Human ancestors teetered on the edge of extinction thousands of years ago

A recent study, which encompassed genomic analyses of over 3,000 individuals, disclosed that the total population of human ancestors dwindled to a mere 1,280 individuals over a span of 117,000 years.

Scientists speculate that an extreme climatic event could have been the catalyst for this near-extinction of our human ancestors.

This decline seems to have coincided with significant shifts in the global climate, which transformed glaciations into lengthy periods, reduced sea surface temperatures, and possibly prolonged droughts across Africa and Eurasia. This timeframe also aligns with a conspicuous gap in the fossil record.

Italian anthropologist Professor Giorgio Manzi commented, "The numbers uncovered in our study mirror those observed in species currently facing extinction."

Nevertheless, Manzi and his colleagues posit that the existential pressures of this bottleneck may have spurred the emergence of a new species, Homo heidelbergensis, believed by some to be the common ancestor of modern humans, Neanderthals, and Denisovans.

"We are aware that approximately 900,000 years ago, the fossil record in Africa is nearly non-existent, despite having more fossil evidence before and after this period," noted Manzi. This phenomenon is also observed in Eurasia, where, for instance, Europe features a species known as Homo antecessor around 800,000 years ago, followed by a notable gap of around 200,000 years.

However, British Professor Chris Stringer raised an alternative perspective, highlighting the absence of convincing evidence for a global "gap" in the fossil record of early humans. Stringer suggested that it might have been a localized event, possibly linked to specific regions in Africa surrounded by desert.