About 1,280 breeding humans were alive in the world around 800,000 years ago

NEWS AND COMMENT: A new genetic analysis of more than 3000 living people has suggested that there was a bottleneck between 800,000-900,000 years ago on the planet and during this time our ancestors, the forebears of the human race today, almost became extinct with a mere 1280 breeding individuals. And this precarious situation, one of near extinction of our human ancestors, lasted for about 117,000 years.

Early human bottleneck. Only 1,280 breeding individuals in world 850,000 years ago.
Early human bottleneck. Only 1,280 breeding individuals in world 850,000 years ago. The image (marked up by me) is from Getty Images. Problem? Please comment and I’ll deal with it promptly – guaranteed.

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It makes one think. It makes one think of the possibility that humankind as we know it today might never have existed. The planet would have been an entirely different place. Sir David Attenborough once described humankind as a sort of disease spreading across the blue planet. Strong words. But from his perspective and in terms of wildlife conservation, preservation of nature and animal welfare in general, humans are a kind of disease. From their perspective we certainly are.

This is borne out in many ways such as the sixth mass extinction of wild species taking place currently with some shocking declines in population numbers, and global warming which itself is, according to reports, having a devastating effect on conservation. You don’t have to look very far on the Internet to find information about the sorry state of wildlife conservation on the planet because of increased human activity. It all comes back to increased human activity; primarily the destruction of wildlife habitat to make way for settlements, mining, you name it, nature has to be removed to make way for things that humans want to do including for example farming in the Amazon basin or on Borneo where millions of hectares of virgin forest has been burnt or hacked down. It is very depressing. I won’t go on.

This is about the near extinction of our ancestors and it appears that an extreme climate event caused this bottleneck as it is described. Incidentally, a bottleneck occurred with respect to the evolution of the cheetah many thousands of years ago which has resulted in today’s cheetah being inbred because there were so few cheetahs left on the planet that the foundation cats were so few resulting in inbreeding.

That is another story. Another aspect of this current story is that some scientists believe that a new species of early human emerged during this bottleneck, Homo heidelbergensis. They believe that it is a shared ancestor of modern humans and cousins to the Neanderthals and Denisovans.

Homo sapiens, our direct ancestors, emerged in Africa around 300,000 years ago, it is believed.

The lead author of the study, Professor Manzi, said that our ancestors were lucky to survive. The near extinction appears to align with changes in the global climate that turned glaciations into long-term events and a decrease in sea surface temperatures.

There was an extended period of drought in Africa and Eurasia which is believed may have combined to cause the bottleneck.

Fossil records are sparse during this period indicating the very low numbers of ancient humans at that time on the planet. Professor Manzi said that, “We know that between about 900,000 and 600,000 years ago, the fossil record in Africa is very scarce, if not absent, while both before and after we have a greater number of fossil evidence.”

He said that the same phenomenon concerns Eurasia. Not everybody agrees with him. Some believe that the bottleneck was a local phenomenon which meant that populations around Africa were affected rather than on other continents and areas.

His research is published in the science journal Science. His team analysed genomic sequences from 3,154 people alive today from 10 African and 14 non-African populations.

Comment: might be argued if one was entirely speaking on behalf of wildlife and the planet itself, that it was a great shame that our early ancestors did not become extinct. That humankind never existed. I suppose it is likely that some other humanoid species would have evolved. Perhaps they would have been worse than us. Perhaps they would have been better and more concerned with conservation rather than self-indulgent greed.

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