7 ms·

The only hypothesis I can come up with that lets me square the archaeological evidence (the numerous sites with pre-clovis dates) and the genetic evidence (almo

The only hypothesis I can come up with that lets me square the archaeological evidence (the numerous sites with pre-clovis dates) and the genetic evidence (almost all current North American indigenous population genetics derives from a single population that split off 17Kya) is that there's been multiple waves of people that have migrated into the Americas, and that either the events precluding or surrounding the Younger Dryas period contributed to a severe depopulating of the continent at that time, or that the most recent wave of immigrants almost entirely wiped out the previous population, as had they absorbed them I would assume we'd see more genetic evidence of that. Personally I think the preponderance of archaeological evidence is strongly suggesting that there were absolutely people in the Americas pre-clovis, but the really interesting question from here then is who were they and what happened to them?

AlotOfReading 4y ago
The 16-17ka date is the divergence between Northern and southern native american groups, both related to the later (~13ka) clovis culture. Indigenous americans as a whole diverged from Eurasians sometime before 20ka. That initial population eventually split into multiple lineages (Unsampled Population A, Ancient Beringians, Clovis ancestors) that entered the Americas, although it's not clear what order those events occurred in. We know that there was also later admixture between Alaskan and Eurasian populations across the bering strait and groups like the paleoinuit likely originated (partially) on the siberian side of the straight, but the vast majority of indigenous ancestry across the Americas as a whole derives to the ancestors of the clovis complex. It's not clear how preclovis people relate genetically to those clovis ancestors in the absence of genetic data for them.
crazygringo 4y ago
Yes, multiple waves is suggested near the very end of the article, and that this is a focus of current data collection: > Another possibility ties together evidence of Population Y and potential archaeological evidence at sites like White Sands. Could there have been multiple migrations into the Americas, with one pre-LGM migration consisting of Population Y individuals (and perhaps Unsampled Population A or other groups we have yet to identify), and one post-LGM migration? This would reconcile the archaeological evidence of early traces of humans in the Americas (if they are indeed legitimate, which has yet to be demonstrated to everyone’s satisfaction) and the genetic data. > Archaeologists sceptical of White Sands’ early dates are dubious of the second scenario, and it is admittedly speculative. We need a great deal more data, both genomic and archaeological, to test it. But, as a field, we are actively engaged in collecting that data, even as I type these words.
moloch-hai 4y ago
The comet strike of 12,800 years ago neatly wiped out north American camels, horses, giant sloths, mammoths, mastodons, saber-tooth cats, dire wolves, the biggest bear and bison, cheetahs, and numerous other species, and neatly terminated all Clovis production. It would not be a stretch to guess it also wiped out most of the people making the Clovis points. People living in southeast Asia 70,000 years ago were certainly sailing out of sight of land, because they reached and colonized Australia. It beggars belief to suggest they did not also go to other places in equally easy reach, and then others from there. The article disgracefully trots out, once again, the "construction equipment" claim about the Cerutti mastodon site, despite its thorough refutation. The article further vindicates Graham Hancock's complaints of vicious mis-representation. His projections are certainly wrong in myriad details, but he is totally sincere in advancing them. He has predicted, correctly, embarrassingly many recent developments historians laughably insisted were impossible; I would not be surprised at more. When you feel you need to lie about your opponent to discredit him, it tells us more about you than about him. Genetic evidence, and notions of a more-or-less constant rate of accumulation of mutations, are on much shakier ground than the author suggests. That unreliability is unfortunate for people obliged to rely on it. We can still learn a great deal from it about the order of migrations, but not so much their dates relative to geological events.
- EdwardDiego 4y ago
  Comet strike?
  - jcranmer 4y ago
    There's a theory that the Younger Dryas was caused by an impact of a bolide on a North American glacier, usually of one that fragmented considerably on entry.
    - moloch-hai 4y ago
      There was certainly a bolide strike roughly coincident with the beginning of the 1300-year Younger Dryas cold spell. Whether the strike caused the Younger Dryas cold spell is a matter of speculation. We can anyway be confident that the cold spell did not cause the bolide strike.
jcranmer 4y ago
There is I think a little bit of chronological confusion that I will try to clear up. My understanding of the consensus rough chronology is as follows: * Populations move into Beringia maybe 20-25kya. (My knowledge of this date is particularly hazy). * Populations start moving from Beringia into the Americas. This date is highly contested, but it's accepted that this occurred at least 15kya. * Clovis culture starts up around 13kya, ends around 11.5kya. * Younger Dryas starts up 12.8kya, ends around 11.5kya. So genetic evidence suggesting that peopling starts from around 17kya isn't inconsistent with mainstream dates for peopling of Americas, although it would mean being suspicious of sites much older than 17kya. > but the really interesting question from here then is who were they and what happened to them? My interpretation of the evidence... they became Clovis culture.
- moloch-hai 4y ago
  The lakebed footprints securely scotch that timeline, and Cerutti blasts it to smithereens. The most that could be left of it is that these late migrations somehow wholly supplanted earlier populations. Either the earlier pop. died out before the later crew arrived, or ... well, genocide is a demonstrated human behavior. It is hard to carry out continent-wide without microbial assistance, but they could have had that.
  - acdha 4y ago
    It’s cool to be excited about this - who wouldn’t be? - but you’re using very definitive language for highly speculative. The article outlines a timeline which, as with the post you’re replying to, is compatible with the White Sands lake footprints. The Cerutti site _could_ completely upset that theory but it’s far from proven that it’s not a misunderstanding, or that it was Homo sapiens and not another hominid. That would be exciting in its own right, but until there’s more confirmation we should be careful not to describe these as facts or highly-probable.
    - moloch-hai 4y ago
      There seems no possibility of an upset to Cerutti. Bone fragments in the rock faces, greenstick fracturing, adjacent placement of stones and hip-joint ends. The only plausible complaint I have heard of is lack of stone-knife flakes, but the site is still being excavated. That it might have been H. e. is exciting. They did get around!
tiahura 4y ago
There were multiple out of Africa waves, and this seems like the simplest plausible explanation. Occam.

AlotOfReading 4y ago

The 16-17ka date is the divergence between Northern and southern native american groups, both related to the later (~13ka) clovis culture. Indigenous americans as a whole diverged from Eurasians sometime before 20ka. That initial population eventually split into multiple lineages (Unsampled Population A, Ancient Beringians, Clovis ancestors) that entered the Americas, although it's not clear what order those events occurred in. We know that there was also later admixture between Alaskan and Eurasian populations across the bering strait and groups like the paleoinuit likely originated (partially) on the siberian side of the straight, but the vast majority of indigenous ancestry across the Americas as a whole derives to the ancestors of the clovis complex. It's not clear how preclovis people relate genetically to those clovis ancestors in the absence of genetic data for them.

crazygringo 4y ago

Yes, multiple waves is suggested near the very end of the article, and that this is a focus of current data collection: > Another possibility ties together evidence of Population Y and potential archaeological evidence at sites like White Sands. Could there have been multiple migrations into the Americas, with one pre-LGM migration consisting of Population Y individuals (and perhaps Unsampled Population A or other groups we have yet to identify), and one post-LGM migration? This would reconcile the archaeological evidence of early traces of humans in the Americas (if they are indeed legitimate, which has yet to be demonstrated to everyone’s satisfaction) and the genetic data. > Archaeologists sceptical of White Sands’ early dates are dubious of the second scenario, and it is admittedly speculative. We need a great deal more data, both genomic and archaeological, to test it. But, as a field, we are actively engaged in collecting that data, even as I type these words.

moloch-hai 4y ago

The comet strike of 12,800 years ago neatly wiped out north American camels, horses, giant sloths, mammoths, mastodons, saber-tooth cats, dire wolves, the biggest bear and bison, cheetahs, and numerous other species, and neatly terminated all Clovis production. It would not be a stretch to guess it also wiped out most of the people making the Clovis points. People living in southeast Asia 70,000 years ago were certainly sailing out of sight of land, because they reached and colonized Australia. It beggars belief to suggest they did not also go to other places in equally easy reach, and then others from there. The article disgracefully trots out, once again, the "construction equipment" claim about the Cerutti mastodon site, despite its thorough refutation. The article further vindicates Graham Hancock's complaints of vicious mis-representation. His projections are certainly wrong in myriad details, but he is totally sincere in advancing them. He has predicted, correctly, embarrassingly many recent developments historians laughably insisted were impossible; I would not be surprised at more. When you feel you need to lie about your opponent to discredit him, it tells us more about you than about him. Genetic evidence, and notions of a more-or-less constant rate of accumulation of mutations, are on much shakier ground than the author suggests. That unreliability is unfortunate for people obliged to rely on it. We can still learn a great deal from it about the order of migrations, but not so much their dates relative to geological events.

EdwardDiego 4y ago
Comet strike?
- jcranmer 4y ago
  There's a theory that the Younger Dryas was caused by an impact of a bolide on a North American glacier, usually of one that fragmented considerably on entry.
  - moloch-hai 4y ago
    There was certainly a bolide strike roughly coincident with the beginning of the 1300-year Younger Dryas cold spell. Whether the strike caused the Younger Dryas cold spell is a matter of speculation. We can anyway be confident that the cold spell did not cause the bolide strike.

jcranmer 4y ago

There is I think a little bit of chronological confusion that I will try to clear up. My understanding of the consensus rough chronology is as follows: * Populations move into Beringia maybe 20-25kya. (My knowledge of this date is particularly hazy). * Populations start moving from Beringia into the Americas. This date is highly contested, but it's accepted that this occurred at least 15kya. * Clovis culture starts up around 13kya, ends around 11.5kya. * Younger Dryas starts up 12.8kya, ends around 11.5kya. So genetic evidence suggesting that peopling starts from around 17kya isn't inconsistent with mainstream dates for peopling of Americas, although it would mean being suspicious of sites much older than 17kya. > but the really interesting question from here then is who were they and what happened to them? My interpretation of the evidence... they became Clovis culture.

moloch-hai 4y ago
The lakebed footprints securely scotch that timeline, and Cerutti blasts it to smithereens. The most that could be left of it is that these late migrations somehow wholly supplanted earlier populations. Either the earlier pop. died out before the later crew arrived, or ... well, genocide is a demonstrated human behavior. It is hard to carry out continent-wide without microbial assistance, but they could have had that.
- acdha 4y ago
  It’s cool to be excited about this - who wouldn’t be? - but you’re using very definitive language for highly speculative. The article outlines a timeline which, as with the post you’re replying to, is compatible with the White Sands lake footprints. The Cerutti site _could_ completely upset that theory but it’s far from proven that it’s not a misunderstanding, or that it was Homo sapiens and not another hominid. That would be exciting in its own right, but until there’s more confirmation we should be careful not to describe these as facts or highly-probable.
  - moloch-hai 4y ago
    There seems no possibility of an upset to Cerutti. Bone fragments in the rock faces, greenstick fracturing, adjacent placement of stones and hip-joint ends. The only plausible complaint I have heard of is lack of stone-knife flakes, but the site is still being excavated. That it might have been H. e. is exciting. They did get around!

tiahura 4y ago

There were multiple out of Africa waves, and this seems like the simplest plausible explanation. Occam.