"Polar O'Bear"???

That's the headline of an article in the Daily Mail. It made me groan, even as I smiled.

A DNA study suggests that every polar bear alive today is descended from a single female brown bear living in Ireland during the last Ice Age, 10,000 to 110,000 years ago.

Although polar bears existed before that time, having evolved from a different group of brown bears in Siberia about 200,000 years ago, scientists say this Irish bear is their earliest known common ancestor.

The researchers studied samples of DNA taken from the bones and teeth of 242 brown bears and polar bears, including modern animals and fossilised bears that lived 120,000 years ago.

The analysis, published in the journal Current Biology, found that the mitochondrial DNA of living polar bears closely matches the genetic material taken from female brown bears living in Ireland 20,000 to 50,000 years ago.

. . .

Professor Mark Thomas, of University College London, who took part in the study, said: ‘Interbreeding between brown bears and polar bears is usually thought of as a dead end. But this shows it happened before and is part of the evolution of both species.’

He added: ‘The odd thing is that although polar bears and brown bears have been around for a long time, and are clearly different, these Irish brown bear genes have swept through polar bears so quickly.’

During the last Ice Age, polar bears roamed much further south than the Arctic.

At the time, Britain was connected to the rest of Europe by a land bridge, while ice sheets linked Britain with Ireland.

There's more at the link.

Clearly, ancient Guinness was rather more potent stuff than its modern equivalent . . . or was it the prehistoric poteen?





Peter