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evidence that the living fossil concept is outdated and somewhat of a misnomer.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.”
Source:
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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