New Research Suggests There Were Only 1,300 Humans Alive Nearly 930,000 Years Ago And They Almost Went Extinct
by Trisha Leigh
As if we needed proof that humans as we know them barely know how to survive, nevermind exist successfully, this new study claims just over 1200 of them making it is the reason we’re all here today.
The researchers say that a “severe bottleneck” around 930,000 years ago had the population of our human ancestors down to just about 1280 individuals capable of producing offspring.
They blame this bottleneck on glaciation events and claim they have a new method of accurately determining demographic inferences, called the fast infinitesimal time coalescent process.
The method revealed a 117,000-year bottleneck that wiped out 98.7 percent of the population and nearly eliminated Pleistocene ancestors altogether.
Which means every human alive today can trace their ancestry back to just 1280 individuals.
Senior author Giorgia Manzi explains in more detail:
“The gap in the African and Eurasian fossil records can be explained by this bottleneck in the Early Stone Age as chronologically. It coincides with this proposed time period of significant loss of fossil evidence.”
That said, plenty of others – like paleolithic archaeologist Nicholas Ashton, remain unconvinced.
“The hypothesis of a global crash does not fit in with the archaeological and human fossil evidence. Questions remain as to what triggered the bottleneck, and what, after 120,000 years, led to expansion.”
The study authors have many ideas as to what led to the bottleneck, but not any explanations for what caused the population to increase drastically later on.
They do think that the population squeeze likely helped differentiate between Neanderthals, Denisovans, and modern humans.
“The novel finding opens a new field in human evolution because it evokes many questions, such as the places were these individuals lived, how they overcame the catastrophic climate changes, and whether natural selection during the bottleneck has accelerated the evolution of human brain.”
The new study relies on a new computational model that looks at 3,154 moder-day human genomic sequences and extrapolates genetic mutations. From there, it walks backward through time to come to their conclusions.
People like Stephan Schiffels, the group leader for population genetics at the Max Planck Institute for Evolutionary Anthropology, are “extremely skeptical” of its accuracy.
Janet Kelso, a computational biologist at the Max Planck Institute, also doubts that this bottleneck could be as widespread as the authors believe, suggesting it might be more prevalent in present-day African populations only.
“The conclusions are intriguing but should probably be taken with some caution and explored further.”
Basically, though it’s interesting to think about, it doesn’t seem like most in the field are taking these results seriously.
At least, not without more studies to back it up.