Living Fossil: African coelacanth is not 65 mn years-old as evolution is evident in its genes

Back in 1938, the first living coelacanth was caught off the coast of South Africa, roughly 65 million years after it was believed to have been become extinct. Needless to say, the discovery caused quite a stir. While the fish went on to earn the moniker ’living fossil’ because of its anatomy that resembled fossilised records, researchers from the University of Toronto have now said that the genome of the ancient coelacanth tells a whole different story. According to a statement by the University of Toronto, the African coelacanth Latimeria chalumnae, gained 62 new genes through encounters with other species ten million years ago. As per study authors, the sequences suggest that the new genes arose from transposons, also known as ;selfish genes’ which are parasitic DNA elements whose sole purpose is to make more copies of themselves. The research highlights the dramatic effect the travelling trasposon DNA can have on creation of genes and also gives a glimpse into some of the forces that shaped the genome of the ancient creature. [caption id=“attachment_9296491” align=“alignnone” width=“1280”] The primitive-looking coelacanth has long been regarded as a ’living fossil,’ with extant specimens looking very similar to fossils dating back to the Cretaceous period. Image: Epic Wildife/Youtube[/caption] Senior study author Tim Hughes stated that their findings provide a striking example of transposons contributing to the host genome, adding that while they do not know what the 62 genes are doing, but many of them encode DNA-binding proteins and probably have a role in gene regulation. Lead study author Isaac Yellan stated that it was surprising to see coelacanths pop out among vertebrates since they have an undeserved reputation of being a living fossil. “The coelacanth may have evolved a bit more slowly, but it is certainly not a fossil,” Yellan added. Study authors have deduced that the transposons came into various lineages at different times by being carried between species through what’s known as horizontal gene transfer. The study’s findings were published in the journal Molecular Biology and Evolution.