Smithsonian Magazine
Originally Posted: April 16, 2015
Take a Deep Dive Into The Reasons Land Animals Moved to the Seas
Synthesizing decades of discoveries, scientists have revealed links between changing environments and animal movements
The movement of animals from the land into the sea has happened several times over the last 250 million years, and it has been documented in many different and singular ways. But now, for the first time, a team of researchers has created an overview that not only provides insight into evolution, but may also help more accurately assess humans’ impact on the planet.
Behind-the-Scenes With Curator Nick Pyenson: A New Fossil Whale
The oceans are teeming with tetrapods—“four-legged” birds, reptiles, mammals and amphibians—that have repeatedly transitioned from the land to the sea, adapting their legs into fins. The transitions have often been correlated with mass extinctions, but the true reasons are only partly known based on fossils and through study of Earth’s climate, for instance.
Those transitions are considered to be “canonical illustrations” of the evolutionary process and thus ideal for study; living marine tetrapods—such as whales, seals, otters and sea lions—also have a big ecological impact, according to Neil P. Kelley and Nicholas D. Pyenson, the two Smithsonian scientists who compiled the new look at these tetrapods, appearing this week in the journal Science. READ MORE