New research by scientists University of Bristol The “stop-start” evolutionary pattern driven by environmental change explains why crocodiles have changed so little since the age of dinosaurs.
Crocodiles are very similar to what they are today Jurassic period about 200 million years ago. There are still very few species today – only 25. Other animals, such as lizards and birds, have acquired thousands of species at the same time or in less time.
History has seen species of crocodiles that we do not see today, including dinosaurs, herbivores, fast runners, and sea-serpentine forms.
In a new study published in the journal today Biology of Natural Communication, Scientists explain how crocodiles followed a model of evolution known as “dotted equilibrium.”
The rate of evolution is generally slow, but they sometimes grow faster as the environment changes. In particular, this new study shows that evolution accelerates and body size increases when the climate is hot.
Crocodiles have had many more forms in the past. Examples include fast runners, drill and burrowing forms, herbivores, and ocean-going species. Credit: University of Bristol
Leading author Dr. Bristol University School of Geographical Sciences. Max Stockdale said: “Our analysis used a machine learning algorithm to estimate the rate of evolution. The rate of evolution is the amount of change that takes place over a period of time, and we can do this by comparing measurements in fossils and considering how old they are.
“We measured body size for research because it’s important because how fast animals grow, how much food they need, how large their populations are, and how they interact with the likelihood of depletion.”
The findings show that the limited diversity of crocodiles and their lack of evolution are the result of slow evolution. The crocodiles saw that they had come up with a very efficient and versatile body plan that they did not need to change in order to survive.
This versatility may be an explanation for the fact that crocodiles eventually survived the effects of meteors Chalk the period when the dinosaurs became extinct. Crocodiles generally thrive in hot conditions because they cannot control body temperature and are required to want warmth from the environment.
The climate in the dinosaur era was warmer than it is today, which may explain why there are more species of crocodiles than we see today. Being able to draw energy from the sun means that they do not need to eat as much as a warm-blooded animal like a bird or a mammal.
Dr. Stockdale added: “It is very interesting to see how complex the connection is between the earth and the living things we share. Crocodiles have become so versatile that they can adapt to the enormous environmental changes that have taken place since the time of the dinosaurs. ”
The next step for the team to investigate is to find out why some prehistoric crocodile species died and some did not.
Reference: “Environment of Body Evolution in Archasaurs in the Crocodile Line” by Dr. Maximilian T. Stockdale and Professor Michael J. Benton, January 7, 2021, Biology of Natural Communication.