Out of Africa: celebrating 100 years of human-origins research
nature.com
nature.com
Neanderthals were highly inbred and had low population numbers. Being a carrier of this form of CAH would have absolutely kept the population numbers low all by itself as getting two copies would have been nonviable. Further Neanderthals are most known for contributing to human specific DNA sets such as improved immune system. Here we have something that even in the non classic form is havoc with the HPA-Axis and give incredible evolutionary pressure to resolve, one way is to simply dramatically improve the immune system.
As far as I can tell this hasn't been written about before. Lots of stuff like this will be noticed and or figured out in the decades ahead.
For example you can spend your career mapping hundreds of small-effect variants linked to intelligence or phenotypes that lead to increased likelihood of certain behaviours.
You can even publish a study showing that people who carry a certain gene variant and experienced childhood neglect have “increased risk of committing severe, impulsive, violent recidivist crimes”, and that the variant is more prevalent in prison populations than the general public in a certain region.
You can also publish a population genetics study showing that humans have relatively easily computed genetic structure (see: 23andMe ancestry) because countless alleles are practically fixed in certain populations relative to others due to selection or founder effects, or are prevalent enough that if you have a segment of your genome with enough of them them you must have had an ancestor from a certain region.
What you can’t do is combine these concepts into any uncomfortable findings when it comes to humans.
Apparently, they’re also hard to plainly state on an anonymous forum as well. Weird.
I think it's even deeper than confusing cause and effect.
I mean, maybe I'm missing some information, but the comment says:
a study showing that people who carry a certain gene variant and experienced childhood neglect have “increased risk of committing severe, impulsive, violent recidivist crimes”
The potential fundamental error there is the whole multiple independent variable thing. The study was likely designed from the outset without regard to the fundamentals of the scientific method. Which is a bigger issue than just confusing cause and effect. It gives other scientists a suspicion that the people doing the study aren't even aware of the potential confounding nature of the design?
The people doing the study will of course call the "snobbish" scientists "anti-racists" for pointing these things out. But scientists are neither "racist" nor "anti-racist". The conclusions follow from the data via the scientific method, or the conclusions don't follow. A good scientist will not presume, a priori, what the conclusions are. In this instance, scientists can be forgiven for concluding that the findings don't follow.
Scientists are better described as Scientific Method Fundamentalists. If they believe in anything, it is the scientific method. Everything else? Well, yeah, you will need to convince them. The good news is you can do that, but you have to use the scientific method to do so. If you don't, they rightfully dismiss you out of hand.
I think the people who push these studies are misunderstanding the dismissal of their "findings" as antagonism to their conclusions. And on the other side, there are probably scientists who are not even bothering to explain the nature of their problem to them. There's probably a sense of, "It's a waste of time to talk to them", on both sides.
Oh yeah, you will definitely need to assume that!
We know quite well that some traits are concentrated in a single place or two: marathon winners come disproportionately from the Rift Valley in Kenya, sickle cell disease is mostly a West African trait and Tay-Sachs disease is concentrated among the Ashkenazim.
Few people dispute the above. The really controversial question is whether there are any such differences from the neck up, so to say.
To insist that nobody should look into it because what they might find could upset you is just bizarre.
Overlapping normal distribution, yes, but slightly different means, well within a standard deviation seems to be overconfident.
"Therefore you still have to treat people as individuals because the ancestry provides little signal."
No contest here.
"So then why is there so much interest among skeptical, contrarian, anti-woke, scientific racism types on this question?"
Because the difference at the extremes would be significant, and would explain overrepresentation and underrepresentation of certain groups among, say, top scientists.
The competing hypothesis, which explains differences among groups by discrimination and/or poverty, doesn't fully explain why heavily persecuted groups such as Jewish or Vietnamese refugees still manage an academic rebound within a generation or so of arriving into safety, even though they are still targeted by racial hatred. Taken globally or even just in the US, the correlation between academic success and persecution/power status is weak enough that it makes people doubt the "discrimination/poverty" explanation and motivates them to seek alternatives.
It depends if we talk about means or tail ends. The GP post referred to marathon runners, presumably winning marathon runners, even within the Rift Valley in Kenya don't get selected from the mean of the population but from the tail-end. So, while there isn't much of a difference for means between runners in Albania and Kenya, when we look at tail end we might find very large differences.
Same thing for any case where is a selection process. If you have any "top-X" selection involved, then looking at means is a bit more confusing.
> Therefore you still have to treat people as individuals because the ancestry provides little signal
Hmm, I don't see here people anyone arguing not treating people as individuals. Of course we have to treat people as individuals. But not sure how that contradicts looking a distribution of traits, features, disease markers, etc.
Maybe you're arguing for or against some point the GP poster made. I was mainly saying relying on means in the particular example doesn't seem to work. I was helping you out! If you wanted to refute GP's point you could have said, "here marathon runners statistics doesn't quite apply".
Yeah I know "the means are closer to each other than the standard deviation" is the "standard" (pun intended) thing that high school and college kids get about difference between men vs women and other population characteristics and you're trying to make a very good point, but it just doesn't always apply and sometimes repeating it when it doesn't apply, instead of convincing people, could end up confusing them.
Your reflexive dismissal of something that’s not only factual but wouldn’t be controversial about any vertebrate except humans is exactly what I was alluding to.
I though ancestry reports were regarded as unreliable to the point of meaninglessness because the genes used were not sufficiently strong indicators of population?
> Presumably because racists would ignore all the mediating environmental factors or vastly misrepresent the proportion of variance explained by a given genotype.
Not discussing something because people can misrepresent it is a bad idea. it is both wrong, and has the opposite effect to that intended because it lends credibility to claims of cover up.
Most people don’t necessarily understand recombination and that if three of your grandparents are Danish and one of your grandparents is, Italian, then you are going to be on average 25% Italian… but that it’s also a distribution centred around 25%. By luck of the draw you could be 3% or you could be 45% Italian genome-wise. People might base their identity on being 1/4 this or 1/8 that, and be upset when an ancestry report gives the actual %.
You can see this by looking at genes with observable consequences such as lactose tolerance. While there are multiple genes for this AFAIK, the commonest is spread over a huge area.
Something as specific as "Danish" or "Italian" genes looks illusory.
0: https://en.m.wikipedia.org/wiki/Mainstream_Science_on_Intell... an editorial written to tell the public that this is not some shocking, fringe claim. You can follow links from the page for the full text.
There are still papers being written about how those analyses were flawed: https://www.pnas.org/doi/abs/10.1073/pnas.2319496121
A common refrain among non religious people is that religion is false, self contradictory, or something similar.
And yet the large overlap between these people and anti-racists cannot face the evidence that evolution applies to humans, and that genetic differences can have measurable effects. This becomes a core tenent of their (un)beliefs, that somehow we are all equal in construction, AND that evolution is real. Two completely incompatible beliefs (or concepts, if you can't stand such a word).
Prevalence of the MAOA gene is quite interesting indeed.
To expand upon that a bit, one deeply held belief is that Racism is wrong, not just morally but factually, that we are all exactly equal in nature. That our only differences come from nurture. The other belief (or "non-skeptically accepted prospect") is that humanity has evolved, first from africa, then in disparate populations spread over the entire land area of the earth, being subject to many varied natural environments and thus selections. Such natural selections MUST select for different traits, often wildly different. Such traits cannot be contained to "skin color only" a meaningless, arbitrary restriction.
I’m not sure how “racism is bad” requires the idea that “we are all equal by nature”.
“Racism is bad” means that the law should treat us equally and that you should not treat people differently based solely on their skin color.
So if you see that e.g. one group is lagging behind in math then that is taken at face value as evidence that 'math is racist.' A search for that exact phrase will turn up a million hits, pushed by some very big entities, if you want to go down this rabbit hole.
But if you don't already know about this stuff - just don't. The amount of stupidity and transparent divide+conquer politics in it all is just nauseating.
On the other hand it does have contemporary relevance as a lot of the funding for this stuff is being scrapped, and it's nice to understand what we're 'losing.'
But the ties to racism do seem inane and more to do with outrage culture becoming the norm after the social media explosion. It’s unfortunate.
Anyone doing actual science cannot determine whether you are worth hiring based on your DNA - all they can do is point to some correlations which don't tell them about you individually. It is quite possible for such research to be discredited in future by other studies.
It's not even well defined what are all the characteristics that make a good "X" to then discriminate about because people of all kinds end up doing things we didn't expect them to be able to. What is intelligence and how many ways are there of measuring it and what kind does a certain job require anyhow?
So it is factually and morally wrong to discriminate on DNA. It might be pointless to say this though, as I notice that to convert a prejudiced person into an anti-racist all you have to do is make them think they're being discriminated against.
The big mistake that racists and bigots make is in overvaluing whatever they think their own strengths are and undervaluing strengths they don't have.
Of course giving the government the right to prevent some individuals from having children is an extremely slippery slope. States that are willing and capable of engaging in such things e.g. ( Communist China back in the 70s ) also tend to be run by extremely misguided and delusional people.
Since we can do gene therapy to some degree already I imagine we'll fix things that are already known health problems for an individual.
Eventually other things will become possible, including modifications that are not about health. That's where dragons be. We'll at least need rules about modifications that aren't 99% understood and "guaranteed" to do what is wanted. We will also want to ensure some level of genetic diversity - not allowing everyone to make their kids blue eyed.
If I was to take this to the logical end, you can bar any bananas, lizards, dogs, or other non humans by simply looking at their DNA and having no other applicant specific information.
To bring this back to the more mundane, even the BBC is covering whether genes impact your likelihood to have certain hobbies. We are not going to discover that genes impact our lives LESS as we dig into the human genome more. To proclaim by personal fiat that people will never figure out how to productively (and for personal/corporate gain) filter by DNA is simply wrong.
This is similar to the idea that criminals with 20 previous felonies can be given any punishment besides life in prison or death. It is really super easy to predict the future of any such criminal let loose. A 90% chance of a 21st felony and yet another ruined or ended life.
[1] https://www.bbc.com/future/article/20230509-how-genetics-det...
This is a strawman of the real understanding that humans, as a species, have extremely low genetic diversity. Along with that, variations within a population are larger than variations between populations. In addition, there are countless confounding factors that play a larger role. Lastly, teasing out actual cause and effect is incredibly difficult. “Anti-racist” scientists simply understand to not take simplistic, reductive interpretations and jump to conclusions trying to get easy answers to complex situations.
That doesn’t really change anything, though. That low variance still might allow (and well.. obviously does) enough space for significant genetics differences (that impact everything ranging from physical properties to intelligence) between individuals or subgroups to manifest themselves.
In theory we could certainly produce a “breed” of extremely physically fit “super-humans”. Same probably applies to other traits. Not that anyone should be ever allowed under any circumstances to try something like that.
With modern understanding of genetics eugenics would be more or less scientifically sound on paper (of course a dystopian society which regulates human breeding would be a horrible place to exist in even if it was made up of objectively “genetically superior” individuals)
In France the official dogma of the educated is that every difference is cultural, and races don't exist. My father for example strongly held and defend those beliefs. Somehow he gets very angry when I ask why there is wide academic achievement difference between his children despite growing in the same environment, or how Japanese people could instantly guess I'm a foreigner while not uttering a single words. I think that deep down all those people know the truth but they don't want to admit it, nor admit it to other for fear of the social consequences.
Why are there wide academic achievement differences between children who have the same "race" who grow up in the same environment? According to you, this should not be the case.
> how Japanese people could instantly guess I'm a foreigner while not uttering a single words
Do you think they can do so for any given person? I guarantee you there are foreign people who Japanese people don't guess are foreign, and non-foreign people who Japanese people guess are foreign. How can this be?
I can sympathize with your father getting angry. Considering how trivial it is to come up with counter arguments, it must be frustrating to have this brought up more than once.
Same environment, different genes = educational performance gap.
Do they exist in a scientifically viable way?
Most of the definitions around race are tied to a subjective view of a person’s physical appearance.
Is Obama (the son of a black Kenyan man and a white American woman) black or white? If neither, what is this new race to be called? Would he be a different race if his father was also mixed race?
I find that often times asking people this question leads us back to something akin to the one-drop rule and I don’t see any value in that.
American racists had precise, and now-offensive nomenclature for rations all the way down to 1/8 black, possibly beyond. https://www.pbs.org/wgbh/pages/frontline/shows/jefferson/mix...
Wait, I thought your argument is that intelligence this is genetic - what then explains the variation among siblings, according to your worldview?
If your goal is to show that the gene variant causes violence, you probably need to compare violent vs nonviolent prison populations, not prison populations vs general public. We already know that there are aspects of genetics that affect likelihood of being imprisoned, all else being equal.
Some topics are more likely to attract assholes than others. If you don't want to be drawn into a political debate with assholes, you don't study those topics. Better to study something that can be studied without being forced to make a political stand.
That would not happen in the ideal world, where people try to avoid misinterpreting and overgeneralizing results. But controversial topics always attract people acting in bad faith. Even most of those acting in good faith are unused to the level of precision and pedantry required to make justified conclusions from data.
Race as we culturally define it (which varies significantly over time and location) doesn't respresent differences in fact, but rather the things that are most obvious to our perception - e.g., skin color. There's no coincidence that what we see most easily - skin color - is somehow a strong indicator.
It's also a misunderstanding of statistics to think that differences will apply to individuals. These aren't two completely separate distributions, but rather distributions that overlap in different ways for different factors that impact outcomes in complicated an often unknown ways. Science and genetics are not that simple.
> That would not happen in the ideal world
Our world is far from that, sadly. What has caused more damage in history than racism - wars, massacres, slavery, oppression (including mass incarceration), endless lifetimes and generations lost to neglect? There have been no wars, slavery, or massacres due to anti-racism.
They go "hey, cool, we can get a paper out of this" https://web.mit.edu/fustflum/documents/papers/AshkenaziIQ.jb...
History has shown this to be wise. If human beings -- as individuals or as a group -- come to view themselves as superior to others, the next step is always abuse, enslavement, or war. Civilization tries very hard to suppress this for the same reason that it suppresses some of the wilder expressions of unbridled human sexuality, physical aggression, etc. Moral issues aside, there’s certain stuff that just breaks everything if you let it run unchecked.
A truly intelligent being could look dispassionately at the various distributions of abilities and other differences in its population and deal with this maturely and rationally. We aren't capable of this yet. I don’t think we can handle it emotionally.
This is an area where my opinions have evolved as I’ve gotten older and seen more of the world. We do, in fact, need taboos around certain things. I don’t think there should be too many of them, but there’s areas where the need has been repeatedly demonstrated.
More generally, any characteristic that can be used to denigrate (or promote) a group is not inheritable. It's the fiction that keeps genetics moving along.
… are all highly heritable.
Humans are miraculously, according to the experts, the sole and unquestionable exception in the animal kingdom.
I don’t know enough about it to say whether the studies are BS or not, but as an experienced animal keeper, claims that it’s not heritable goes so heavily against my lived experience that I can’t reconcile it with reality.
You can[1], and it's been done.
If we're renaming things I'd rather we call ourselves homo gregarius. There's no evidence we were individually smarter than our Neanderthals cousins, rather we were a variety of humans which lived in larger groups and thus could sustain a more sophisticated technological toolkit.
"Kindred: Neanderthal Life, Love, Death and Art" by Rebecca Wragg-Sykes is great.
"Almost Human" by Lee Berger is about one particular discovery rather than human origins as a whole but is an entertaining read - there was an accompanying PBS special (NOVA?) that's worth watching as well to really understand the scale of some of the caves they were in.
After all, if humans were randomly distributed on planet Earth according to the local environment's carrying capacity, 100 000 years later Id expect to find a lot more human remains in Eritrea than the Pontine marshes.
Anyway, multiple concurrent lines of evidence. You're morphologically similar to ancient African ancestors. The serial founder effect points to Africa. Molecular clocks point to Africa. Fossil evidence points to Africa.
Anthropologists don't think anatomically modern humans originated exclusively in the places with the most fossils though. That's just where we find the most fossils.
They could now argue that Out of Africa was in fact proof of the superiority of whites, who had clearly evolved since leaving Southern Africa. Of course, any evidence that this is not the case can be ignored, keeping the true core of the research programme intact.
Oh, and "socially correct" is a thought terminating cliche. You clearly meant "politically correct" but that has such a negative valance that you need to change one of the words to not sound conspiratorial.
Only crackpots and religious nuts are supporting alternatives.
I think you may be talking about the ADOS people who believe all sorts of conspiracy theories like that, but are not a religious group at all. However they do believe black Christians and black Muslims are following the "white man's" religions. In any case, their beliefs would mean the ADOS nutjobs are technically "crackpots", as the initial post indicated, rather than a "tribe".
Not really, and most Muslims would dispute that the Nation of Islam is Islam.
The Nation of Islam is essentially a newly invented religion from the early 1900s. It has its own extensive Sci-Fi mythology (including the Yakub story) that is pretty much entirely different from Islam, though it borrows some aspects of Islam. It's heavily influenced by Black Nationalism and Pan-Africanism.
Not according to mainstream Muslims.
Put it on your med school applications too when submitting MCAT scores.
The white colonizer did not get colonized by tribes in Africa.
>> Genetic studies have put an end to that kind of speculation. Only crackpots and religious nuts are supporting alternatives.
David Reich (author of "Who We Are and How We Got Here: Ancient DNA and the new science of the human past") says[^0]:
" The modern human lineage, leading to the great majority of the ancestors of people today, was probably in sub-Saharan Africa for the last 500,000 years at least. It might be much more. Certainly our main lineage was in Africa, probably 3-7 million years ago.
But in a period between about 2 million to 500,000 years ago, it's not at all clear where the main ancestors leading to modern humans were. There were humans throughout many parts of Eurasia and Africa with a parallel increase in brain size and not obviously closer ancestrality to modern humans in one place than in the other. It's not clear where the main lineages were. Maybe they were in both places and mixed to form the lineages that gave rise to people today.
There's been an assumption where Africa's been at the center of everything for many millions of years. Certainly it's been absolutely central at many periods in human history. But in this key period when a lot of important changes happen—when modern humans develop from Homo habilis and Homo erectus all the way to Homo heidelbergensis and the shared ancestor of Neanderthals, modern humans, and Denisovans— that time period which is when a lot of the important change happened, it's not clear, based on the archaeology and genetics, where that occurred as I understand it. " (emphasis mine throughout)
---
That's a time period before homo sapiens, not after.
"people often find it hard to accept the findings and much preferred the multi-regional hypothesis"
Other systems of racism can also tied to some sort of belief in separate origins - caste in India.
Ancient Fossil Evidence Outside Africa – Fossil remains predating the supposed OOA migration (~60,000 years ago) have been found in China (Dali skull, 260,000 years old), Greece (Apidima 1, 210,000 years old), and the Levant (Misliya jaw, ~177,000 years old), suggesting Homo sapiens or proto-sapiens were present outside Africa long before the mainstream migration timeline.
Genetic Discrepancies – Some non-African populations (e.g., Australo-Melanesians and East Asians) possess archaic DNA from unknown hominins not found in Africans, implying deep regional continuity rather than a complete replacement by recent African migrants.
Multiple Ancestral Lineages – The discovery of distinct ancient hominin populations, such as the Denisovans and Red Deer Cave people, suggests a complex web of interbreeding rather than a single-origin replacement model.
Stone Tool Continuity in Asia – The presence of advanced stone tools in Asia (e.g., at Jwalapuram, India, ~74,000 years ago) suggests technological continuity rather than a disruption expected from an OOA replacement event.
MtDNA & Y-Chromosome Inconsistencies – While mitochondrial DNA (mtDNA) is often cited in support of OOA, recent studies indicate that some deep-rooted Y-chromosome lineages (e.g., haplogroup D found in Tibetans and Andamanese) show ancient divergence outside Africa, inconsistent with a recent African bottleneck.
Early Human Artifacts in the Americas – Artifacts and footprints in the Americas (e.g., White Sands, ~21,000–23,000 years ago) suggest a much earlier presence of humans, challenging the late migration model and implying deeper population history.
Human evolution and migration were likely far more complex than a single, recent dispersal from Africa. The evidence supports alternative models such as multiregional evolution or earlier, undocumented migrations.
We are of course fully aware of much earlier migrations of pre-Sapiens populations of Erectus and probably others. There's no controversy there, except in believing that these populations were ancestral to the current population.
That Australo-Melanesian and East Asian people possess a small amount of genes from archaic populations is also not controversial. They have genes from Denisovans, no issue there, most people outside of Africa also have a little Neanderthal DNA. There also seems to be remains of some unknown earlier homo, again that is in no way contradicting an African ancestry (out of Africa). It simply means that we don't know where or when all earlier homo species were.
Exactly when the "final" migration out of Africa happened is still not entirely clear. If it is 60000 (earlier suggestions have been 50k and even earlier, which was proved wrong) of somewhat earlier isn't yet set in stone. That doesn't change the actual pattern.
White Sands and what / when immigration to the Americas happened is in this context extremely late and is really irrelevant.
At this point the main hypothesis is that there was an Out of Africa event, and that the migrating people to some extent interbred with earlier migrations (specifically Neanderthals and Denisovans, and possibly some other yet unknown split from the ancestors of the two latter). That there was an acquisition of those extra genes is something new from the last few decades, but this really has zero to do with supporting a multi-regional hypothesis. If nothing else, the genetic evidence when looking at DNA from people from absolutely any place in the world is so overwhelming that there's no question at all. We even see the pre-migration genetic bottleneck - two people from opposite sides of the world have less genetic variation between them than the genetic variation between two chimpanzees from different sides of a river in a single forest.
That is contradicted by the findings below.
Genetic Discrepancies – Some non-African populations (e.g., Australo-Melanesians and East Asians) possess archaic DNA from unknown hominins not found in Africans, implying deep regional continuity rather than a complete replacement by recent African migrants.
Multiple Ancestral Lineages – The discovery of distinct ancient hominin populations, such as the Denisovans and Red Deer Cave people, suggests a complex web of interbreeding rather than a single-origin replacement model.
MtDNA & Y-Chromosome Inconsistencies – While mitochondrial DNA (mtDNA) is often cited in support of OOA, recent studies indicate that some deep-rooted Y-chromosome lineages (e.g., haplogroup D found in Tibetans and Andamanese) show ancient divergence outside Africa, inconsistent with a recent African bottleneck.
If Homo sapiens left Africa ~60,000 years ago, why do we find fossils in China that are 260,000 years old? In Greece we found 210,000 years old fossils, and the Levant at 177,000 years old? These predate the major OOA migration and suggest independent regional evolution.
Non-African populations, especially Australo-Melanesians, carry archaic DNA not found in Africans. Where did that archaic DNA originate? It was not Africa. Again, this shows a regional continuity rather than a simple migration-plus-interbreeding scenario.
If an African bottleneck occurred, why do we see deeply divergent lineages like Y-DNA haplogroup D in Tibetans and Andamanese? These suggest lineages of non-African ancestry survived bottlenecks.
Stone tools in India ~74,000 years ago show no signs of disruption, contradicting the idea that a major migration replaced existing populations.
The OOA model does not fully explain this evidence. A more nuanced model including persistent non-African lineages is the only thing that makes sense.
I can't see anything in what you listed which is different from Out of Africa, plus a little intermixing with earlier migrations (e.g. Neanderthals and Denisovans, and potentially others). That would fully explain why you see some "old" DNA in some populations. It's still Out of Africa, again because 96-98 % of the DNA of any person on Earth is from a (relatively) recent exodus out of Africa. This is still extremely different from the older multi-regional hypotheses.
0. https://en.wikipedia.org/wiki/Proto-Indo-European_homeland