From coelacanths to crinoids: these 9 ‘living fossils’ haven’t changed in millions of years

Wed, 26 Oct 2022 04:04:54 +1100

Andrew Pam <xanni [at] glasswings.com.au>

Andrew Pam
<https://theconversation.com/from-coelacanths-to-crinoids-these-9-living-fossils-havent-changed-in-millions-of-years-188886>

"We see evolution all around us, constantly, in every living thing. Yet in the
deep oceans we find a number of “living fossils” reminiscent of creatures from
prehistoric times.

In his 1859 book On the Origin of Species, esteemed naturalist Charles Darwin
coined the term “living fossil” to describe living organisms that appeared
unchanged from their extinct fossil relatives. The term has since been used to
describe long-enduring lineages, relict populations, groups with low diversity,
and groups with DNA that has hardly changed in millions of years.

The marine depths seem to be a good place for “living fossils”, with
cartilaginous fish such as sharks and rays generally being 2-4 times more
evolutionarily distinct than land animals. In other words, while every species
is unique, these species are particularly unlike their closest relatives.

Let’s take a look at some of these relics from the past."

Share and enjoy,
               *** Xanni ***
--
mailto:xanni@xanadu.net               Andrew Pam
http://xanadu.com.au/                 Chief Scientist, Xanadu
https://glasswings.com.au/            Partner, Glass Wings
https://sericyb.com.au/               Manager, Serious Cybernetics

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