Ecological flexibility, not tools or genes, explains why only one migration out of Africa succeeded around 50,000 years ago.
Today, all non-African people are believed to have descended from a small group that migrated into Eurasia roughly 50,000 years ago. However, fossil records show that many earlier migration attempts occurred before this time, none of which left a lasting genetic legacy in modern populations.
In a paper recently published in Nature, researchers offer the first clear explanation for why these earlier migrations failed. A team led by Professor Eleanor Scerri of the Max Planck Institute of Geoanthropology in Germany and Professor Andrea Manica of the University of Cambridge discovered that before the successful expansion into Eurasia, humans in Africa had started using a wider variety of habitats in new and unprecedented ways.
“We assembled a dataset of archaeological sites and environmental information covering the last 120 thousand years in Africa. We used methods developed in ecology to understand changes in human environmental niches, the habitats humans can use and thrive in, during this time,” says Dr Emily Hallett of Loyola University Chicago, co-lead author of the study.
Human niche expansion from 70,000 years ago
“Our results showed that the human niche began to expand significantly from 70 thousand years ago, and that this expansion was driven by humans increasing their use of diverse habitat types, from forests to arid deserts,” adds Dr Michela Leonardi of London’s Natural History Museum, the study’s other lead author.
“This is a key result,” explains Professor Manica, “Previous dispersals seem to have happened during particularly favorable windows of increased rainfall in the Saharo-Arabian desert belt, thus creating ‘green corridors’ for people to move into Eurasia. However, around 70,000-50,000 years ago, the easiest route out of Africa would have been more challenging than during previous periods, and yet this expansion was sizeable and ultimately successful.”
Flexibility, not tools or genes, ensured success
Many theories have been proposed to explain why the dispersal out of Africa around 50,000 years ago was uniquely successful. Some suggest it was due to new technologies or immunity gained through mixing with Eurasian hominins. However, no clear technological breakthroughs have been identified, and earlier admixture events do not seem to have helped earlier migrations succeed.
In this study, researchers show that humans significantly expanded the range of environments they could live in within Africa before migrating out. This broader ecological niche may have developed through increased contact and cultural exchange among groups, which helped break down geographic barriers and allowed people to thrive in more diverse landscapes.
“Unlike previous humans dispersing out of Africa, those human groups moving into Eurasia after ~60-50 thousand years ago were equipped with a distinctive ecological flexibility as a result of coping with climatically challenging habitats,” says Prof. Scerri, “This likely provided a key mechanism for the adaptive success of our species beyond their African homeland.”
Reference: “Major expansion in the human niche preceded out of Africa dispersal” by Emily Y. Hallett, Michela Leonardi, Jacopo Niccolò Cerasoni, Manuel Will, Robert Beyer, Mario Krapp, Andrew W. Kandel, Andrea Manica and Eleanor M. L. Scerri, 18 June 2025, Nature.
DOI: 10.1038/s41586-025-09154-0
The research was supported by funding from the Max Planck Society, European Research Council, and Leverhulme Trust.
Never miss a breakthrough: Join the SciTechDaily newsletter.
43 Comments
thank you
They left to get cigarettes and never came back.
H erectus seems to have done very well in getting around the world before 100 000 years ago. I suppose there were no stupid H saps to have got in the way!
And if the claims of the Australian Aborigines to have got to Australia 60 000 years ago are correct, then?
It is guesswork in order to retain jobs
Oh gee. As a wealthy white American, I wonder what happend to them? No way my great great great grandfather kidnapped and sold them.
You americans are all morons.
Thank you, I was going to say the same thing. This article needs to clarify. I guess Australian aboriginal people don’t count as humans now?
Bob, the claim of humans reaching Australia 60,000+ years ago has only scant evidence, whereas 50,000 to 48,000 years ago has a lot more credibility at this time, according to Australia.museum
Aboriginals arrived in Australia after the pygmy people, Aboriginals originated from Indonesia, Papua New Guinea amongst other places, probably 5/6 thousand years ago when the land bridges were in place ,the first black Africans walked down to Tasmania , totally different people to mainland Aboriginals, They were so primitive when the colonials arrived ,infanticide was a common practice, , a harsh environment , the dingo is an Indian street dog. Dingos were treated better than the women Traders came for trepang and stayed, over 500 different tribes all warring,
And the Patupaiarehe into Aotea (new Zealand ).
This article contradicts itself as well as making no sense. Firstly says all non African humans came from Africa 50k years ago. Then it mentions possible immunity from interbreeding with Eurasian “hominids”, even though modern humans have been around for 300k years give or take. So there were already humans in Eurasia which destroys the theory that there weren’t. Secondly you appear to be forgetting the Australian aborigines who have been there for at least 60k years. I’m just a guy, you’re supposed to know what you’re talking about sheesh.
The article does say that African humans migrated to Eurasia before 50K years ago, but those migration attempts weren’t successful. (“fossil records show that many earlier migration attempts occurred before this time, none of which left a lasting genetic legacy in modern populations”)
This is why they reject “possible immunity” as one of reasons for the success of the migration of 50K years ago.
It is always good to talk and compare info so that we can in the long run learn more.
Australian Aborigines have Neanderthal genes. Interbreeding between modern humans out of Africa and Neanderthal now believed to have first occurred about 50,000 at most, years ago, in the Middle East. How they got to Australia prior to that, 15,000 years prior? The 65,000 is a political number, supported by doubtful archeological evidence. And it makes no sense, 65 or 40 why the obsession with 65.
What about Pangea? Why would Africa have been the only area that humans inhabited at that time? Also don’t believe in the species theory.
Gail, Pangea broke apart about 200 million years before humans existed.
Out of Africa has been thoroughly debunked by genetics. How can they still push this silly theory?
Absolutely agree!
Mark, by non-Africans, they are referring to modern Europeans, Asians, Polynesians, etc. All non-Africans today, descended from Africans originally. They also mean Homo Sapiens.
Before H Sapiens left Africa, H Erectus was already living in Eurasia for 1.5 million years, H Neanderthal was also living there for hundreds of thousands of years before us.
We, (H Sapiens), appear to have migrated out of Africa multiple times without long-term success. Only after we gained more experience living in different ecological areas within Africa do we seem to have had the ability to survive outside Africa about 50,000 years ago. During our migration into Eurasia, we met and mated with other human species.
The evidence for modern H Sapiens reaching Australia 60,000 years ago is actually weak. The real date is most likely 50,000 to 48,000 years ago.
Out of Africa has been debunked quite successfully via genetic testing.
I came here to say the same thing. Same with the big bang, both false theories are pushed much less in higher academia now. However, it appears that by the comments, not everyone got the memo. Modern Caucasians have zero genetic ties to anything African.
70,000 years ago? Didn’t the Toba supervolcano eruption happen around that time?
1. Isn’t it Survival of the Nastiest (not fittest)? Perhaps the ancestors of Eurasians were driven out of Africa by their peaceful neighbours. Modern humans seemed to have killed off the stronger, larger brained neanderthals/ denisovans afterall. Bronze age (beaker) people wiped out the indigenous males when they arrived in the UK a few thousand years ago.
2. I hear very ancient people (Mycenae) have been discovered in Crete recently; remains were hidden by landslides. So it’s possible that Indo-Europeans descended from them, not Africans. The ancient Greeks who eventually took over the island were outstanding innovators. Any linguists know which group they fall into?
As monkeys exist outside Africa, humans might have occurred in other places too.
Evolution is cruel, and ‘survival of the nastiest’ is not far from the truth. But then the winners write history and paint themselves as saints.
I’ll go you “like” a comment?
Marie, the Mycenaean civilisation existed 4000 to 3000 years ago. Thousands of years after Indo-Europeans were already established.
We are not genetically related to monkeys from outside Africa.
Bingo this is proved via genetics. Out of Africa has been debunked.
True to an extent however modern as well as ancient Africans use the most basic of tools (like using a large rock in place of a hammer). So even if the out of Africa theory was true (which it isn’t), the smarter group with a more developed brain will win against a stronger but less developed group. One has swords and the other has fists. As for the neanderthals being wiped out, from what little we know, they were indeed savage “people”. They have found evidence of them eating their own children and having high pitched voices. Both of which are creepy enough to excuse the complete annihilation of an entire group in the minds of another primitive group of people.
A set of lungs made of forest.
Funny how this came on my feed as I am currently reading the book “the death of evolution” and learning about all the guess works and falsification and outright lies, by “the experts”.
I agree with you
OBiwan, “the death of evolution” is itself a work of guess work, falsification and outright lies, by religious zealots who want you to join their church and pay a ten percent tithe out of your earnings for the rest of your life.
The theory of evolution has 150+ years of research and over two million peer reviewed papers to back it up. And the evidence is so overwhelming now that it can be called a scientific fact.
all intresting and enjoyable comments ! is there room for outside genetic manipulation ?
Tim Mccaffrey, by outside manipulation, you mean aliens? No evidence for that. There are conspiracy theorists trying to sell that idea based on pure conjecture.
Or do you mean outside of Africa? No evidence for that either. There are racists trying to sell that idea based on pure conjecture, also.
What they’ve written about is explained in the holy Bible.
Genesis 11:1-9 (KJV) And the whole earth was of one language, and of one speech.
And it came to pass, as they journeyed from the east, that they found a plain in the land of Shinar; and they dwelt there.
And they said one to another, Go to, let us make brick, and burn them throughly. And they had brick for stone, and slime had they for morter.
And they said, Go to, let us build us a city and a tower, whose top may reach unto heaven; and let us make us a name, lest we be scattered abroad upon the face of the whole earth.
And the LORD came down to see the city and the tower, which the children of men builded.
And the LORD said, Behold, the people is one, and they have all one language; and this they begin to do: and now nothing will be restrained from them, which they have imagined to do.
Go to, let us go down, and there confound their language, that they may not understand one another’s speech.
So the LORD scattered them abroad from thence upon the face of all the earth: and they left off to build the city.
Therefore is the name of it called Babel; because the LORD did there confound the language of all the earth: and from thence did the LORD scatter them abroad upon the face of all the earth.
This is when our God and Creator changed our languages and skin colors and spread humanity across the Earth. This accorded approximately 400 years after Noah’s flood. Most languages can be traced back to this event.
This can’t be right, Nonwhite didn’t exist in Eurasia or any place else at this time.
Eskillz, not sure where you got that idea from. White people came from black people, not the other way around.
Gilbert O’Sughrue, I don’t know anything this book “The Death of Evolution,” but are you suggesting that the Bible is also lies and conjecture written by religious zealots? I know what religious zealotry looks like, and the Bible isn’t it. Simply dismissing creation out of hand entirely is a reach.
Actually it’s not a reach at all. There is absolutely no evidence supporting the creation myth of the Bible. Unless you’re referring to another of the hundreds of creation myths from cultures all over the earth. Of course none of them have any supporting evidence either.
Whether the Bible was written by religious fanatics is still open for debate.
What is the Bible a written word by a invisible creator through man? Strange
The subtitle of the Bible should be “The Goatheard’s Guide to the Universe”
Relevant 2000 years ago is far from Relevant now put the bible down its obsolete now please
Africa is the cradle of mankind it is the homeland of homo erectus the father of eurasian hominins and africa still is the homeland for homo sapiens even for those who believe in the alien manipulation of hominins to genetically make modern man it had to jave happened on the africa savanna