New research helps explain why the appearance of crocodiles hasn’t changed over the past 200 million years.
In the latest study, scientists from the UK investigated why “living fossils” or crocodiles have retained their rugged appearance since the heyday of the dinosaurs. In the study, the researchers used “advanced evolutionary modeling” to show why some animals have remained the same since the mass extinctions between the Triassic and Jurassic periods.
Speaking to The Conversation, lead author Max Stockdale of the University of Bristol explained: “The parents of the crocodile have been around for a very long time. Their fossils have been found in rocks since the early Jurassic and are around 200 million years old. Even stranger, these dinosaurs still look amazingly like today’s crocodiles. “
To further study the evolution of crocodilians today, the researchers fed a large amount 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 “broken balance.”
The first crocodiles had a fairly large body, sometimes it was like a fan, but there were also some species that evolved more quickly.
But over the course of 200 million years of history, crocodiles have evolved more slowly, so slowly that they still look exactly like crocodiles around 200 million years ago, and the evolutionary trajectory will certainly continue.
It’s a happy coincidence that slower evolving species know how to combine the best qualities, allowing them to survive in all growing conditions. Like ladybugs or cockroaches, crocodiles have qualities that are akin to “polar creatures,” meaning they can survive extreme conditions, such as not needing to eat for long periods of time.
Disruptive equilibrium is more likely to occur in organisms under strong external pressure, especially after mass extinctions, scientists say. Mass extinctions have also alternated with the birth of many new species.
Basically, when the Earth suddenly becomes deprived of life and when a new climate or environment emerges, mutants can easily grasp this suitable condition to grow and develop.
Crocodiles have gone through many earthly events to survive to this day. Scientists suggest that the same discontinuous equilibrium model could be applied to other living fossils such as turtles.
Understanding which animals are alive and whose appearance has not changed over time and which are dead helps researchers deepen the history of Earth’s evolution.
