The Crocodile's Unusual Sex-Determination System Explained
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- Опубліковано 30 вер 2017
- Crocodiles dont have sex chromosomes like most animals on earth. That means that their sex cant be determined by their genes. So what determines the sex of their offsprings then? Thats the topic of this episode of Facts in Motion.
Enjoy.
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"So what happens if you raise the temperature even higher? Does it make a male crocodile?"
"No, it's gender will be 'dead' crocodile."
The eggs would probably get too hot and the babies would die 😢
Keep at what you're doing. The effort you put into these are very apparent and it won't be long till UA-cam let's your videos be properly seen. You really do deserve more subscribers and they'll come))
What's common between Crocs, onions and ogres ?
LAYERS!!!!
I subbed ,this is quality content
SneakySneaky Snake sigh
Sigh
SneakySneaky Snake huh? Ogres have layers?
thank you
Crocodiles have gone through millions of years of climates changes. Ice ages and much higher temperature during the Mesozoic didn't stop them, so I doubt global warming will effect them much at all
True. But you have to keep in mind those changes usually happened a lot slower giving animals more time to adapt. The cooling of the planet that resulted in the Ice Age took 20 million years - not just 100 - and it still resulted in mass extinctions globally.
And that's the problematic part of this whole climate change thing. It's not only the temperature itself, it's also the rate of change that's so dangerous.
On top of that, many crocodile populations are already dangerously small bc of humans, which makes them vulnerable to rapid environmental change.
@@factsinmotion3978 It will take more than 100 years for big changes in temperature. While there is a trend of higher temperatures it wont be a dramatic change in a century. It will probably be around a couple of thousand of years which as we have seen in world history it has happened before. But the world wont get as hot as the time of the dinosaurs any time soon cause we are in an interglacial period and in a couple of thousand of years the ice age will come back with a vengeance.
@@Epsilonsama we've had a change of a couple degrees Celsius in those past 100 years. That's the issue.
I won't go into the topic if humans are responsible for it, it's pointless, however, that's a rapid rate we have going on, and the side effects are massive.
Baby crocs look so cute !
There little cries/chirps are pretty cute too!
Jimmy Weeks yeah
The Great Wolf I dare you to pick one up
Rainbow the Kitten I already did this. I also pet a full-grown croc called Hannibal. He was a gator, but gators are crocs.
The Great Wolf the Cries r as well!
baby crocs calling for thier mom is the best sound ever
Maybe because crocodiles evolved so long ago, that’s why they have no sex chromosomes. These videos are so interesting!!!
good theory. I actually didnt even look for an answer to why that is.
u are so underrated. Keep up the good work because i just found your channel and it is entertaining!
Thanks!
i wonder what evolutionary benefit this has.
Not all features of an animal need to present a specific advantage in order to develop. However I conject that the fluctuating number of the sexes during certain climate events increases the selective pressure as only the most desirable members of the over-abundant sex will reproduce. This is believed to be the evolutionary basis for sexual reproduction in the first place. Males are less likely to reproduce than females and so competition is accelerated. Useful genes will become extremely sexually desirable and rapidly spread throughout the entire species.
@@Crusader1089 Ah, I see you are a person of culture as well.. 😌🍷
4:10 "All crocodiles will soon be killed off by the Manbearpigs."
Only retards think global warming isn't real
John-117 😂😂
@Narrowc - Manbearpig is real... I was it once... it took my foot clean off...
@@Narrowcros The earth could very well be warming. But did humans destroy a planet that has survived for billions of years without somehow possessing some thermoregulating systems? Unlikely.
what he meant was that the sun is getting hotter each year, warm and ice ages are completely normal thing
Congrats you are on to a winning formula. Keep on making more of this good stuff.
Amazing channel! Please keep doing these amazing videos! Thank you.
Keep up the good work bro...i really enjoy your video very much.
I find it awesome that The Terrifying and Large Powerful Reptile is capable of being gentle and caring for the young. From now on, instead of a Mama Bear, we should compare with a Mama Croc lol
The thing is, that we tend to look at reptiles as scary animals. To be fair: large reptiles are scary as hell, they're pretty much designed to kill. They aren't exactly smart, but there's a reason why crocs have been around for millions of years without any major changes. They're one of the few families that actually lived alongside dinosaurs, I'd say they deserve credit for that
Excellent produced!
Lucky Greetings Lobo Loco
Wow I never thought of that you are making very interesting videos
thanks!
163 subs?!? WHAT?!
; ) Still fairly new channel and I'm still figuring out my animations and what topics I wanna cover.
Facts in Motion Expect more subs coming😉
thanks - let's hope so ;-)
EmiL - CSGO and more he has 7k now but still not enough
...and the next day it was 9.3k subs. It looks like the UA-cam "suggestion" algorithms have noticed the outpouring of likes, comments, and new subs and are referring more new viewers here. Personally, I think the presentation style and pacing are perfect.
I love alligators. Sleeper sharks and alligators. That's normal, right?
Dunno. I'd see a doctor for that ;)
Don't forget alligators
It’s normal to love animals, so I think so.
Yeah
Facts in Motion I don't think it's curable. Also, I don't want it cured. ;)
Your animation style feels kinda too close to kurzkesagt, but I do like the content and the visuals. Subbed
Wait what? I legit thought this was kerzkesagt ._.
Kurzkesagt does not own the paper layer over format
> kurzkesagt
> kerzkesagt
> Kurzkesagt
It's *Kurzgesagt*, people. *Kurzgesagt*. As in kurz=short and the past tense of sagen='to say', gesagt.
German connection.
Loved that Jurassic park reference you had going on.
Wunderschöne Animation!
Beautiful animation!
I can't believe this channel isn't famous
I first heard about this in a programme narrated by David Attenborough, about a project to increase the numbers of Galapagos giant tortoises.
He said that the importance of the temperature had only just become known, and the researchers were worried that they might have inadvertently produced same-sex hatchlings. but luckily the various incubators they used had enough temperature variation to ensure mixed-sex baby tortoises.
I couldn't remember which way round it was, or what the cutoff temperature was, so I'm very glad for this video for that alone.
Amazing! May I ask which software is used to make this animation?
Illustrator + after effects
Thank you! Your team have awesome designers :D
this is amazing! keep it up! ^_^
thanks - I will!
keep up the good work sir I always watch your videos
much appreciated
Your vids are petty good it reminds me of lemmino
Man these videos are awesome
Awwwww croc moms are so caring. That’s a heartwarming fact
It has been said that this way of sex-determination is what led to the demise of the non-avian dinosaurs.
The Gallus ;:-:;
Any sources? Because dinosaurs did inhabit cold and even polar environments. If the notion's implying what I think it is, it already makes no sense.
TyrannosaurusLives he means the ratio of males to females, not the variables that have to be met to be male or female.
Finn Clark
Oh. Still, sources would be lovely.
TyrannosaurusLives never mind he is saying what you are thinking, he is making no sense so yh, sources please lol
TyrannosaurusLives I made that comment randomly. But still, should I even edit that comment? Also, wouldn't polar dinosaurs choose between spring or summer to hatch their eggs? Plus, there wasn't any polar ice caps at the time, sea levels are very high and dinosaurs could just simply migrate to other areas if need be.
Crocodilians are one of the most successful species on the planet, having survived virtually unchanged since the time of the dinosaurs, that's a time span of 225 million years at maximum
Heck, there were even crocodilians BEFORE the dinosaurs, though not the ones we're familiar with today, still, that just goes to show, the Crocodilian family have been around for a LONG time, their species has not only seen the rise and fall of Empires and Civilisations,but the rise and fall of whole groups of animals and species
THAT'S what I call a survivalist
Commander Critic
That's nothing compared to jellyfish, which has existed for about 555 million years.
That's before the cambrian explosion and trilobites. Having seen entire animal phylums rise and fall is what i definitively call a survivalist.
I LOVE THIS CHANNEL.
This looks like Kurzgesagt's original animation style, which I absolutely love. Their style is evolving, which is good but this style brings a sense of nostalgia.
I love the animations
A purple ad came on and I decided to watch. Completely forgot that this was the video I was actually trying to watch
love the videos!
Great channel
You said Crocs and Gators, but the search bar said Gators and Crocs, anyone else notice?
Yes, that really annoyed me.
That moment you realize you spent the entire vid readin comments ;-;
Good job, Unknown Darkness.
Crocodilian moms are such good moms. Crocodile babies must be cute because they receive so much parental care.
They are
Very interesting thanks for that
not only is this an amazing video.... but is it just me or are mother crocodiles adorable? like, they are so loving to their brood from what i can understand from this video
Good video, keep it up
thanks!
U deserve more subs
This chanell is super awesome and I love it already. I only have one complain. Please get this annoying and distracting music away!!
i just learned something new, i would have never guessed a species sex could be determined by something like temperature, atleast not an animal as massive as a croc, thats something i would have expected more from an insect species.
(Edit: subbed)
Baby croc-a-gators and their calls are so cute! 😆
I didnt know that the mother croc would assist babies stuck in there eggs. Thats so sweet!
When I watched this you had exactly 60,000 subscribers.
crocs are ancient, theyve seen hotter and cooler global temps.. im sure they have some kind of adjustment mechanism
There's been something viral last year or so.
When it gets too cold, a certain species of crocs stick their snout out of the water, so they can breathe. Their metabolism slows down so much in the process, that they don't care about being frozen in place until it gets warmer again.
this guy should have almost 1M subs
remember kids always make sure your croc eggs are at the right temperature or else it will hatch into a 20 foot tall unholy chicken kraken hybrid
1:46 heh movie refrences
from jurassic park
It's nice to learn about reptiles that take care of its offsprings.
I understand the mechanism behind this.
If it’s too hot or too cold times are bad.
So a female is likely to give you at least some grand babies but not very many.
If times are good then you want males to fertilize as many females as possible and give you loads of grand babies.
This happens in leopard geckos too! We’re fairly certain that our gecko is what’s called a ‘hot female’, which happens when the critical temperature is hot enough to produce a mixed clutch. Sometimes when this happens a female will develop certain intersex characteristics, like being bigger, having large labial bumps, and producing less eggs, all of characteristics my gecko has. In fact, we didn’t even figure out she was female until almost a year of having her, and it took some intense examination. But, since she’s a rescue, we can’t know for sure. I’m not sure if this happens In crocodilians, but I wouldn’t be surprised.
Also some sea turtles! Great video
This guy needs more subs....
Deserves
*Seeing an amazing video fills you with determination
+1 sub love your videos
Ohhhh, baby crocodiles are adorable
1:47 Is that a Jusrassic Park 1 reference? The robotic arm? The old guy with a beard?
That’s pretty cool
Crocs have survived for Billions of years, I don't think they're gonna go extinct any time soon
And remember, Alligators Can't Chew Gumballs...
I like your voice :D
I knew this before but I don't know how.
I love your accent.
One word “sophisticated” describes everything you publish. May we know your name?
I'm impressed by the female croc's mothering skills, considering their specie's reputation.
Birds such as penguins use ZW sex determination, not XY
The naming of the chromosomes is completely arbitrary. The point was "If they have this combination of two chromosomes, female; if it's this other combination, it's male."
4:11 - the sun rises in front of the mountains
Interestingly Turtles gender is also determined by temperature during the incubation period, with warmer temperatures resulting in Female turtles.
and tortoises. The only other egg-laying reptiles I know of are snakes, and I wouldn't be surprised if they do this, too.
This seems like something out of SCP.
How about the other members of the order Crocodilia such as the gharial ?
why is Allent Grant SO GOD DAMN TOUCHY WITH THE EGGS 1:50
Honestly I heard this in a show and couldn’t believe it. Like how. Also how do they know when to make their nest to prepare for the eggs? And also how do they know to layer the nest for different genders?
I guess it’s genetically ingrained in all species to create shelter though which is also amazing to me.
dang. life and science are amazing.
As far i know of all reptiles have TSD, some breeders try to determine what sex they hatch, how ever its very tricky and dangerous for the hatchlings becase it might get to cold or hot, and like in a nest the temprature is not 100% equal in the incubator
I already knew how crocodiles sex was determined. Thanks Wild Kratts 🙃
considering a male can fertilize a tons of females that probably not going to be a issue
Why do you think most species on the entire planet have a 50/50 split in the first place? If it's really that simple, don't you think most species would be majority female?
That's heat temperature
TSD also works in turtles
I hope crocodiles don’t go extinct :(
yeah would be a shame. They also fill an important role in the food chain. So it might have consequences for alot of other animals too.
Since these creatures had survived many events that caused extinction of other species in the past.
I doubt they'll be extinct anytime soon.
Crocodile is a great parent
We already locate and protect sea turtle nests to help their populations. We could do something similar with Crocodiles, by locating nests, and artificially creating the right temperatures for some nests to hatch as all male. We can't give up preserving ecosystems without a fight.
In some crocs both mom and dad protect the babys
what is this first music
Shoulda done this in Jurassic Park
Interesting
I thought this was about how crocodiles had a system to remain determined at sex. I was not dissapointed
Is how tall we are solely determined by our DNA though?
Can you do alligators vs crocodiles
Cool
0:38 I'm really sure penguins, or at least most birds are a bit different too in that matter...
There's male, female and also hermaphroditism. Sometimes crocodilians or any animal can be gyneandromorphic, which means having mixed genotype and phenotype features other than the typical binary sexes. Genes are not always involved in developing bodies. In some cases, hormones and the environment influence the develop of the sexes. Sexual development isn't exactly a dichotomous ideology we can simply pick and choose. It's perfectly natural for the sexes to go in between in many species, including us.
How come crocodiles take care of their offsprings until their big enough to survive, but other reptile just abandon their eggs
Considering the population growth is tied more heavily to the number of females than the number of males, this tendency for more females to be born during times of temperature fluctuation, seems more like a survival strategy. So long as enough males are present, the population could in fact explode in size (one male can fertilize many females per mating season). And the more females giving laying eggs increase the chances that the conditions are right for a male to be born. For the population to remain stable, or to even grow, there doesn't need to be a balanced ratio of male to female, only that enough males be present. In fact, since sex is determined by temperature, and not a sex gene, it is impossible for males of these species to go extinct, only suppressed.
Also tortoises
Hey, if its okay next time can you add English Subtitles instead of German :)
interesting