Imagine for some time in history, human ancestors came very close to being wiped out, with the global population shaved down to just 1,300 individuals. Imagine it. A team led by Yi-Hsuan Pan and Haipeng Li of the Chinese Academy of Sciences was finally able to push the frontiers of the genetic past even further to this very dramatic population crash, untying it to 900,000 years ago.
It is unimaginable that researchers were interested in genes that could be so easily altered to the effect that their computations would have been real and/or accurate. Comparing genomes from 3,154 humans across population groups, scientists figured out the human population was reduced to an unprecedented 99% at that time. But more important is that this small population remained the same even past the 100, 000 years.
But what could be the reason for this? Therefore, some naturally occurring catastrophies like extreme drought, sudden drops in water temperature etc., had been suggested by researchers as a potential drive which could be held in charge for this decline measurement. Leaving some questions adjar and initiating several arguments among a lot on scientists at once.
For example, Kelso said this collapse as a population examined over time had appeared more apparent only in African populations. “Though intriguing, should probably be taken with some caution and explored further,” she noted.
Among other experts who reacted to the report was Nick Ashton, who works at the British Museum, who said the study was “provocative,” one that had made a good point that early human populations were vulnerable; meanwhile, others such as Chris Stringer, located at London’s Natural History Museum, said the fact still stands that in passing, the fossil record witnessed human species in and out of Africa during that time.
Can you imagine the kind of life that would have been led by our ancestors at this time of the bottleneck? The serious challenges were harsh climates characterized by extreme cooling, generally occasioning food shortage. However, this is believed by researchers to have called for never-before-seen unity and adaptability on the part of our ancestors. “We believe that our ancestors must have been well-united to fight against the harsh environment,” noted Pan and Li.
This use of fire, circa 780,000 years ago, combined with more favorable climatic shifts, may have been enough to cause a rapid population increase later. Indeed, the ability to cook food would have provided such a survival edge that human ancestors finally were able to thrive again.
Now, you may be wondering why we don’t have more genetic diversity, considering our spread across the globe. That bottleneck and others like it shaped the course of our genetic heritage. With every migration, when a small group of humans adventurous enough to leave Africa did so, it turned out to be a “founder effect” that saw new populations diverging genetically from their ancestors. That is why African populations are treated with far greater genetic diversity than those in the Americas.
While the Toba supervolcano theory once suggested an argument for a bottleneck some 70,000 years ago, newer evidence probably rules out this eruption since the same bottleneck theory argues humans did not experience it in either India or East Africa. This then opens things up for other events, such as large-scale diseases or even just patterns of migration, to have been the case with this genetic bottleneck.
Whatever be the reason, the fact indeed is that our ancestors emerged safe from all the dangers. Their resilience has indelibly marked our genes. How much the Homo sapiens, Neanderthals, and Denisovans have been influenced by the evolution emerged. The more we hang on and know about the past, the more obvious it becomes that they were periods of time which played some role in laying the pathway of Man.
The next time one is in awe of feats, one has to throw one’s mind back judiciously by 900,000 years to the forefathers of today. Their threatened survival by adversities was the base for the rich and varied world in which we finally live today. This not only enriches our curiosity about our journey of evolution but also enhances appreciation for resiliency unmistakably defining our species.
