Polypterus, a fish out of water

Around 400 million years ago, fish left the water and started to evolve into land-loving creatures. But how did the transition happen?

Enter Polypterus. This African fish can breathe air, move across land, “and looks much like those ancient fishes that evolved into tetrapods.” With these traits in mind, Emily Standen and her team at McGill University embarked on a fascinating research project: Raising Polypterus in a damp terrestrial environment for almost a year, and then comparing it with Polypterus who were raised traditionally in water.

“We wanted to use this mechanism to see what new anatomies and behaviours we could trigger in these fish and see if they match what we know of the fossil record.”

Nature took a look at this fish out of water research in the 2014 video above, and revealed the not-so-surprising results—practice, practice, practice—and the surprising results—there were anatomical changes. Hans Larsson, Canada Research Chair in Macroevolution at McGill, explains:

“This is the first example we know of that demonstrates developmental plasticity may have facilitated a large-scale evolutionary transition, by first accessing new anatomies and behaviours that could later be genetically fixed by natural selection”.

File under biomechanics and evolution. Plus, watch more videos about walking fish on TKSST:
• The Mudskipper, an amazing amphibious fish
• The shark that walks: The bamboo shark or longtail carpet shark
• Fish that walk – Tasmania’s Spotted Handfish