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Trumansfangs
Missouri Fan
Town & Country
Member since Sep 2018
2917 posts

Why crocodiles have changed so little since the age of the dinosaurs

Sciencedaily

Image: https://www.sciencedaily.com/images/2021/01/210107083751_1_540x360.jpg


Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago. There are also very few species alive today -- just 25. Other animals such as lizards and birds have achieved a diversity of many thousands of species in the same amount of time or less.

Prehistory also saw types of crocodile we don't see today, including giants as big as dinosaurs, plant-eaters, fast runners and serpentine forms that lived in the sea.

In the new research, published today in the journal Nature Communications Biology, the scientists explain how crocodiles follow a pattern of evolution known as 'punctuated equilibrium'.

The rate of their evolution is generally slow, but occasionally they evolve more quickly because the environment has changed. In particular, this new research suggests that their evolution speeds up when the climate is warmer, and that their body size increases.

Lead author Dr Max Stockdale from the University of Bristol's School of Geographical Sciences, said: "Our analysis used a machine learning algorithm to estimate rates of evolution. Evolutionary rate is the amount of change that has taken place over a given amount of time, which we can work out by comparing measurements from fossils and taking into account how old they are.

"For our study we measured body size, which is important because it interacts with how fast animals grow, how much food they need, how big their populations are and how likely they are to become extinct."

The findings show that the limited diversity of crocodiles and their apparent lack of evolution is a result of a slow evolutionary rate. It seems the crocodiles arrived at a body plan that was very efficient and versatile enough that they didn't need to change it in order to survive.






GurleyGirl
Georgia Fan
Georgia
Member since Nov 2015
11836 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
Well duh.
Their environment has not changed sufficiently for mutations to be a factor in their survival. If we ever have another Ice Age that covers most of the planet, then crocs can likely kiss it goodbye.


Arksulli
Arkansas Fan
Fayetteville
Member since Aug 2014
20586 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
quote:

Their environment has not changed sufficiently for mutations to be a factor in their survival. If we ever have another Ice Age that covers most of the planet, then crocs can likely kiss it goodbye.


Or not. They've survived multiple Ice Ages. We know, from recent research and footage, that American Alligators can survive having their pond frozen over just fine thank you. They have survived climate changes from the time of the Dinosaurs till now just fine. It is them and sharks and the sharks might be sucking hind tit in this one.

The biggest threats crocodiles have faced is... well... us. We are smart enough and wide spread enough to actually cause their numbers to decline to the level only an extinction event causes. Though, it should be noted, we are, evidently, an extinction level event as a species.

What we do know is that while we can push crocodilian species to the breaking point if we let up for a short period of time they bounce right back. Alligators were greatly endangered once upon a time not that long ago. Now they freely roam the golf courses of the South.

We can, it is certain, if we work at it, take the Crocodiles with us if we die as a species. It is far more likely they outlive us and finally shuffle off this mortal coil when the Earth can no longer support large multi-cell creatures.


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Kentucker
Kentucky Fan
Cincinnati, KY
Member since Apr 2013
16404 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
Crocs are not very diverse but there are some species that are down to a single type. Aardvarks, aye-ayes, and humans are among the species with no close living relatives.


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21
tokenBoiler
Purdue Fan
Lafayette, Indiana
Member since Aug 2012
3158 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
'Cause who the hell is going to make them?


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20
Hardy_Har
Mississippi St. Fan
MS
Member since Nov 2012
16210 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
Their women are content..


SoFla Tideroller
US Marine Corps Fan
South Florida
Member since Apr 2010
20012 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
So, with Al Gore telling us that my pickup truck is causing our atmosphere to heat up, we should be seeing 75' crocs here shortly, right?


Miznoz
Missouri Fan
St. Louis
Member since Dec 2018
681 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
quote:

So, with Al Gore telling us that my pickup truck is causing our atmosphere to heat up, we should be seeing 75' crocs here shortly, right?


Why do people misunderstand things on purpose and then say they sound stupid?


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16
kywildcatfanone
Kentucky Fan
Wildcat Country!
Member since Oct 2012
78144 posts

re: Why crocodiles have changed so little since the age of the dinosaurs


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11
LewDawg
Georgia Fan
Richmond Hill, GA
Member since May 2009
70356 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
Gee, I don't know, Cyril. Maybe deep down I'm afraid of any apex predator that lived through the K-T extinction. Physically unchanged for a hundred million years, because it's the perfect killing machine. A half ton of cold-blooded fury, the bite force of 20,000 Newtons, and stomach acid so strong it can dissolve bones and hoofs.


olddawg26
Georgia Fan
Member since Jan 2013
21792 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
They haven’t changed because they’re so ornery.

And they’re so ornery cause they got all those teeth and no toothbrush


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100
arcalades
LSU Fan
USA
Member since Feb 2014
15701 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
satanic nonsense


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coachcrisp
Alabama Fan
pensacola, fl
Member since Jun 2012
21757 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
quote:

It seems the crocodiles arrived at a body plan that was very efficient and versatile enough that they didn't need to change it in order to survive.

So what's been said in all those words is:
Why change? Up til now, everything's been pretty much ok


Arksulli
Arkansas Fan
Fayetteville
Member since Aug 2014
20586 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
quote:

Why change? Up til now, everything's been pretty much ok


The thing is... they have changed. In a lot of small ways.

There were crocs, not that long ago, that would have made you poop yourself if you saw them. We are talking 40+ foot long monsters that could swallow you in a single gulp.

The basic body type though, that works. So, you have big crocs when there is a lot of big prey, and small crocs where there is a lot of small prey.

The thing is... with crocs, you have the dreaded medium size crocs/alligators that are just fine eating smaller prey but will happily kill and eat your ass.

I will post something on this later but they are like crabs... and most "crabs" aren't actually crabs. They are perfectly adapted to their environment. With even a little breathing room they thrive.


Miznoz
Missouri Fan
St. Louis
Member since Dec 2018
681 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
paraphrased Fun fact crab anatomy has evolved independently 6-7? times. There's a joking law of evolution that everything will eventually evolve into a crab.


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awestruck
Auburn Fan
Member since Jan 2015
7679 posts

re: Why crocodiles have changed so little since the age of the dinosaurs
quote:



The thing is... they have changed. In a lot of small ways.
However they've always remained strict carnivore's ... which kicks specialty diet's like paleo, keto, and vegan in the teeth.


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