London, UK: Analysis of genomic data from 3,154 modern humans indicates a dramatic population decline around 900,000 years ago, dropping from around 100,000 individuals to only 1,280 breeding individuals. This staggering 98.7 percent reduction persisted for 117,000 years and posed a severe threat to humanity’s survival.
The existence of our large and thriving population today serves as evidence that extinction did not occur. However, the findings, led by geneticists Mr. Haipeng Li from the Chinese Academy of Sciences and Ms. Yi-Hsuan Pan from East China Normal University in China, could provide an explanation for a puzzling gap in the human fossil record during the Pleistocene era.
“The gap in the African and Eurasian fossil records can be explained by this bottleneck in the Early Stone Age as chronologically. It coincides with this proposed time period of significant loss of fossil evidence,” said anthropologist Mr. Giorgio Manzi of Sapienza University of Rome in Italy.
When a species faces a devastating event like war, famine, or a climate crisis, reduced genetic diversity can be observed in the descendants of the survivors. This is how we’ve determined that there was also a more recent human population bottleneck in the Northern Hemisphere, occurring approximately 7,000 years ago.
“The novel finding opens a new field in human evolution because it evokes many questions, such as the places where these individuals lived, how they overcame the catastrophic climate changes, and whether natural selection during the bottleneck has accelerated the evolution of the human brain,” Ms. Pan stated.
Humans possess 23 pairs of chromosomes, whereas all other contemporary hominids, including the great apes, have 24. The development of chromosome 2 appears to have been a significant evolutionary event that set humans on a distinct evolutionary trajectory.