Ancestors of modern humans had sex with at least FIVE different archaic human species as they headed out of Africa
- Ancestors of modern humans interbred with five different archaic human groups
- Two of these groups are known, the Neanderthals and the Denisovans from Asia
- The others have been detected as DNA traces surviving in modern populations
- The researchers say that these archaic groups were widespread and genetically diverse, and survive in each of us today
Genetic analysis has revealed that the ancestors of modern humans interbred with at least five different archaic human groups as they left Africa and entered Eurasia.
DNA analysis reveals our ancestors moved east out of Africa and had several encounters with various different hominid species and mixed and mated with them.
Two of the archaic groups are currently known – the Neanderthals and their sister group the Denisovans from Asia.
But researchers, from the University of Adelaide’s Australian Centre for Ancient DNA, have detected traces of DNA from two mystery groups, which survives on only in modern populations – no physical remains have been found.
By mapping the location of past ‘mixing events’ they contrasted the levels of archaic ancestry in the genomes of present-day populations around the world.
Scroll down for video
Genetic analysis has revealed that the ancestors of modern humans interbred with at least five different archaic human groups as they moved across Eurasia. DNA analysis shows that as our ancient ancestors moved out of Africa they met and mixed with other groups
Dr Teixeira said that as these ancient people travelled further east away from the homeland of southern Africa they met and mixed with at least four other groups of archaic humans (pictured)
‘Each of us carry within ourselves the genetic traces of these past mixing events,’ said first author Dr João Teixeira, Australian Research Council Research Associate, ACAD, at the University of Adelaide.
‘These archaic groups were widespread and genetically diverse, and they survive in each of us. Their story is an integral part of how we came to be.
‘For example, all present-day populations show about two per cent of Neanderthal ancestry which means that Neanderthal mixing with the ancestors of modern humans occurred soon after they left Africa, probably around 50,000 to 55,000 years ago somewhere in the Middle East.’
They used information from reconstructed migration routes and fossil vegetation records.
Dr Teixeira said that as these ancient people travelled further east away from the homeland of southern Africa they met and mixed with at least four other groups of archaic humans.
The researchers proposed there was a mixing event in the vicinity of southern Asia between the modern humans and a group they have named ‘Extinct Hominin 1’.
Ancestors of Australo-Papuan people today mated with the species in modern-day Sunda and a distinct crossover happened in the Philippines.
In East Asia, a subsequent introgression with a Denisovan group closely related to the Altai specimen also appears to have taken place near the Denisova cave.
Researchers are also fairly certain humans interbred with another unidentified hominid, dubbed ‘Extinct Hominin 2’, around the island of Flores.
This species is different to any known human ancestor group, including those from Flores, known for their diminutive stature, known as Homo floresiensis.
Two of the archaic groups are currently known – the Neandertals and their sister group the Denisovans from Asia. But researchers, from the University of Adelaide’s Australian Centre for Ancient DNA, have detected traces of their DNA which survives in modern populations
‘Island Southeast Asia was already a crowded place when what we call modern humans first reached the region just before 50,000 years ago,’ said Dr Teixeira.
‘At least three other archaic human groups appear to have occupied the area, and the ancestors of modern humans mixed with them before the archaic humans became extinct.’
He said that groups in Asia were likely living in relative isolation from each other for hundreds of thousands of years before the ancestors of modern humans arrived.
‘The timing also makes it look like the arrival of modern humans was followed quickly by the demise of the archaic human groups in each area.’
The research was published in PNAS.
WHO WERE THE NEANDERTHALS?
The Neanderthals were a close human ancestor that mysteriously died out around 50,000 years ago.
The species lived in Africa with early humans for hundreds of millennia before moving across to Europe around 500,000 years ago.
They were later joined by humans taking the same journey some time in the past 100,000 years.
The Neanderthals were a cousin species of humans but not a direct ancestor – the two species split from a common ancestor – that perished around 50,000 years ago. Pictured is a Neanderthal museum exhibit
These were the original ‘cavemen’, historically thought to be dim-witted and brutish compared to modern humans.
In recent years though, and especially over the last decade, it has become increasingly apparent we’ve been selling Neanderthals short.
A growing body of evidence points to a more sophisticated and multi-talented kind of ‘caveman’ than anyone thought possible.
It now seems likely that Neanderthals buried their dead with the concept of an afterlife in mind.
Additionally, their diets and behaviour were surprisingly flexible.
They used body art such as pigments and beads, and they were the very first artists, with Neanderthal cave art (and symbolism) in Spain apparently predating the earliest modern human art by some 20,000 years.
Source: Read Full Article