Seals and sea lions are fast swimming ocean predators that use their flippers to literally fly through the water. But not all seals are the same: some swim with their front flippers while others propel themselves with their back feet.

Seals and sea lions are fast swimming ocean predators that use their flippers to literally fly through the water. But not all seals are the same: some swim with their front flippers while others propel themselves with their back feet.

In Australia, we have fur seals and sea lions that have wing-like front flippers specialised for swimming, while in the Northern Hemisphere, grey and harbor seals have stubby, clawed paws and swim with their feet. But the reasons why these two different ways of swimming evolved has perplexed biologists for generations. Is one style better than the other?

But now a Monash University-led interdisciplinary study published in Current Biology has used cutting-edge computer simulations alongside footage of live seals to finally answer this evolutionary mystery.

«The difference in swimming style between forelimb and hindlimb propelled seals is so great that these groups were originally thought to have evolved from separate land-dwelling ancestors,» said lead study author Dr David Hocking from the Monash University School of Biological Sciences, «but the genetics clearly shows that all living seals come from the same group of animals.»

The question is, how could such different swimming styles evolve within the one animal group?

Story Source:
Materials provided by Monash University. Note: Content may be edited for style and length.