Genomic research reveals a startling decline in the numbers of human ancestors
The basic formulation of our new inference method is presented. The image depicts a cliff panel, showing a human ancestral population banding together to survive an unknown danger in the dark during a severe ancient bottleneck. Credit: Shanghai Institute of Nutrition and Health, CAS
The new genomic model suggests there was a major bottleneck in the human ancestor population between 800,000 and 900,000 years ago, which is consistent with the age of the last common ancestor of Denisovans, Neanderthals, and modern Homo sapiens. More archaeological evidence is needed for validation.
Between 800,000 and 900,000 years ago, there was a major collapse in the population of our human ancestors, according to a new study. In the paper, Wangji He and his colleagues present a convincing genomic model, suggesting that only 1,280 individuals existed during the transition from the Early Pleistocene to the Middle Pleistocene. This population bottleneck lasted for approximately 117,000 years.
At the beginning of the bottleneck, the number of ancestors saw a staggering 98.7% decline. This decline is linked to climate change characterized by extended glaciers, lower marine surface temperatures, and the potential for prolonged droughts across Africa and Eurasia.
Introducing the alliance model
He and his team pioneered the cohesion model, a tool designed to explore variation between genetic lineages and estimate past population sizes. They used this model to study the genetic sequences of 3,154 individuals from 10 African and 40 non-African groups. Their analysis showed a clear bottleneck across African populations. However, the bottleneck evidence was more precise in the 40 non-African populations. He and his team report that “the ancient bottleneck has been found directly in all 10 African populations, but only a weak signal of such a presence has been detected in all 40 non-African populations.”
Relationship to the last common ancestor
This proposed bottleneck is consistent with the time period in which many experts believe the last common ancestor of Denisovans, Neanderthals, and modern humans A wise man Live. However, from a related perspective, Nick Ashton and Chris Stringer argue that the bottleneck theory should be tested against concrete archaeological and paleontological human evidence.
“If, as seems likely, humans were widely dispersing within and beyond Africa in the period between about 800 and 900 thousand years before present… whatever cause of the inferred bottleneck was limited in its effects to non-broader regions.”The wise one Population ratios, or any effects were short-lived,” perspectiveH The authors add.
For more information about this research, see Detecting a near-extinction event for humanity.
References:
“Genomic inference of the severe human bottleneck during the early to middle Pleistocene transition” by Wangji Hu, Ziqian Hao, Pingyuan Du, Fabio Di Vincenzo, Giorgio Manzi, Jialong Cui, Yun-Xin Fu, Yi-Hsuan Pan and Haiping Li, 31 August 2023, Sciences.
doi: 10.1126/science.abq7487
“Did Our Ancestors Almost Die Out?” Genetic analyzes suggest ancient population collapse occurred 900,000 years ago” By Nick Ashton and Chris Stringer, August 31, 2023, Sciences.
doi: 10.1126/science.adj9484
