‘Punctuated equilibrium’ reason behind crocodile’s evolution: Study : The Tribune India

‘Punctuated equilibrium’ reason behind crocodile’s evolution: Study

Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago

‘Punctuated equilibrium’ reason behind crocodile’s evolution: Study

Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago.



Bristol, January 11

New research by the University of Bristol explained how a ‘stop-start’ pattern of evolution, governed by environmental change, could explain why crocodiles have changed so little since the age of the dinosaurs.

Crocodiles today look very similar to ones from the Jurassic period some 200 million years ago. There are also very few species alive at present. 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 study, published 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,” he added.

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.

This versatility could be one explanation of why crocodiles survived the meteor impact at the end of the Cretaceous period, in which the dinosaurs perished. Crocodiles generally thrive better in warm conditions because they cannot control their body temperature and require warmth from the environment.

The climate during the age of dinosaurs was warmer than it is today, and that may explain why there were many more varieties of a crocodile than we see now. Being able to draw energy from the sun means they do not need to eat as much as a warm-blooded animal like a bird or a mammal.

Dr Stockdale added: “It is fascinating to see how intricate a relationship exists between the earth and the living things we share it with. The crocodiles landed upon a lifestyle that was versatile enough to adapt to the enormous environmental changes that have taken place since the dinosaurs were around.”

The next step for the team’s research is to find out why some types of prehistoric crocodile died out, while others didn’t. —ANI

Tribune Shorts


Top News

Delhi police special cell raids homes of journalists linked to NewsClick

Delhi Police seal office of news portal NewsClick, raid premises connected to its journalists

Some journalists, including Urmilesh and Abhishar Sharma, ar...

AAP govt raised loans worth Rs 47,107 crore in 18 months of its rule, 57 per cent of this used to repay interest on loans, Bhagwant Mann informs governor

57% of loans AAP govt raised used on repaying interest on earlier loans, Bhagwant Mann tells governor

This is the gist of the letter sent by CM to Banwarilal Puro...

India tells Canada to withdraw 41 diplomats by October 10: Report

Amid strained relations, India tells Canada to withdraw 41 diplomats by October 10

Canada has 62 diplomats in India and India had said that the...

Two earthquakes hit Nepal, tremors in Delhi-NCR

4 earthquakes shake Nepal in an hour; tremors in north India

Tremors also felt in other parts of north India, including C...


Cities

View All