New research helps explain why an alligator’s appearance hasn’t changed over the past 200 million years.
In a latest study, scientists from the UK went to find out why “living fossils” or crocodiles have remained robust since the heyday of the dinosaurs. In the study, the researchers used “advanced evolutionary models” to show why some animals have remained the same since mass extinction between the Triassic and Jurassic periods.
Alligators from the dinosaur era still look like crocodiles today.
Sharing with The Conversation page, lead author Max Stockdale of the University of Bristol explained: “The parents of alligators have been around for a long time. Their fossils were found in rock from the early Jurassic period and date back to the time. About 200 million years ago Oddly enough, alligators from the dinosaur era still look amazingly like alligators today.
To study the evolution of the crocodile in more detail today, researchers put vast amounts of evolutionary data into a new mathematical model. They found that crocodiles, 25 of which are very similar species, evolved into a general form known as “interrupted equilibrium”.
Crocodile species start to develop quite a big body, sometimes it’s like a fan but also some species evolve faster.
But throughout its 200 million year history, crocodiles have evolved more slowly, so slowly that they still look exactly like crocodiles around 200 million years ago, and the evolutionary trajectory follows will certainly continue.
It’s a happy coincidence that slower evolving species know how to combine the best qualities, helping them to survive all growing conditions. Like ladybugs or cockroaches, alligators have qualities that are very similar to “polar creatures” – that is, they can survive extreme conditions, such as not needing to eat for long periods of time.
The discontinuous state of equilibrium is more common in organisms facing strong external pressure, especially after mass extinction, scientists say. Mass extinction also interrupted the advent of many new species.
Over its 200 million year history, crocodiles have evolved more slowly.
Basically, when the Earth is suddenly lifeless and when a new type of climate or environment emerges, mutants can now easily grasp this proper condition to grow and develop.
Crocodiles have passed through many Earth events to survive to this day. The same disrupted equilibrium model could be applied to other living fossils such as turtles, scientists say.
Understanding which animals live and appear unchanged over time, and which species have died, allows researchers to delve deeper into the evolutionary history of Earth.
