How Do We Figure Out The Sex ... Of A Fossil?
Вставка
- Опубліковано 23 кві 2024
- We know a lot about fossils, but there's one thing about all those long-dead organisms that's hard to figure out -- their sex. So let's talk about the ways we can try to determine whether those T. rex bones came from a male or a female, and why figuring it out is so interesting!
Correction:
02:23 While female peafowl are more drab than males, the bird pictured here is an entirely different species: a helmeted guineafowl.
Hosted by: Reid Reimers (he/him)
----------
Support SciShow by becoming a patron on Patreon: / scishow
----------
Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever: Adam Brainard, Alex Hackman, Ash, Benjamin Carleski, Bryan Cloer, charles george, Chris Mackey, Chris Peters, Christoph Schwanke, Christopher R Boucher, DrakoEsper, Eric Jensen, Friso, Garrett Galloway, Harrison Mills, J. Copen, Jaap Westera, Jason A Saslow, Jeffrey Mckishen, Jeremy Mattern, Kenny Wilson, Kevin Bealer, Kevin Knupp, Lyndsay Brown, Matt Curls, Michelle Dove, Piya Shedden, Rizwan Kassim, Sam Lutfi
----------
Looking for SciShow elsewhere on the internet?
SciShow Tangents Podcast: scishow-tangents.simplecast.com/
TikTok: / scishow
Twitter: / scishow
Instagram: / thescishow
Facebook: / scishow
#SciShow #science #education #learning #complexly
----------
Sources:
www.nasa.gov/vision/earth/loo...
www.journals.uchicago.edu/doi...
www.usgs.gov/publications/cas...
• Learn how Supervolcano...
www.sciencedirect.com/science...
agupubs.onlinelibrary.wiley.c...
agupubs.onlinelibrary.wiley.c...
www.researchgate.net/publicat...
www.sciencedaily.com/releases...
www.usgs.gov/programs/landsli...
www.journals.uchicago.edu/doi...
www.jstor.org/stable/27851899
www.usgs.gov/observatories/yv...
www.jstor.org/stable/10.1086/...
geology.utah.gov/map-pub/surv...
pubs.geoscienceworld.org/gsa/...
www.kent.edu/research/landsli...
geology.utah.gov/map-pub/surv...
agupubs.onlinelibrary.wiley.c...
theconversation.com/mars-we-m...
www.science.org/content/artic...
Image Sources:
www.gettyimages.com/detail/vi...
www.gettyimages.com/detail/vi...
www.gettyimages.com/detail/vi...
commons.wikimedia.org/wiki/Fi...
www.gettyimages.com/detail/vi...
www.gettyimages.com/detail/vi...
www.gettyimages.com/detail/vi...
www.gettyimages.com/detail/vi...
www.gettyimages.com/detail/vi...
www.gettyimages.com/detail/vi...
commons.wikimedia.org/wiki/Fi...
commons.wikimedia.org/wiki/Fi...
www.gettyimages.com/detail/vi...
commons.wikimedia.org/wiki/Fi...
commons.wikimedia.org/wiki/Fi...
www.gettyimages.com/detail/vi...
www.loc.gov/resource/highsm.4...
link.springer.com/article/10....
www.gettyimages.com/detail/ph...
Oops! That's not a female peafowl at 2:23. Females are more drab than males, but the bird pictured is an entirely different species! Thanks to everyone who pointed this out. And, for the curious, female peafowl look like this: commons.wikimedia.org/wiki/File:Female_peafowl.jpg
SciShow totally left out the B-Rex story. Shame Shame Shame 😢
@LookatRealNumberesthe peacocks use their train feathers primarily to show off to the ladies. They will 'lek' or find a spot to display, then wait for the females to decide whether they like the show. Peacocks can fly, quite well, and when they have a full train, it doesn't slow them down much. They shed the train feathers each year after the breeding season and grow a new, often even more impressive, set of feathers for the next year.
Source: I have owned peafowl for almost six years. I have three peacocks and two peahens. They are currently in full Disco Turkey mode and showing off constantly 😂🦚❤
Thank goodness y’all’d already addressed that little bloop lol
Correct, the one in foreground is a Guineafowl. Most likely a hen, but there was not enough footage.
I should’ve looked at the comment sooner. Yes that is the wrong animal. Thank you for addressing this look at mine. That is a guinea fowl.
Paleontologist determined that the Yucatan asteroid was a gender reveal party gone terribly wrong.
AKA business as usual, for gender reveal parties.
Yeah, sad but true! 🎉
God was like:
“if this asteroid hits the blue planet (earth) it’s gonna be a boy, if it hits the red planet (mars)it’s gonna be a girl”
*roughly 65 million years later*
Out pops Jesus
@@thestic6349don't know whether to laugh or cry 😅
best one yet.
I teach junior high. I hang around way too many 13 year olds not to make a petrified wood joke.
Are you an adult? Shouldn't be too hard really.
@@timstone2813holy crap why is everyone hating in the comments, lighten up, have some fun, jerk
@@UnlistedStory no, i don't think I'll lighten up to the forced agitprop.
Hey, sometimes, you just need a laugh, no matter how infantile the joke X-D
@@timstone2813Being an adult doesn’t have to entail being a wet blanket.
Sue the T Rex
Why would I want to sue the T rex? What crime did it commit?
It ate the lawyer, so obviously it's getting sued. 😂
They killed my neighbours cousins best friends step mother, actually!
Eating random pedestrians 65 million years ago
Tax evasion
as @@ODISethsaid they haven’t paid taxes in hundreds of millions of years
Easy. All the dinosaurs in the park are female.
Life... ah... finds a way.
Alan
Life finds a way
wow i bet the comments on this video will be super normal
Okay, you got me!
(but not before I'd whipped off 2 sophomoric comments...)
Lol their years-old gender spectrum video is a nightmare in the comments. so I'm sure we can all be civil about dinosaurs.... riiight?
Seems like it's just full of people pretending to get upset sarcasticly
@@kevinb9830
We will be fine. Unless were in an American college or university.
@@kevinb9830
Can we agree sex and gender are not the same?
I thought the title said “how did we figure out sex …with a fossil?” And I thought I was going into a very different video
It’s like going to the bone zone
to be fair you'd be astounded at how many different things and how often doctors have to remove things from holes they shouldn't be in, with how people are i can 100% see someone sticking a bone up there.
And you still clicjed on the video? 😂
@@lardgedarkrooster6371 hey man, fossils are sexy.
@@TheDurk 🤣🤣🤣
3:31 You guys wouldn't mind doing a video on why and when humans lost their fangs? From a quick search there aren't many videos going over it in detail
Hard to know - we'd have to find the infinitely unobtainable "missing link", first. It seems that whenever a "missing link" species is discovered, it inspires the search for another one, because not enough is similar. Make of that what you will, y'all :-)
The earliest hominids already lacked the C/P3 honing complex, which is what keeps the canines sharp in all other modern great apes.
Ooh might be a question for Gutsick Gibbon?
our ancestors probably lost our fighting teeth when our skulls changed shape thanks to bigger brain mass gained from cooking food. we developed shoulder muscles for holding things while walking upright, throwing weapons, and swinging our fists. chimps fight with their fangs, humans fight with their fists.
@@golddragonette7795 That's the lady that debunks YEC's right?
Fun fact: In humans, you can only identify sex by bone structure about 30% of the time.
Yeah objectively incorrect lmao
Source M.A. XD In humans is way way more reliable.
Remembering there was one study that analyzed the dimorphism of a trait with a sample size of two specimens....
Oh good lord. What species were they looking at?
@@quiestinliteris I think it may have been tyrannosaurus, but it was long enough ago I'm not 100% sure.
why did my brain jump to Adam and eve lol
@@corvusmonedulaexactly
Easy. blue fossils mean boys and ....
This is going too far, even rocks have gender reveals!
From what time period? Blue was not always for boys, but I understand what you mean.
@marcopohl4875 yeah that gender reveal near Chixulub was devastating!
@@timstone2813 For example, the ancient Egyptians seem to have used green for men and yellow for women.
@@billberg1264 really? Do you by chance know why?
Shout out to all of those people saying "archeologist will know what you are when they dig your skeleton" XD.
as an archeologist... I just laugh at that 🤣
They might know by your clothing, stuff you asked to be buried with, and what your tombstone reads. Depends on what you say to do in your will.
@@CritterKeeper01 true, but that is assuming you get buried in a cemetery, if you get lost in the wild and die, somehow your bones survive and get found by archeologists 1 millon or 2 millon years later it would bot be straight forward to know what sex you where. (Assuming no DNA survived, and even then you could have a chromosomal variation)
That is the point of this, we are not sexually dimorphic enought to make that distinction clear.
Male or female, what I do know for sure is if that T-Rex was “a boy named Sue”. He had a rough life.
RIP Johnny Cash ❤
As someone who had to take Wildlife ID and learn to identify species by baculum as an undergrad, they're what I thought of as soon as I saw the title, followed by dimorphism.
I thought this was a repost and then realized I was thinking of Eons' excellent video on this subject from a couple months ago
You ask politely
2:23 Big whoopsie! The foreground bird is NOT a female peafowl. It is a helmeted guineafowl. Talk to your editor 😬
Nice spot!!
All looks the same to the editor
It's a bird, good enough for me
Bird go bird. Very smol mistake
Are you a kindergarten teacher? "Big whoopsie" and "😬" are just iconic when you're pointing out a tiny mistake.
a T rex named Sue
epic song idea
Who knew that female peafowl were guineafowl? 2:25
I mean Guinea, fowl and pea fowl.Do look very similar
I saw that and immediately went to the comments lol
Same😂 very much made me upset! Lost a little respect in scishow today
I suggest just putting it in carefully
You clearly didn’t watch that movie about the girl who had teeth down there
@@arafatsefu4239Nah bro what
I think it may be pronounced “med-yew-lary”?
I own an oosik I purchased in Anchorage in 1990. I keep it in my office, and love to hand it to people first, then tell them what it is.
Chuckle chuckle. The "female peacock" is a Guinea fowl.
Not a peahen?
@@ragnkja they mean the clip of a "female peacock" is actually depicting a bird called a Guinea fowl. Peahens look completely different from Guinea fowl.
@@jasonnehf4373
Oof, I expected better from SciShow.
@@ragnkja it's not uncommon for peacocks & guinea fowl to live around eachother in easily-photographed environments - several zoos in the US allow the birds to roam freely during the daytime.
In reality, I'm betting peahens avoid peacocks when possible - competing priorities & such - probably making it hard to find a single photo of both.
I'm guessing that the editor found a photo of a peacock & a homely-looking bird & assumed it was a peahen.
Man sometimes I wish people commenting on the internet would just shut up and read a book
Been to the Field Museum and was able to see Sue and it was neat tbh. Also bought myself a very pricey sweater with the skull on it that I do wear.
I love seeing fossils I recognize from my home city's museum in videos! My brain always goes, "Hey, I know that guy!"
so dig, dig, dig, find more fossils, now!!!
Well, there have been boys named Sue, as documented by Johnny Cash.
Super interesting!
My first thought was genetic analysis, but clearly there isn't either enough to test or enough knowledge to interpret it.
Genetic analysis of (non-avian) dinosaurs is kinda hard :( (anything over several million years old is too degraded. Even in amber)
Ice age animals we can for many specimens.
I feel like scishow did an episode. I'm going to find it!
DNA has a half life of 521 years. Under the absolute best conditions, it completely disappears after 7 million. The Jurassic Park misquote is impossible, sadly.
Do we even know if sex determination was genetic in non-avian dinosaurs? It is in birds and mammals, but not in reptiles. Plus, birds and mammals use completely different schemes for genetic sex determination. So I don't know if we have enough of a timeframe narrowed down on the emergence of that trait to say how dinosaurs worked.
and for many reptiles, sex determination isn't done by chromosomes... it's done by temperature at incubation.
@@billberg1264dinosaurs are more closely related to birds and crocodiles than they are to other reptiles. Modern crocodilians (and many turtles, and the tuatara) exhibit temperature-dependent sex determination, while modern birds exhibit genotypic sex determination (i.e. based on the genetics of the embryo). Other reptiles exhibit a mix of the two traits. So how did it work in dinosaurs? We might not ever know for certain.
Easy: Fossils are rocks, so they don't have a sex! (joking)
I've never heard anyone pronounce "medullary" the way it was said here. MED-yoo-Larry is more like what I always hear in Continuing Education talks and conferences.
What about Trixie?
I've always heard it pronounced "Med-You-Larry"
It's literally cute bird 0:06
I was originally wondering if there is any sexual dimorphism in dinosaur pelvises, since I would assume the female’s pelvis would have to accommodate the egg
Depends on the size of the egg. In a lot of species the eggs are small enough not to require extra room, unlike human babies. Human females and males have different shaped pelvises, and you can even tell if a female had a baby, since that further changes the shape in an irreversible way!
Just throw some gray sweatpants on the fossil.
Thanks!
My name is SUE! How do you do?!?!
We need Harry and Butters to check under the tail!
So... I'd like to bring up the fact that most species that do infarct have a baculum often have a the baubellum in females, but I get it we can't say clitoris on youtube but penis bone is fine.
It's tricky when a species doesn't have enough dimorphism to prevent overlap. As is the case with humans much to the chagrin of... certain types
So it could be a boy called sue? :-)
I’m going to visit Sue tomorrow ❤
I really would like to support the conclusion of these being signs of medullary bone but what about the refutes that these signs could instead be some form of bone disease causing inflammation?
I like how the singular they/them has made a resurgence when referring to a singular, unknown person whose gender is also unknown - the he/she / him/her trend that started back in the mid-20th century was clunky - the (s)he experiment during the late '90s and early aughts more so - and the experiments with "it" during the '80s always sound(ed) awkward.
I say "resurgence" because, according to the fine folks at Merriam-Webster, the singular, unknown person of unknown gender sense of they and them predates the yet more loudly defended he/she and him/her by multiple centuries in written English, likely longer in spoken. And yes, this includes "themself" ;-)
The singular They does predate the singular You, after all!
Singular they is so good for one simple reason, it has always existed and had its place in the language, people use it literally every single day without even thinking about it. I think that's why neo-pronouns are just an small internet niche and nothing else, they feel too "forced".
@@filipkohout4704Singular they HASN'T always existed; we just got used to using it. I don't use neo-pronouns for myself, but they only feel "forced" because you're not used to using them (for example, some of them have actually been around since the 1800s). Language evolves, things change, humans get used to stuff. It's really not a big deal to refer to people however they want.
@@kashiichan That "always" was a quite obviously just for a dramatic effect.
@@kashiichan I don't think It's a big deal either, I always refer to people by their prefered pronouns. I was only poitning out why singular they is subjectively better suited for most people and why neo-pronouns are not.
Thought this was a vanoss video
If Sue were female, that'd be okay, but if they were a Boy Named Sue they'd have that Johnny Cash connection
Baculum? I barely know um!
Most of this evening is probably at least because. Things could have changed since all the way back. Then that was a millions of years ago so I don't think we can know for sure.
Why not look at dinosaur soft tissue? Chances are that if we can detect phenomena like disseminated intravascular coagulation, we can find other biochemical markers to indicate the sex of a particular fossil. Msybe we'll find DNA amidst the tissue one day? Even if it is incomplete, it may tell us loads!
Yes, but truly, what is stopping me from headcannoning the dinosaurs as non-binary? The correct answer is *nothing* .
I completely agree, Sue shall forever be an enby dino icon 🖤💜🤍💛
Y'all weird
And I say this as a trans individual. Y'all really weird.
@@AcidicGothess I fail to see how being trans adds any authority to the comment you've given.
@@AcidicGothess sometimes i kinda feel like the more accepted LGBTQ+ community gets, the more desperate they get for representation or icon or whatnot. im not saying acceptance is bad, its very good progress, i just find it kind of counterintuitive...
Wait I thought Jurassic Park already did that
I can think of one way
Da best way to prove the sex of a dinosaur? Just look at dem bone.
Best comment
Hi Reid!
Who knew science could be so... bony?
Thanks for using “they/them” reasonably
Considering chickens are capable of literally changing their sex, I wouldn’t be shocked if some dinosaurs were capable of the same, just to throw more of a loop into it all.
They can?
No they cant
Chickens... Cannot do this. You might be thinking of intersex situations
@@AcidicGothess Chickens are capable of spontaneous sex reversal, though that’s not to say it’s 100% complete. You will still wind up with an extremely cockish hen, so to speak, however.
@@lefishe7702it’s not a complete change as in other animals, but they definitely can effectively change their physical body to match the other sex.
Was Sue's jaw bone broken before or after death?
So are they non-dinoary
How do we even know all dinosaurs even had definitive genders? Could some have been hermaphroditic?
Any species that have two or more sex can technically be hermaphroditic if a little genetic mishap happens. But on a species level, no, generally speaking vertebrates just don’t do that. It’s more likely that they would have asexual reproduction and just one sex rather than a species level hermaphroditism.
Simultaneous hermaphrodites are organisms that, as a species, possess both sperm organs and egg organs at the same time. This can happen in animals as well as other kinds of life, but the animals are mostly ones like snails and coral.
No known simultaneous hermaphrodites exist in Tetrapoda, the superclass that birds/dinosaurs, reptiles, amphibians, and mammals like us all belong to.
There are intersex variations, however, where an individual displays traits of both sexes (for example, an animal with both male and female coloration), found across Tetrapoda. Sometimes this includes traits of both reproductive organs, but it's not the same thing as a snail where they're both independent structures. Tetrapods have one set of reproductive organs, so the blueprint for "both at once" like a snail doesn't exist. Rather, an intersex tetrapod may have traits of both types in one set of reproductive organs. (Or not, intersex variation is complicated. Many intersex conditions in humans are completely invisible without lab equipment.)
So the answer is that we believe dinosaurs were not hermaphrodites because they were tetrapods, and we don't know of any species of tetrapod that is hermaphroditic. But we have photographic and genetic evidence that modern dinosaurs, AKA birds, are sometimes intersex. So a fossil dinosaur could totally be intersex. Unfortunately this would be almost impossible to prove.
@@aliengeo thanks for the clarification
Handy to know if there's sexual dymorphism in fossilised animals, you can then unlock how they selected mates, courtship rituals, the sex lives of dinosaurs - did a male tyrannosaur have a lovely singing voice and colourful markings, or was size the selection criteria ?
I find it amusing, that T-rex could be a boy named Sue. Makes the Cash fan in me chuckle.
So, how long organic tissue last? Thats a better question
That depends entirely on the conditions it is preserved in. Not that it really matters in the case of fossils which generally have no organic tissue left due to permineralization.
The few that do have some soft tissue preservation, were in very specific conditions and are not exactly the same as they were shortly after the animal dies. What is left is a very small amount of mostly collagen that was slightly preserved due to high iron content.
@@drewharrison6433 so thousands of years right?
@@kanzzon What part of my answer had anything like a number in it?
Potentially tens of millions of years. Mind you, it isn't anything like what it was inside the animal. It doesn't have DNA or cellular structure. It is highly modified collagen.
@@kanzzon Tens of millions of years. It's not the same as when it was in the animal. It has been highly modified by it's environment. There's no DNA. It doesn't matter anyway. Most of the information is in the rocks that used to be bones.
It can last up to several thousand years
They are always hard...
People already working hard to make this comment section full of ignorant people trying to troll. Sex and gender are 2 different things this video is about sex not gender.
Uh oh, here come the attack helicopter jokes...
Anyone who truly believes in science supports the fact of gender identity being separate from sex, so if anyone disagrees, they don’t fully understand how neuroscience and anatomy works. Simple as that.
Monogamy tends to reduce sexual Dimorphysism.
a t-rex named sue...
why is the '...' in the title needed?
To get extra comments from people who ask.
It's a comedic beat (see comedic timing).
Drama
I had a feeling the comments would be cancer
A boy named Sue?
Sure why not? Leslie, Rene, and Kelsie are unisex names.
Maybe that’s why the dinosaur died; life ain’t easy for a boy named Sue.
Since people in the comments have decided to be goobers, I might as well.
Everyone here is just a random collection of atoms that happens to move on its own rather than via outside stimuli. It doesn’t matter how those atoms are arranged in what pattern, so long as you aren’t disrupting the cohesion and stability of another self propelling atom collection for a reason beyond atomic replacement.
Materialism is moronic. Good job of smashing meat on plastic if nothing matters, you random clump of cells.
Wow. What a goober!!
But where’s your chair
Must have been an older video that they only just now published?
2:23 isnt saying "male peacock" tautological? like "cock" means male fowl, doesn't it?
Gender neutral? Well, I suppose there was that one boy named Sue...
This guy is so nice and handsome - but I really miss Mikey telling me insightful things! That was just so satisfying - but this handsome gentleman is almost enough to make up for not seeing Mikey anymore. Almost
the guy who hosted the show today (his name is Reid!) has actually been on SciShow for ten years now, there was a post about it on the SciShow community page! I’m surprised if you haven’t seen him before but that’s valid if you have not!
You didn't mention it, but don't female humans have wider hips on average, compared to males, in order to give birth?
It's actually the pelvic outlet, but yes you can tell the difference! And you can tell if the female had given birth during her life, since that further changes the shape of the pelvis. It's really cool!
@@bookworm3005that doesn’t sound cool bro. That sounds painful, why would I want my pelvis to change shape??? /j
They didn't mention it in the video because this one is about dinosaurs, but the key here is really the "average" part of that sentence - we just don't have enough fossils to work out what the average is, so there's not a lot to base conclusions on.
Keyword is heavily on average.
All the bones can do is indicate likelihood as it's something that can be changed drastically based on the hormones or activity of the person. A weightlifter of either sex will literally have an altered bone structure. as said, averages is the keyword. Error rates can go as high as getting it wrong a third of the time.
Obviously you look at it's cloaca
Bone it and find out.
As the sex cannot be defined, why give it a name?
so you cant tell without reference to current animals?
I miss 2014.
411th to comment.
🦴
note to self: only some male walruses have a bacculum.
P:)
øøøøØØØØ
you mean we can figure out sex from bones? huh... how interesting 👀
If that was your takeaway it's not shocking why you fail to understand even high school biology.
How about you don't speak on things you are uneducated on and butt out of others business.
A boy named Sue? lol
Just because it fits doesn't mean it belongs.
17
Come on guys this is scishow!!! Please do not say a guinea fowl, is a female peacock! Female peacocks are brown and do not look like that!!!! 2:26, I have respected y’all for years. Do not let me down now, By going a cheap way out on a video clip!😢
Isn't a female peacock a peahen?
You can always tell a fossils gender by “the bone” 😉
You can tell their sex. Gender and sex are scientifically separate
Eons. Your sister channel made more or less the same video about two months ago. With more or less the same information. I can't help but feel like doubling up on the same content was a waste of resources and time.
Is it a waste of resources, or is it reusing the existing script to bring that information to this channel to both inform a difference audience than those who might have watched the Eons video and generate more funds via ad revenue? If anyone watches here who didn’t watch the Eons video, which based on the comments I believe happened a fair bit, then that information is spreading to a wider audience.
@@ODISeth As I'm subbed to both channels I got little out of a second viewing of the same info. But that's just me.
Obviously if you find see a breast bone, female, but just one BIG bone... do I really have to say it?
You do know that men have breast bones too, right?
Just about everything with a rib gage had a breastbone.
@@jokercardzz And I suppose next you are gonna tell me that women can have one BIG bone, too... 😆
@@jokercardzz Actually curious - If it WAS clear that I was just kidding, then your reply makes no sense. On the other hand, if it was somehow NOT clear, was that because I forgot to add the "jk" and a winking emoji?
I confess i thought you were referring to the medullary bone so i got wooshed sorry
Wait - didn’t Mary Schweitzer discover collagen in Sue’s bones? And didn’t Mary discover that Sue’s bones prove that she was pregnant at the time of death? That proves Sue was a female T. Rex.
First that I've heard of this - where'd Ms. Schweitzer publish her findings?
@@brandongaines1731 Honestly, I don’t remember. You’ll have to look it up.
@@brandongaines1731 en.wikipedia.org/wiki/Mary_Higby_Schweitzer
No, it was a dinosaur named Bob the b-rex. Not a joke, that's what it's called
@@alyssabrown-carleton6173 Maybe I’m a bit confused Alyssa. But I know the story about Mary Schweitzer is true - it’s mentioned on her Wikipedia page.
seems like a dinosaur could be "it"
While in Mammals males tend to be larger than females, in extant dinosaurs (ie birds) it’s often the reverse. And in many species of birds it’s the male that’s the care giver.
This only applies to some birds like raptors, in fowl it's often the opposite and a lot of others don't have much if any size difference.
People really acting like gendered objects don’t exist and that sex and gender are the same smh
They're obsessed.
Lol calling an animal shaped rock them/they I though the whole idea of using that pronoun was avoiding dehumanization, but I guess y'all just dislike using "it" XD