There is no one set way in which seals swim through the water. For instance, in Australia, fur seals and sea lions utilise their wing-like front flippers for swimming whereas in the Northern Hemisphere, grey and harbour seals swim using their stubby clawed paws.
Scientists have been confused for some time over why these seals swim in different ways.
Utilising computer simulations alongside footage of live seals, Dr Ben Burville and scientists and engineers from Monash University uncovered the answer to this mystery. Whilst evidence in swimming style suggested the seals evolved from different ancestors, genetics proved that this was not the case; therefore something else would appear to answer the question.
After using fluid dynamics simulations to analyse how Antarctic seals swam, the scientists discovered wing-like flippers could evolve in seals which already swim with their back feet and therefore provided evidence for the evolution of forelimb swimming in both fur seals and sea lions.
As Dr Shibo Wang, Monash University engineer, explains, “our analysis showed that some Antarctic seals, like leopard seals, actually have very streamlined, wing-like forelimbs, despite being from the ‘foot-propelled’ seal family.” The team have supplementary footage of this from leopard seals at Taronga zoo.
This recent study has been published in Current Biology and will hopefully improve the future of marine science as Dr Hocking, lead study author from Monash University School of Biological Sciences, explains, the study “may help us improve the design of human-built machines like underwater drones and submersibles, increasing their speed, manoeuvrability or energy efficiency.”
