An analysis by scientists at Sapienza University in Rome showed that the total population of our ancestors had declined to about 1,280 individuals, for a period of about 117,000 years. Researchers believe that this population decline was preceded by an extreme climatic event that brought the world close to annihilation of humanity, or human ancestors.
The period of this population decline coincides with a period of extreme frosts and prolonged droughts in Africa and Eurasia during the Quaternary period. At this time, our population began to decline drastically. However, even this small number of our ancestors managed to reproduce enough to avoid complete extinction.
In their research, the team has developed a new statistical method that allows them to estimate the time and size of ancient populations, while examining the shared genetics of modern humans with their ancestors.
The genetic data for the entire study came from 3154 people from 10 African populations and 40 European and Asian populations. The experts obtained this information from two scientific databases of human DNA.
The ancestor of the wise man
Scientists believe that an existential decline may have triggered the emergence of a new species, Homo heidelbergensis (Heidelberg man), which some say is a common ancestor of modern humans and our relatives Neanderthals and Denisovans. Modern Homo sapiens is thought to have appeared about 300,000 years ago.
“It’s lucky we didn’t go extinct. But we know from evolutionary biology that the emergence of a new species can occur in small, isolated populations,” Professor Giorgio Manzi, an anthropologist at Sapienza University in Rome and lead author of the research, told The Guardian.
This population decline coincides precisely with the gap scientists have so far in the available fossils found.
“We know that before about 900,000 to 600,000 years ago, the fossil record from Africa is very rare, even almost absent, whereas before and after that time we have more evidence,” Manzi noted.
“The same can be said for Eurasia: for example, in Europe we have a species known as Homo antecessor (human ancestor) about 800,000 years ago – and then nothing for about 200,000 years,” he added.
