Strange Walking African Fish Reveals How Our Ancient Ancestors Evolved (VIDEO)
(Photo : A. Morin, E.M. Standen, T.Y. Du, H. Larsson)
Scientists are learning a bit more about how our ancestors evolved by examining a strange, walking fish. They're finding out what might have happened in the past when fish first attempted to walk out of water, eventually evolving into tetrapods, which include today's amphibians, reptiles, birds and mammals.
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The fish in questions is called Polypterus, which is an African fish that can breathe air, "walk" on land, and looks very similar to the ancient fish that eventually evolved into tetrapods. That's why scientists examined this species in order to learn a bit more about its unusual characteristics.
"Stressful environmental conditions can often reveal otherwise cryptic anatomical and behavioral variation, a form of developmental plasticity," said Emily Standen, the lead of the project, in a news release. "We wanted to use this mechanism to see what new anatomies and behaviors we could trigger in these fish and see if they match what we know of the fossil record."
Within a stressful environment, the fish showed significant anatomical and behavioral changes. For example, the terrestrialized fish walked more effectively by placing its fins closer to its body, lifting its head higher, and even kept its fins from slipping as much as fish that were raised in water. In addition, the fish' pectoral skeleton changed to become more elongate with stronger attachments across their chest as a possible attempt to increase support during walking.
"Because many of the anatomical changes mirror the fossil record, we can hypothesize that the behavioral changes we see also reflect what may have occurred when fossil fish first walked with their fins on land," said Hans Larsson, one of the researchers.
The findings reveal a bit more about the process of evolution and show how fish may have evolved in the past. In fact, this is the first example that demonstrates developmental plasticity that may have allowed for a large-scale evolutionary transition.
The findings are published in the journal Nature.
Want to learn more? Check out the video below, courtesy of YouTube.