5 ms·

> the ancestors of modern humans interbred with at least five different archaic human groups as they moved out of Africa and across Eurasia. Now I'm confused.

by deogeo 7y ago

> the ancestors of modern humans interbred with at least five different archaic human groups as they moved out of Africa and across Eurasia. Now I'm confused. Isn't the consensus that there are currently no distinct human races - the groupings are just social constructs? But from how they refer to 'different human groups' this was apparently not the case in the past, despite the fact they were able to interbreed? So at what point did this change?

dorfsmay 7y ago
The idea is that homo sapiens sapiens (us) is not the only descendant of homo erectus, and there are genetic proofs that we interbreed with Neanderthals for example: https://en.m.wikipedia.org/wiki/Neanderthal_genetics https://en.m.wikipedia.org/wiki/Neanderthal_genetics
mc32 7y ago
One thing I don't get but is interesting is that humans inhabited Indonesia, Australia and Melanesia way before humans populated Madagascar. Now, apparently there were land bridges to Indonesia at different times (but not Australia or Melanesia but those migrations happened later) but Madagascar is populated much, much later into historical times.
droithomme 7y ago
> at what point did this change Out of Africa has been disproven but it was the status quo for so long that many are having a hard time letting go. Current fact based on actual evidence is multiregional coemergence, previously hypothesis now reasonably theory. Many of us have Denosivan, Neanderthal, etc ancestors, DNA fact, all prior to the hypothetical single point emergence event, therefore even if the hypothetical single point emergence event of some group is correct it's not the full story.
- namenotrequired 7y ago
  But the vast majority of the DNA of the vast majority of us is Sapiens, from Africa, no? If not, do you have any sources?
  - flukus 7y ago
    Just last week was a 210,000 year old skull in Greece: https://www.abc.net.au/news/science/2019-07-11/modern-humans-in-eurasia-earlier/11296454 https://www.abc.net.au/news/science/2019-07-11/modern-humans... and there is a 310,00 year old one in Morocco: https://www.abc.net.au/news/science/2017-06-08/300-000-year-old-remains-pushes-back-origin-of-species/8594632 https://www.abc.net.au/news/science/2017-06-08/300-000-year-... . The second is in Africa but not where we thought modern humans originated from and combined both of them at least put some doubt on the timing of the out of africa model. I think there are some older ones in China too. Saying it's disproven is taking things way too far but it's getting very messy and DNA can only take us so far. My own uninformed wild guess: The out of africa population that came to dominance started out as a seafaring culture, this explains their rapid expansion along mostly coastal routes, making it to Australia just a few thousand years after leaving africa and giving them a competitive advantage over other groups.
    - mc32 7y ago
      Why wasn’t Madagascar inhabited till relatively recently is the disappearing was a marine endeavor?
      - flukus 7y ago
        When I say seafaring I still mean mainly coastal seafaring. Assuming they could Island hop through Comoros (if it existed) that's still an 1100KM trip compared to the less than 100KM to get into Australia and almost continuous land between there and Africa. Maybe wind and ocean patterns could explain some of it too.
        mc32 7y ago
        Madagascar is about 100 to 120 miles from the African continent. Not too different from Cuba to Florida. In the same ballpark. But, I hear what you're saying. Deep sea vessels vs littoral hugging vessels.
    - mannykannot 7y ago
phil248 7y ago
All living humans are Homo sapiens. That's the only species of humans that is not extinct and there are no recognized subspecies that are not extinct. Modern humans are categorized as a subspecies called Homo sapiens sapiens. But it's worth noting that the entire idea that there are or were any subspecies of Homo sapiens is debated. All other humans were extinct by around 10,000 to 15,000 years ago.
wyattpeak 7y ago
I think you're confusing races and species. There is very little genetic distinction between modern races, little enough that we wouldn't consider them separate subspecies in other animals, so neither do we in humans. This, combined with the fact that distantly related people are often grouped together (for example describing both Africans and Australian Aboriginals as 'black') is why race is often described as a social construct. There were in the past, however, different human-like species (we call them hominins). Neanderthals are the best-known of them. They were able to interbreed with humans, but apparently only with a very low success rate, hence we describe them as separate species.* This is similar to the way we describe horses and donkeys as separate species, despite the fact that they can very rarely produce fertile offspring[1]. All other species of hominin have since died out (it appears we outcompeted them as we moved into their territories), leaving only our species. *Some researchers, since they were marginally compatible, describe the different groups as subspecies rather than species. It's right on the line, and there's no obvious correct choice. [1] https://en.wikipedia.org/wiki/Mule#Fertility https://en.wikipedia.org/wiki/Mule#Fertility
mirimir 7y ago
Those weren't "races" (whatever that means) but subspecies, or ~species that were close enough to breed. As with several species of cats that can crossbreed.[0] Modern humans are all Homo sapiens. All other Homo species merged, and were killed, thousands of years ago. I don't think that any surviving Homo groups are distinct enough to be called subspecies. And the concept of "race" has been abused so thoroughly, as the justification for colonialism and slavery, that it's out of favor. But the fact remains that reduced interbreeding, through geographic and/or social constraints, does produce distinguishable populations. We could call them breeds, I suppose, as with dogs and cats. And if it went on for long enough, on the order of say 10^5-10^6 years, new species could emerge. 0) https://www.thesprucepets.com/hybrid-cat-breeds-4176576 https://www.thesprucepets.com/hybrid-cat-breeds-4176576
harshreality 7y ago
There are two partially distinct issues there: 1. Interbreeding of Homo Sapiens with various "archaic humans". See https://en.wikipedia.org/wiki/Interbreeding_between_archaic_and_modern_humans https://en.wikipedia.org/wiki/Interbreeding_between_archaic_... 2. Modern racial labels and genetic clusters. The second is one of those highly contentious topics. It's fair to say, though, that most distinct racial labels are not particularly well-aligned with different genetic clusters[1]. And although genetic clusters exist, identifying them doesn't have much utility outside of trying to map human history and lineage. The best objection to race might be that modern races are nothing but various often confusing mixes of earlier races, as civilizations and/or tribes conquered each other. Those earlier races in turn were also mixes of even earlier races. And that went all the way back to when it was Homo Sapiens interbreeding with archaic humans. And then there's the unfortunate tendency to confuse racial characteristics with culturally- and educationally- mediated characteristics. [1] https://en.wikipedia.org/wiki/Human_genetic_clustering https://en.wikipedia.org/wiki/Human_genetic_clustering
deleted 7y ago
[deleted]
08-15 7y ago
You don't need distinct races or even a precise definition of the term to find traces of migrations in the genome. If you start with a population[], partially isolate it into two subgroups, then mix them again after a while, you can already detect a different pattern in their genetic variation than had they remained a single population. [] Population geneticists have decided to talk about different populations, just to avoid the term "race". I think that's dumb. Instead of using an even more ill-defined term, they could just have defined race properly.

by deogeo 7y ago

dorfsmay 7y ago

The idea is that homo sapiens sapiens (us) is not the only descendant of homo erectus, and there are genetic proofs that we interbreed with Neanderthals for example: https://en.m.wikipedia.org/wiki/Neanderthal_genetics https://en.m.wikipedia.org/wiki/Neanderthal_genetics

mc32 7y ago

One thing I don't get but is interesting is that humans inhabited Indonesia, Australia and Melanesia way before humans populated Madagascar. Now, apparently there were land bridges to Indonesia at different times (but not Australia or Melanesia but those migrations happened later) but Madagascar is populated much, much later into historical times.

droithomme 7y ago

> at what point did this change Out of Africa has been disproven but it was the status quo for so long that many are having a hard time letting go. Current fact based on actual evidence is multiregional coemergence, previously hypothesis now reasonably theory. Many of us have Denosivan, Neanderthal, etc ancestors, DNA fact, all prior to the hypothetical single point emergence event, therefore even if the hypothetical single point emergence event of some group is correct it's not the full story.

namenotrequired 7y ago
But the vast majority of the DNA of the vast majority of us is Sapiens, from Africa, no? If not, do you have any sources?
- flukus 7y ago
  Just last week was a 210,000 year old skull in Greece: https://www.abc.net.au/news/science/2019-07-11/modern-humans-in-eurasia-earlier/11296454 https://www.abc.net.au/news/science/2019-07-11/modern-humans... and there is a 310,00 year old one in Morocco: https://www.abc.net.au/news/science/2017-06-08/300-000-year-old-remains-pushes-back-origin-of-species/8594632 https://www.abc.net.au/news/science/2017-06-08/300-000-year-... . The second is in Africa but not where we thought modern humans originated from and combined both of them at least put some doubt on the timing of the out of africa model. I think there are some older ones in China too. Saying it's disproven is taking things way too far but it's getting very messy and DNA can only take us so far. My own uninformed wild guess: The out of africa population that came to dominance started out as a seafaring culture, this explains their rapid expansion along mostly coastal routes, making it to Australia just a few thousand years after leaving africa and giving them a competitive advantage over other groups.
  - mc32 7y ago
    Why wasn’t Madagascar inhabited till relatively recently is the disappearing was a marine endeavor?
    - flukus 7y ago
      When I say seafaring I still mean mainly coastal seafaring. Assuming they could Island hop through Comoros (if it existed) that's still an 1100KM trip compared to the less than 100KM to get into Australia and almost continuous land between there and Africa. Maybe wind and ocean patterns could explain some of it too.
      - mc32 7y ago
        Madagascar is about 100 to 120 miles from the African continent. Not too different from Cuba to Florida. In the same ballpark. But, I hear what you're saying. Deep sea vessels vs littoral hugging vessels.
  - mannykannot 7y ago

phil248 7y ago

All living humans are Homo sapiens. That's the only species of humans that is not extinct and there are no recognized subspecies that are not extinct. Modern humans are categorized as a subspecies called Homo sapiens sapiens. But it's worth noting that the entire idea that there are or were any subspecies of Homo sapiens is debated. All other humans were extinct by around 10,000 to 15,000 years ago.

wyattpeak 7y ago

I think you're confusing races and species. There is very little genetic distinction between modern races, little enough that we wouldn't consider them separate subspecies in other animals, so neither do we in humans. This, combined with the fact that distantly related people are often grouped together (for example describing both Africans and Australian Aboriginals as 'black') is why race is often described as a social construct. There were in the past, however, different human-like species (we call them hominins). Neanderthals are the best-known of them. They were able to interbreed with humans, but apparently only with a very low success rate, hence we describe them as separate species.* This is similar to the way we describe horses and donkeys as separate species, despite the fact that they can very rarely produce fertile offspring[1]. All other species of hominin have since died out (it appears we outcompeted them as we moved into their territories), leaving only our species. *Some researchers, since they were marginally compatible, describe the different groups as subspecies rather than species. It's right on the line, and there's no obvious correct choice. [1] https://en.wikipedia.org/wiki/Mule#Fertility https://en.wikipedia.org/wiki/Mule#Fertility

mirimir 7y ago

Those weren't "races" (whatever that means) but subspecies, or ~species that were close enough to breed. As with several species of cats that can crossbreed.[0] Modern humans are all Homo sapiens. All other Homo species merged, and were killed, thousands of years ago. I don't think that any surviving Homo groups are distinct enough to be called subspecies. And the concept of "race" has been abused so thoroughly, as the justification for colonialism and slavery, that it's out of favor. But the fact remains that reduced interbreeding, through geographic and/or social constraints, does produce distinguishable populations. We could call them breeds, I suppose, as with dogs and cats. And if it went on for long enough, on the order of say 10^5-10^6 years, new species could emerge. 0) https://www.thesprucepets.com/hybrid-cat-breeds-4176576 https://www.thesprucepets.com/hybrid-cat-breeds-4176576

harshreality 7y ago

There are two partially distinct issues there: 1. Interbreeding of Homo Sapiens with various "archaic humans". See https://en.wikipedia.org/wiki/Interbreeding_between_archaic_and_modern_humans https://en.wikipedia.org/wiki/Interbreeding_between_archaic_... 2. Modern racial labels and genetic clusters. The second is one of those highly contentious topics. It's fair to say, though, that most distinct racial labels are not particularly well-aligned with different genetic clusters[1]. And although genetic clusters exist, identifying them doesn't have much utility outside of trying to map human history and lineage. The best objection to race might be that modern races are nothing but various often confusing mixes of earlier races, as civilizations and/or tribes conquered each other. Those earlier races in turn were also mixes of even earlier races. And that went all the way back to when it was Homo Sapiens interbreeding with archaic humans. And then there's the unfortunate tendency to confuse racial characteristics with culturally- and educationally- mediated characteristics. [1] https://en.wikipedia.org/wiki/Human_genetic_clustering https://en.wikipedia.org/wiki/Human_genetic_clustering

deleted 7y ago

[deleted]

08-15 7y ago

You don't need distinct races or even a precise definition of the term to find traces of migrations in the genome. If you start with a population[], partially isolate it into two subgroups, then mix them again after a while, you can already detect a different pattern in their genetic variation than had they remained a single population. [] Population geneticists have decided to talk about different populations, just to avoid the term "race". I think that's dumb. Instead of using an even more ill-defined term, they could just have defined race properly.