Wednesday 10 February 2021

Coelacanth- not a living fossil.


Huge Fish, Once Believed Extinct, Isn’t the ‘Living Fossil’ Scientists Thought

An analysis of coelacanth DNA suggests its genome has experienced some significant changes in recent evolutionary history, potentially dispelling the popular image of these iconic fish as being “living fossils.”

The discovery of a live coelacanth (pronounced “see-lah-kanth”) off the coast of South Africa in 1938 was quite the shock, as these animals were believed to be extinct. The large fish were thereafter referred to as “living fossils” owing to their uncanny resemblance to near-identical species spotted in the fossil record.

New research published in Molecular Biology and Evolution presents evidence showing that at least one species of coelacanth, formally known as Latimeria chalumnae, is not the living fossil it’s presumed to be, having acquired dozens of new genes in the past 23 million years — a surprising finding, and a far cry from the idea that the species has barely changed since its ancestors emerged over 300 million years ago. What’s more, the finding is further evidence that the living fossil concept is outdated and somewhat of a misnomer.

“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 Yellan.

To which he added: “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.”


I have frequently written in this blog how any creature would have to have evolved to survive in modern times .The pollution alone would mean evolving to survive.Any so called dinosaur would have changed possibly in size and shape to compete for food and to breathe the air or live in the polluted rivers and seas.As predator/prey relationships change so the animals  have to evolve or die. The things prehistoric animals ate whether  flesh or plant no longer exist in many cases and would force a change.The question is would we still recognise them or would they have changed so much they may be something we think of as every day creatures such as the birds in our gardens?

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