Strange thing happened to our ancestors 900,000 years ago – genetic research reveals

According to a new genetic study, a strange thing happened to our ancestors about 900,000 years ago.

Suddenly, the ancestral population of mankind dropped to a very low number. Only 1,300 spawners remained. The researchers in the study say the population will remain low for the next 100,000 years or more.From the modern point of view, it seems that suddenly everyone disappears. Obviously, the human race is on the verge of extinction. How is this possible and how reliable is this study?

Variation in the living human genome was analyzed by researchers Yi-Hsuan Pan Haipeng Li and their colleagues, and the study was published in the journal Science.

The results of the study are certainly both intriguing and surprising, and some scientists have questioned the genetic analysis.

Demographic bottlenecks occur when an existing population is downsized. It could be due to natural disaster, war, pandemic or something like that. When one population leaves to find another, genetic diversity is suddenly lost.

There is prior evidence of population bottlenecks that occur as humans evolve and move from one part of the world to another, but such drastic reductions in size are unusual.

Populations that lived 1 million years ago are of particular interest because many of our closest relatives emerged at this time, one of which gave rise to our lineage.

As the journal Science explains, the scientists “developed a new statistical method in this new study. To reduce computational costs and reduce winding errors to date, their model uses only a subset of genes, such as those that are not affected by forces such as selection. Active filtering changes mutation rates – to estimate population sizes at different points in time.

Using this method, they synthesized when genetic changes appeared in the genomes that were detected. Prior sequencing of 3,154 individuals from 10 modern African populations. and 40 modern non-African populations. Population size and history influence the accumulation of these changes, and scientists can analyze them to determine how many people lived at different times. Looking at the timelines, Pan and Li noticed a very sharp decline – about 99% – in the reproductive population of our ancestors around 930,000 years ago.They report that the number of breeding pairs has dropped by at least 100,000 to 1,280. (The total population, including children and the elderly, would have been higher.) Low population numbers persisted until about 813,000 years ago, when numbers began to increase again, the report by researchers.

It’s not clear exactly what pushed our species to the brink of extinction, but Pan and Li suggest that prolonged ice ages, cooling sea surface temperatures or drought may play a role important.

According to Joshua Akey, an evolutionary geneticist at Princeton University who was not involved with the work, the new study “fills in a few more pieces of the human evolutionary history puzzle.” “There may be some fine-tuning of the exact time frame and severity,” Akey says, but “the evidence of a severe bottleneck seems pretty compelling.”

However, it is vital to keep in mind many scientists are skeptical, mainly due to the lack of evidence backing up these low numbers.

Janet Kelso, a computational biologist at the Max Planck Institute for Evolutionary Anthropology, points out that a strong genetic bottleneck signal can be found in present-day African populations but not outside populations. Kelso says  the results are  intriguing but “should probably be taken with some caution and explored further.”

The study was published in the journal Science

Written by Jan Bartek – AncientPages.com Staff Writer