's a danger to their jobs.
Excellent presentation….and Hit Monkey t-shirt. I love how it is topical, subtle and obscure.
We talk about this a lot in music theory. There are a lot of concepts in music that describe systematically what sounds good and proper to a certain audience, and which are useful for communicating about music and as tools for composing music.
But people try and apply a certain set of these, especially European music concepts, as if they were absolute rules that apply to all music at all times. Which is absolutely futile and leads to many of the same frustrating conversations as attempting to unify species concept.
As a music history/literature major with a minor in anthropology (my field was ethnomusicology), I must give you MAJOR credit for this post. You're probably the first person on UA-cam to recognize the value in music theory, as well as the problems inherent in applying the rules of the common practice period (roughly 1500-1880 if I remember correctly after 17 years being out-of-practice) to situations in which they are clearly incapable of being used meaningfully.
In fact, check out the score for Penderecki's "Threnody for the Victims of Hiroshima", some Ligeti piano studies, OR basically anything by Karlheinz Stockhausen. They had to come up with entirely new notation systems.
Also, ethnomusicologists have been doing this since the field was born (~1930, but not officially until ~1950). I remember being given a cassette tape of Ethiopian liturgical chant; the other ethno student and I were given TWO days to transcribe at least three minutes of it.
(1) My MUHL/ethnomusicology professor trained us in South Indian Hindu temple percussion; I think I'm pretty good at sniffing out rhythms and meters. I could NOT figure out the rhythmic cycle (time signature) for this piece) because every evenly-spaced pulse was going about ~25 BPM. Punctuated with a seemingly-random blast from a low-pitched drum.
ANSWER: It was in a seven beat cycle, about 50 BPM.
(2) It was completely monophonic. The closest pitches I could assign to the first two syllables were B-natural, E-natural, but they weren't using our tuning system; I could hear quarter-tones and even the central pitches were not perfectly in tune with E = ~330 Hz. Then, insult + injury: All of the pitches were connected; the singers glided from one pitch to the next.
ANSWER: Using standard staff paper, I tentatively transcribed the piece in E minor, and used a calligraphy pen's thin-to-thick writing style to show the glides. Because I couldn't nail the meter, I carefully penciled in dotted bar lines at even intervals, each representing 1 second.
I got an A for stealing from Penderecki both in my pitch notation style and my "timed" bar lines. I openly admitted to stealing the ideas and he said "If it works, use it, yeah?". My buddy got an A because he cracked the "meter" problem by taking the tape and speeding it up something like 3x. But he didn't provide any notation. Instead -- I shit you not -- his presentation on notation was to have us listen to the song "Brain Crack" by Tracy Bonham to give us an idea of how he felt for 2 days (available here: /watch?v=2SI_c78BbME
@@LJO_Hurts_Pianos I'm hardly saying anything Adam Neely hasn't said in his videos
@@georgeparkins777 Can't hide from the fact that I still agree with you. No need to be ashamed or frightened. :0)
This made me glad that people lots smarter than me are going to sort it out. What a great explanation of the advantages and disadvantages of our system-now I know lots more. Thanks.
We fondly dedicate the following poem to this video of yours. The poem is titled "Theogony":
Nothing is real,
Above the empirical seal;
Systems and superorganisms as well,
All in the depths of hell;
The constants and patterns to know,
They all lie below.
A biologist, a creationist, and I walk into a bar...
The biologist orders a Bud and a Michelob, mixes them, takes a taste, makes a face, and proclaims: "These are different and demonstrably do not mix well by way of statistical data suggesting very few proceed to do what I just did."
The creationist orders a Guinness draught and a Guinness blonde and proclaims, "I do not mix beer of different kinds."
I order a Lowenbräu and a Meisterbräu, mix them, take a drink, and proclaim, "Unibräu!"
"-bräu", not "-braü", though.
Accept that reality is continuous, any attempt to make it discrete will result in fuzzy boundaries. Species, mountains, oceans, continents, planets, national boundaries, cultures, languages, sexuality, etc.
It’s like trying to make flat maps of the earth. Useful, but inherently limited.
Interesting and entertaining program! Thank you. I hadn’t realized that there is a species‘problem’.
Species, as per my take:
A specific contempory genetic branch of organisms that are distinct in various ways enough to be catalogued in a manner useful for human analysis.
@Stirgid Lanathiel I think the idea of a hard line is the inherent problem.
Perhaps maybe "A group of contempory organisms, sharing genealogical ties through sexual or asexual reproduction, that are often perceivably distinct and share a spectrum of physical and genetic characteristics sufficient enough that a majority of specialists would agree to it being worth categorizing for reference and cultural edification."
"Contempory" was always the key word there though. The spectrum blurring the further in either direction you go between the individual's generations. Would make a lot of sense to include the year along with the traditional species name.
Homo Sapiens Sapiens 1900, or the like.
@Stirgid Lanathiel That was my point about contempories, that erases the fuzzy edges almost entirely. The fuzziness that remains is purely one about chronology, and that goes for everything from families to fundamental physics. Do families not exist? Species, families and all these things are definitely a chronological spectrum.
The closer we look at absolutely anyhting, the fuzzier it gets. What are fundamental particles made of? What are waves made of? What is space-time made of?
Everything is a spectrum that we place things on, being surprised that species are a spectrum as well is naive. At least with species we have a clear understanding of where that spectrum stretches.
@Stirgid Lanathiel My point is embracing that these things exist on a chronological spectrum.
Zoom in and there is and individual person, zoom in closer and we have individual organs, zoom in closer and we have cells and the interacting micro-biome.
Zoom out though and an individual person becomes a unit consisting of two biological parents. Zoom out again and you'll have a larger unit, and so on until we are both contained within the same unit.
Having looked into this further, I guess you can say I'm a proponent of the genealogical concept of species.
Another commenter named "Les Freres de la Quote" made a beautiful comparison to language and the concept that perhaps it would be better to think in terms of how much energy, or in my case how many familial steps, it takes to define the concept.
You are right though, and it's my opinion that embracing the fuzziness as an intrinsic part of reality still allows for proper categories. After all, it is humans that will decide how wide of the spectrum they will encompass within any single unit or category.
Just like I learned in my Bio Anthro courses.
Great stuff Erica!
This is one of the biggest issues I had at uni when learning about all these concepts.
Glad to see you recovered from losing all your neck vertebrae in the thumbnail!
A good example of how Mayr's definition fails is seen in two fish commonly kept in home aquariums.
- Xiphophorus maculatus (southern platyfish)
- Xiphophorus hellerii (green swordtail)
Same Genus, but different species.
These two can readily mate and produce viable (non-sterile) offspring.
Furthermore, if Spock is not sterile, then humans and Vulcans are the same species (by Mayr's definition).
Spock: come on baby, do it for science!
Thank you for this. That very question has been bugging me for a while. I'm not the only one after all.
Thank you very much. We don't have to listen to people crying about the extinction of "species" and paving over the wetlands anymore.
Bless you. You are doing the humane work of educating ppl on this. It's a thankless task.
The problem was succinctly stated by Einstein as thus, " As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.”
More generally, "As far as the models of science refer to reality, they are not
certain; and as far as they are certain, they do not refer to reality.”
There was a famous experiment regarding this conducted by Richard Feyman. He changed freshman Physics at Caltech from Newtonian to General relativity. And failed.
What's going on here? Well, to the extent that a model can be used to control and manipulate the world through engineering and manufacturing, the model is useful. General Relativity is a more precise model than Newtonian physics but most of the time all you need is Newtonian physics.
Models will always be imprecise. The standard for which imprecise model to use is strictly practical. If 99% of modern medicine can be implemented using reproductive specie definition then get on with it. Finally "real" as used in this video is unhelpful. Someone once noted that the use of the word "real" is the only word that should always be used in air quotes. A better question is which definition of the word species has the most applicability in building models for engineering and manufacturing, especially in medicine. Once one gets over the concept of precision then one can settle in on application. Yes, there is no universal definition of "specie" that can support all models. But if there is one that gets the job done for most models it should win the day as the unqualified word and then all other models qualify the word specie to import a different definition required for the model.
One minor point - "species" is both the singular and plural here. Once you start talking about "specie" you are actually discussing coinage, not biology.
Both beautiful & brilliant - wow, wow...!
I think the term "species" applies best to current day things, something we right now would consider separate from another thing. Like with people albeit much less varied than all of animalkind. Looking for various ways to separate ourselves from each other when in reality we're all distant relatives. But for us and how we defined the family, calling everyone a distant relative as opposed to brother, sister, cousin, father, mother, friend, stranger, etc. would kinda kill any way to classify each other in that more specific manner
I work in parrot rescue and we are constantly confronted with the inadequacy of the biological species concept. Sun/Jenday/Goldcap conures are a line species, while the famous Wild Parrots of Telegraph Hill (the birds I work with) are a fertile hybrid of Mitred (Psittacara mitratus) and Cherry-headed or Red-masked (Psittacara erythrogenys) conures.
Before the genomic restructure of the Psittacidae family, it was even possible to hybridize across genus boundaries, tho these cases were mostly restricted to forced pairing by evil parrot breeders.
I am absolutely going to show this video to my Bio class. Thank you Erica for the interesting and thought provoking content
It’s great to see young people discover and rediscover the limits of categories. This is not limited to species of course. The journey leads eventually to the emergence of order in self-organizing systems through synergetic thermodynamics.
There has always been order in the universe.
Or there has always been chaos in our universe.
Whichever or use another word, it is just semantics and humas trying to catagorise things
@@josmith9662 True. Although I have to admit that the process of categorizing things is quite important for mobile life - because orientation/navigation needs categories to create patterns for decision-making. It's not trivial at all.
I love your videos that are just about biology. I think you have a really good mix of content right now!
A species is just a snapshot in time of a lineage as it continues to adapt to existence in its situation.
A snapshot based on generalizations, averages, and ranges, and using different lenses (aka definitions). What is a man (besides a miserable pile of secrets)? Like what characteristics make a human? Size is incredibly variable: from the smallest born human to the largest who ever lived. Body plan? You can be born missing limbs or have extra. Even missing parts of your brain. Genetics should be fairly definite though? Not unless you want to argue that people with Down, Cri-du-Chat, or Turner Syndrome are somehow less/inhuman.
Species as a concept is definitely useful, but it cannot be usefully defined in a way that doesn't lend itself to many exceptions, even in the context of just being a snapshot in time.
This isn't me arguing against what you wrote, but moreso expounding my own thoughts in relation to it.
I really like that colour gradient as a means of showing how hard it is it pin down a "species".
This is so good. I totally get that GG's approach takes a naturalistic approach but there is an important - even vital - "moral" implication here. I think it is a very good thing indeed that we be constantly reminded of our place in the universe ... it is not central! Being part of life's flow is value enough - or should be - but for various reasons we find this hard to accept.
I'm doing my honours in evolutionary biology right now and this is something that directly relates to my project. It's tantalising but frustrating how species are ultimately arbitrary but also so useful.
I love how nature doesn’t care about what seems sensible to us humans.
You have to also throw in that hybridisation is often the starting point for periods of speciation, and that horizontal gene transfer often happens between just about any living thing regardless of species. Big leaps in evolution often happen when novel genes are transferred. For example a key protein for the development of the placenta likely arrived via a virus. I prefer to think of species as being like pools of water or oceans, interconnected by rivers and channels of varying flow rates, constantly merging and separating over time.
I thought Ligers were infertile. But I am no expert... I do know of many successful hybrid snakes, since the wife and I delved into Ball Pythons and their breeding... I have seen Australian and African pythons hybridized... Not sure about the reproductive viability of the offspring... But Borneo Bateaters (Burmese x Retics) are viable, Burm Balls (Ball Python x Burmese) are readily available for purchase...
It astounds me how you can equate ligers to hybrid snakes. Snakes are snakes. Do I need to repeat that for you? Snakes are snakes. They should literally all be able to breed amongst themselves freely.
Tigers are not lions.
@@harryosborne8215 I wasn't equating anything. I was making an observation. A Ball Python isn't a Carpet Python, they are in a different genus.
I have not seen any hybrids of say Colubrid to Python, crossing different families.
Lions and tigers are in the same genus. So I really don't see your point.
@@dracdrum Only male ligers are sterile in accordance to Haldane's rule. The reason male hybrids are usually more likely to be sterile compared to their female counterparts is because males have two different sex chromosomes.
Here we come
Walking down the street
Get the funniest looks from everyone we meet!
HEY HEY WE'RE THE HUMANS
AND PEOPLE SAY WE'RE HUMAN AROUND.....
Glad to see that astronomy isn't the only field of science dealing with this (classification systems for celestial bodies fall flat each time a new discovery is made).
Brazil faces this same problem. could you make a video talking about creationists in politics and medicine and music etc in the USA. and please subtitle it in portuguese would help America a lot. and you would have a lot of visualization. if you can put it in spanish too
if one day you can put English subtitles on the videos you consider most important to society. I would really appreciate it
Thumbs up. Very interesting indeed, and I guess... yeah... nature doesn't care about our need to categorize. It's nice enough to know we are connected to all life.
The sheep and goats must be particularly frustrating for creationist taxonomists...
I mean, humans mate with all kinds of animals. Especially in distant rural areas.
Sadly true but more so in the South . Animals in the north are colder and crisp and more alert.
Leave the Welsh out of this.
I live in a remote rural area and I resent your insinuation. Please never address me or my wife, Mrs. Horse, ever again.