Scientists: humanity almost went extinct 900,000 years ago, our species was saved by 1,280 people
Mankind miraculously survived the harsh conditions of ancient Earth that killed 98.7% of the population about 900,000 years ago. The terrible period in human history lasted about 117,000 years.
This is evidenced by a new study published in Science. Despite the tragedy of this event, scientists believe that it had an important evolutionary significance, causing a faster development of intelligence in ancient people.
The study was carried out by a team of scientists from the US, Italy and China who may have finally managed to find an explanation for the large gap in the fossil remains of Africa and Eurasia. Scientists estimate that there were only 1,280 people alive on the entire planet between 800,000 and 900,000 years ago, which subsequently saved the human race from total extinction.
Scientists used a new method called fast infinitesimal time coalescent process (FitCoal) to determine ancient demographics using modern human genome sequences from 3,154 people.
FitCoal helped scientists calculate what this long-standing loss of life and genetic diversity looked like using modern genome sequences from 10 African and 40 non-African populations.
"The gap in African and Eurasian fossils can be chronologically explained by this bottleneck in the Early Stone Age," said study co-author Giorgio Manzi, an anthropologist at Sapienza University.
Scientists suggest that it was due to extreme climatic changes. Specifically, there were changes in temperatures that led to droughts, which reduced food sources as animals such as mammoths, mastodons and giant sloths became extinct.
The study found that approximately 65.85% of modern genetic diversity may have been lost during this period, which only made it harder for this minimal number of individuals to survive, saving the entire species through successful reproduction.
This situation may also have favored speciation, where two or more species arise from a single lineage. During this speciation, two ancient chromosomes converged to form what is now chromosome 2 in modern humans.
This chromosome is the second largest chromosome in size, encompassing about 243 million DNA base pair building blocks.
"The discovery opens a new field in human evolution and raises many questions, such as where these people lived, how they overcame catastrophic climate change and whether natural selection during the bottleneck accelerated the evolution of the human brain," study co-author and evolutionary and functional genomics expert Yi-Hsuan Pan of East China Normal University said in a statement.
The scientists intend to continue searching for answers in future studie to know how such a small population survived the harsh climate conditions. It is quite possible that the rapid recovery of the population occurred about 813 thousand years ago when the climate became less severe and people learned to control fire.
Earlier OBOZREVATEL reported about a skull of a previously unknown species of human that was discovered in China.