Jerusalem Post covers research by Harvard University, University of Alberta, and North Carolina Museum of Natural History that reveals the long history of reptiles, who have reacted to past climate-change events more than 200 million years ago by evolving way quicker than usual when most species around them were going extinct:
Between the Middle Permian (265 million years ago) and Middle Triassic (230 million years ago) periods, two of the largest mass extinctions in history struck the Earth at the end of the Permian period.
The shifts studied in this particular paper, however, occurred far earlier, supposedly prior to the end of the Permian period. According to the study, the extreme increases in temperatures on the planet directly correlated with the rapid evolution of reptilian creatures of the time. This allowed them to survive the mass extinctions much more than the other animals, therefore allowing them to multiply rapidly after the fact.
“Some groups changed really fast and some less fast, but nearly all reptiles were evolving much faster than they ever had before,” said lead author postdoctoral fellow Tiago R Simões.
The researchers looked at over “1,000 fossil specimens from 125 species of reptiles, synapsids, and their closest relatives during approximately 140 million years before and after the Permian-Triassic extinction,” according to a Harvard University statement. They managed to find the earliest appearances of the different species and watch as they evolved during the subsequent fossils to track how fast they were changing.
Changes in size are the most noticeable change in these different species, and the causation can be easily traced. According to Simões, “small-bodied reptiles can better exchange heat with their surrounding environment,” while large-bodied reptiles could not do so just as well. Larger species such as crocodiles and dinosaurs, therefore, could not lose heat as well, forcing them to “quickly change their bodies in order to adapt to the new environmental conditions.”
Another change reptiles made due to the changes in temperatures was geographical; they would move to more temperate areas or the globe or submerge themselves in the marine world to cool themselves down.
Reptiles aren’t so lucky today, however. Recent studies have found that 21% of reptiles today are at risk of extinction, according to an April study published in Nature.
You can read more of the extinction vs. evolution study here, in Science Advances.