Only 1,280 Survived: Unveiling the Near-Extinction Event That Almost Erased Humanity 1 Million Years Ago

Nearly a million years ago, humanity faced a serious crisis. A recent study reveals that our ancestors may have been reduced to just about 1,280 individuals. This near-extinction event, called a “genetic bottleneck,” lasted for over 100,000 years but ultimately led to the diverse human population we see today.

The study, published in Science, highlights a critical moment in our history. By examining genetic data from 3,154 modern humans, researchers found evidence of a drastic population decline. Around 930,000 to 813,000 years ago, our numbers plummeted by 98.7%, leaving a tiny group of reproductive individuals.

This dramatic decline sheds light on why fossil records from that time are scarce, especially in Africa and Eurasia. It suggests early human populations were fragile, struggling to survive when faced with environmental challenges.

While the exact cause of this bottleneck is unclear, scientists suspect that severe climate changes played a significant role. As the Earth cooled during the middle Pleistocene, conditions like prolonged cold snaps and droughts likely led to food shortages. Humans may have been forced into smaller, isolated groups, competing for dwindling resources.

Fossil evidence from this era is hard to find, but genetic data helps trace the impact of these environmental shifts. As populations shrank, so did genetic diversity, leaving markers that connect climate changes with shifts in early human evolution.

One fascinating finding from the study is a major genetic change involving chromosome fusion. During this bottleneck, two chromosomes combined to form what we know as chromosome 2. This event, which set humans apart from other primates, likely occurred around the time of the population collapse.

Most great apes have 24 pairs of chromosomes, while humans have 23, thanks to this fusion. This genetic shift may have been crucial for the emergence of Homo sapiens and later divergence into Neanderthals and Denisovans. Such changes weren’t just genetic oddities; they laid the foundation for modern humanity.

As the climate improved around 813,000 years ago, humanity began to recover. With better conditions and the mastery of fire, early humans had a better chance of survival. Scientists are now investigating how these environmental changes and innovations sparked a surge in human population.

This study opens up new questions about natural selection during this time. Did the bottleneck speed up brain development? How did early humans adapt to the changing environment? Researchers are eager to explore these questions further.

Overall, this research offers vital insights into human evolution, particularly during the transition between early and middle Pleistocene. It helps explain how our ancestors overcame such a massive setback, shaping the path toward the modern human race we are today.

If you’re interested in more detailed findings, you can check the full study in Science here.

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