Human Digits Came From Fish, Study Says

[mrmoshe]

Human digits came from fish, study says

Prehistoric 'finger' fins found in an Australian fish species led to the development of digits in humans, new research suggests.

Zerina Johanson, palaeontologist at London's Natural History Museum, said the small fin bones of Neoceratodus - also known as the Australian or Queensland lungfish - are much the same as fingers and toes in modern back-boned land animals.

"Where our fingers came from has been one of the biggest mysteries surrounding the move of our evolutionary ancestors from sea to land," Dr Johanson said.

The study, which also involved lungfish expert Jean Joss from Australia's Macquarie University, supports the findings of similar research into the evolution of fish fins into the limbs of tetrapods, or four-legged animals.

"How we got from a fish fin to a tetrapod hand, it seemed like a very substantial change," Dr Johanson told AAP.

"Now, with our research and the research of others, that gap is becoming narrower and narrower.

"There is not really that much of a difference between a fin and a limb anymore."

The development of fingers and toes in the embryos of land animals is closely linked to a particular gene, which acts in a distinctive pattern.

The study found an almost identical pattern in the fins of the Australian lungfish, suggesting digits are the equivalent of fin bones.

"We have a case of fish fingers in the Queensland lungfish," Dr Johanson said.

The Queensland lungfish is known as a living fossil because it has survived since first appearing on the fossil record more than 100 million years ago.

It is part of the lobe-fin group, which are the closest living relatives of land animals.

Australian lungfish occur naturally in just a few coastal river systems in south-east Queensland.

Earlier this month, Queensland Premier Anna Bligh announced a $35 million Freshwater Species Conservation Centre would be built near Gympie, aimed at ensuring the survival of the lungfish, Mary River cod and Mary River turtle.