Horizontal gene transfer: in large animals (Introduction)

by David Turell , Thursday, June 10, 2021, 18:26 (1262 days ago) @ David Turell

A new assertion:

https://www.quantamagazine.org/dna-jumps-between-animal-species-no-one-knows-how-often-...

"To survive in the frigid ocean waters around the Arctic and Antarctica, marine life evolved many defenses against the lethal cold. One common adaptation is the ability to make antifreezing proteins (AFPs) that prevent ice crystals from growing in blood, tissues and cells. It’s a solution that has evolved repeatedly and independently, not just in fish but in plants, fungi and bacteria.

"It isn’t surprising, then, that herrings and smelts, two groups of fish that commonly roam the northernmost reaches of the Atlantic and Pacific Oceans, both make AFPs. But it is very surprising, even weird, that both fish do so with the same AFP gene — particularly since their ancestors diverged more than 250 million years ago and the gene is absent from all the other fish species related to them.

"A March paper in Trends in Genetics holds the unorthodox explanation: The gene became part of the smelt genome through a direct horizontal transfer from a herring. It wasn’t through hybridization, because herring and smelt can’t crossbreed, as many failed attempts have shown. The herring gene made its way into the smelt genome outside the normal sexual channels.

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"Nor are the smelt unique. Recent studies of a range of animals — other fish, reptiles, birds and mammals — point to a similar conclusion: The lateral inheritance of DNA, once thought to be exclusive to microbes, occurs on branches throughout the tree of life.

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"...the smelt discovery and other recent examples all point to horizontal transfers playing an influential role in evolution."

Comment: The paper then covers many pages of research review om possible mechanism including parasite transfer. Nothing is conclusive but it certainly fits my notion of God dabbling.