Scientists say they have pinpointed the moment when humanity almost went extinct

According to a new study, ancient humanity was nearly wiped out around 900,000 years ago, when the global population dwindled to about 1,280 reproducing individuals. Moreover, the population of early human ancestors remained this small for about 117,000 years.

The analysis, published Aug. 31 in the journal Science, is based on a new computer model developed by a team of scientists based in China, Italy and the United States.

The statistical method used genetic information from 3154 current human genomes.

According to the study, about 98.7% of human ancestors have been lost. Researchers say the population crash is linked to a gap in the fossil record that may have given rise to a new hominin species that was the common ancestor of modern humans, Homo sapiens and Neanderthals.

“The new discovery opens up a new field in human evolution because it raises many questions, such as where these individuals lived, how they overcame catastrophic climate changes, and whether natural selection accelerated the evolution of the human brain during the Garden.” said senior author Yi-Hsuan Pan, an evolutionary and functional genomicist at East China Normal University, in a statement.

The research team suggests that the population hiatus coincided with dramatic climate changes known as the Middle Pleistocene Transition. Glacial periods became longer and more intense, which led to a drop in temperature and very dry climatic conditions.

Moreover, scientists have suggested that fire control, as well as a changing climate that was more hospitable to human life, may have contributed to the rapid population growth around 813,000 years ago.

The earliest evidence of using fire to cook food dates back to 780,000 years ago in what is now Israel, the authors noted.

Although ancient DNA has revolutionized our understanding of past populations, the oldest DNA of the human species dates back to about 400,000 years ago.

The computer model uses the vast amount of information contained in modern human genomes about genetic variation over time to estimate the size of populations at specific points in the past. The team used genetic sequences from 10 African and 40 non-African populations.

“Provocative” research

Commenting on the analysis published in the same journal, Nick Ashton, curator of Paleolithic collections at the British Museum, and Chris Stringer, research leader in human evolution at London's Natural History Museum, described the study as “provocative”.

Two researchers who were not involved in the study said it “brought the vulnerability of early human populations into focus”.

However, Ashton and Stringer said the fossil record, although sparse, showed that early human species lived in Africa and beyond from about 813,000 to 930,000 years ago – a period of proposed population collapse, the era fossils have found in present-day China. , Kenya, Ethiopia, Italy, Spain and the United Kingdom.

“Whatever caused the proposed disruption may have been limited in its impact on human populations outside the Homo sapiens lineage, or its effects may have been short-lived,” the two researchers said in a commentary.

“The proposed bottle needs to be tested against human and archaeological evidence,” they added.