Crocodile evolution rebooted by Ice Age glaciations: Study

As per a study driven by McGill University, researchers have discovered impacts of Ice Age sea-level changes in the genomes of Caribbean and Pacific crocodiles in Panama. Crocodiles are resilient animals from a lineage that has survived for over 200 million years. Skilled swimmers, crocodiles can travel long distances and live in freshwater to marine environments. But they can't roam far overland. American crocodiles (Crocodylus acutus) are found in the Caribbean and Pacific coasts of the Neotropics but they arrived in the Pacific before Panama existed, according to new research.

Over 3 million years ago, the formation of the Isthmus of Panama altered global ocean circulation, connecting North and South America and establishing the Caribbean Sea. This resulted in widespread mixing of species on the continent and separation in the seas.

On land, mammals from North America such as mammoths, saber-toothed cats, horses, and camels invaded South America, and strange mammals like giant ground sloths, armadillos, and opossums from South America invaded North America.

The question a group of McGill and Panamanian researchers asked was: how distant are the Pacific and Caribbean populations from each other and do they match the geological record? Researchers have long suspected that American crocodiles living on the Pacific coast should have diverged genetically enough from Caribbean populations to become unique species. —ANI