I’ve posted before on how long it might take to evolve and change the genetic structure of Homo sapiens. The answer so far seems to be ‘it depends on what the circumstances might be’. However, most people seem to vaguely agree that (a) species isolation and (b) climate change are the two most important factors.

All of which makes the case of Tibetan people fascinating. In yesterday’s Journal of Science, the Tibetan’s ability to thrive in high altitudes with low oxygen is the fastest genetic change ever observed in humans. It took just 2,750 years – which in geological time is about 1,000th of a blink.

Evolutionary biology researchers at the University of California-Berkeley said their study of the genomes of ethnic Tibetan and Han Chinese compared the genomes of 50 Tibetans and 40 Han Chinese. It purports to show that Tibetans rapidly developed a unique ability to survive in altitudes above 13,000 feet, where oxygen levels are about 40% lower than at sea level.

More than 30 genes with DNA mutations were found to be more prevalent in the Tibetans versus the Han Chinese, nearly half of which are related to how the body uses oxygen.

“For such a very strong change, a lot of people would have had to die simply due to the fact that they had the wrong version of a gene,” said Rasmus Nielsen, the integrative biology professor at Berkeley who was in charge of the research team.

The phrase that interests me here is ‘a lot of people would have had to die’. When (or if) global warming ever gets into its stride, a lot of people are going to die. Some of them immediately – from dehydration and starvation – but perhaps just as many from having the ‘wrong’ genetic code – ie, evolution will choose those gene combinations necessary to survive with higher temperatures and less water.

Britain is an island – as indeed Australia is an island continent. Assuming that international travel as we know it would break down following such a catastrophe, would the people in these two places evolve more quickly? Would they, perhaps, evolve in a different way and create a – perhaps two – different species? And with so many dead, might this mean Homo somethingelse could control his reproduction more successfully the next time around?