To our knowledge, no species has ever manipulated its environment as successfully as Homo Sapiens. We have spread across the globe and, for almost our entire history, we have relentlessly turned the natural environment to our advantage.
However, this is not to say that this was always the case. There may be eight billion of us today, covering the planet with our society and our industry, but the path that got us here was far from straightforward.
In fact, but for an extraordinarily lucky moment in our evolutionary history, we wouldn’t be here at all.
The Dangers of a Bottleneck
Nor should we really be surprised by this. The success of any given species is tightly interwoven with its surroundings, and how well they can be exploited. Change the surroundings, and you change the game, losing some species in the process.
In fact, there used to be multiple human species, co-existing peacefully (well, sort of) alongside each other. The failure of all but one of those species should be a warning about how precarious our own hold on existence is.
And we were right up against it, almost a million years ago. We are in the Lower Paleolithic, the millions of years that made up the first and longest period of the Stone Age. Man was learning to control fire, and stone tools were appearing for the first time.
Researchers in China, studying the variations in the human genome, have found evidence that at this time, about 930,000 years ago, something catastrophic happened to humans. The population began to plunge, until we had almost all died out.
By the time it stabilized there were only 1,280 breeding adults remaining, a desperately low number for a population. As a reference, there are twice as many black rhinos in Africa today, and they are considered critically endangered.
And this wasn’t for some brief moment, either. The evidence suggests that this period of desperate survival, where we were almost lost as a species, went on for over 100,000 years.
There are some very interesting theories which come out of these findings, particularly given the timing of this evolutionary bottleneck. The humans at the time predate the evolutionary division that split homo sapiens from Neanderthals, and it is possible, according to the data, that this is the event that caused the split.
Did this drastic reduction lead the survivors down two separate evolutionary paths? Well, we might be perhaps getting a little ahead of ourselves here. For a start, there are a couple of problems with the research itself.
This assessment is based solely on genetic analysis, and there is no corroborating evidence to tell us that we once witnessed an enormous catastrophe, or even what that might be. All we have is a suddenly impoverished gene pool, suggesting that a lot was lost.
But, if it is true, then at some point almost a million years ago we were nearly all killed. The fact that we took 100,000 years to recover should show how delicate life can be.
Top Image: The most dangerous moment in human evolution: we were almost wiped out. Source: Graxaim / Adobe Stock.
By Joseph Green
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