Homo erectus: Expert explains dating technique for Java fossils
Early human ancestors came close to eradication after a severe evolutionary bottleneck presented itself around 800,000 to 900,000 years ago
A new genetics analysis of more than 3,000 living people suggested that our ancestors’ total population sank to around 1,280 breeding individuals for about 117,000 years.
An extreme climate event may have resulted in the bottleneck which came close to wiping out our ancestral line, according to scientists.
Some scientists believe the existential event resulted in the emergence of a new human species, Homo heidelbergensis, which they believe is a shared ancestor of modern humans and our cousins, the Neanderthals and Denisovans.
Homo sapiens, meanwhile are thought to have emerged from Africa around 300,000 years ago.
READ MORE Ancient bone found in French cave could prove existence of unknown human species
“The numbers that emerge from our study correspond to those of species that are currently at risk of extinction,” said Professor Giorgio Manzi, an anthropologist at Sapienza University of Rome and a senior author of the research.
Prof Manzi is among those who believe that the extreme event may have produced the new human species.
He said: “It was lucky [that we survived], but … we know from evolutionary biology that the emergence of a new species can happen in small, isolated populations.”
The serious decline appears to align with big changes in the global climate that turned glaciations into long-term events, a decrease in sea surface temperatures.
An extended period of drought in Africa and Eurasia may have also combined to cause the bottleneck.
The team involved in the study also said the period coincides with a sparse period on the fossil record.
‘Strong’ face of ‘oldest known homo sapiens’ rebuilt by science[REPORT]
Neanderthal migration model hints at hidden archaeology sites in Iran[LATEST]
Caver recalls ‘speechless’ moment uncovering new species of human[INSIGHT]
We use your sign-up to provide content in ways you’ve consented to and to improve our understanding of you. This may include adverts from us and 3rd parties based on our understanding. You can unsubscribe at any time. More info
“We know that between about 900,000 and 600,000 years ago, the fossil record in Africa is very scarce, if not almost absent, while both before and after we have a greater number of fossil evidence,” Prof Manzi told The Guardian.
“The same can be said for Eurasia: for example, in Europe, we have a species known as Homo antecessor around 800,000 years ago and then nothing for about 200,000 years.”
Others are less sure that an event caused a global “blank” in the fossil record of early humans.
Some have suggested that whatever cause the bottleneck was entirely a local phenomenon, meaning that populations around Africa were affected rather than other Homo genus’ elsewhere.
Published in the science journal Science, the paper analysed genomic sequences from 3,154 people alive today, from 10 African and 40 non-African populations.
Looking at different versions of genes across a population, the scientists were able to estimate the date of when specific genes began to emerge.
The more time that has elapsed, the bigger the chance of different variants of a gene emerging.
From this, they looked at the frequency with which genes have emerged over time to gain insight into how ancestral populations grew and declined over time.
Source: Read Full Article