Nature & Environment
Is the coelacanth really a 'living fossil' ?
By T.K. Randall
February 12, 2021 · 6 comments
Coelacanths have been around for a long, long time. Image Credit: Citron / CC-BY-SA-3.0
New evidence has cast doubt on the idea that the coelacanth hasn't changed at all in millions of years.
Large, elusive and found deep in the oceans where they had until relatively recently remained hidden away from human civilization, the coelacanth was first discovered in 1938 at a time when fossil evidence seemed to suggest that it had been extinct for 66 million years.
Its remarkable similarity to fossil specimens from that era led scientists to declare it a 'living fossil' - a moniker given to creatures that have remained practically unchanged since prehistoric times.
Now however, a new study published in Molecular Biology and Evolution
has called into doubt the whole idea of the 'living fossil' by revealing that, contrary to popular belief, at least one species of coelacanth has acquired dozens of genes over the last few million years.
The suggestion that the coelacanth is unchanged from its prehistoric forebears, therefore, is incorrect.
"Previous research has found that while coelacanth genes have evolved slowly compared to other fish, reptiles, and mammals, its genome as a whole has not evolved abnormally slowly and is hardly inert," said study author Isaac Yellan.
"I think that as more and more genomes are being published, the 'living fossil' concept is becoming increasingly something of a misconception, and I think many scientists would probably hesitate to assign it to any species."
Source: IFL Science
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