Deep genetic affinity between coastal Pacific and Amazonian natives | Hacker News Reader

Deep genetic affinity between coastal Pacific and Amazonian natives

pnas.org

88 pointsThevet30 comments

I dont want to pollute this thread, but want to briefly describe my time (mid 2000s) as an undergrad with half a double-major in US anthropology.

I was on several occasions warned-off from doing projects that pertained to this very subject and a couple others [examples: h. neanderthalensis relation to modern humans (at the time in the face of mtDNA), some other N. American immigration hypotheses (eg, that pleistocene peoples could make boats)].

Being told repeatedly that authoring research on a subject would ruin a future career eventually drove me out of academia, despite excelling in all other ways. Grad school was worse. It was not a great experience. I could go on at length to describe my perception of why this was/probably still is, but a short take is: the architecture of American social science legitimacy is so delicate that even counter thoughts from undergrads need to be put down.

Somewhat relieving to have all those subjects slowly come into light. Not bitter, but do have a longwinded eyeroll after all this time.

But yes, Pacific cultures visited the Americas pre-Euro contact. It is funny claim otherwise given even a pop-culture understanding of east Asian and Islander seafaring methods of the pre-European era.

Rrrff. End rant.

Not to dismiss your experiences with academic anthropology, but this paper isn't actually about any transoceanic seafaring cultures. It's about the population structure of some of the first peoples of the Americas and their ancestors, which predate polynesians by something like ten to twenty thousand years. I made the same mistake on my initial reading too.

No worries, though I did not mention Polynesians.

This is not the venue to parse out what Australasian means, but, at least genetically, we would be discussing a much older population.

It is by definition about seafaring people, however, as the only accepted migration path to the americas has been over the bering straights.

edit: oops. now i see where you are coming from. Mea culpa. see comment re Pleistocene boats. Apologies for my derp

not necessarily seafaring people; the migration was over land, possible due to the lowering of sea level during the Last Glacial Maximum

afaik, or can even imagine, there were no land routes across the Pacific at even glacial maximum.

If you know different, tell.

> I could go on at length to describe my perception of why this was/probably still is, but a short take is: the architecture of American social science legitimacy is so delicate that even counter thoughts from undergrads need to be put down.

I'd like to read the long take. Maybe write it down somewhere :)

put a contact in your profile

> some other N. American immigration hypotheses (eg, that pleistocene peoples could make boats)].

Why were they so opposed to this? You can't leave us hanging...

EDIT: ok and why is this at -1??

There was a debate back in the 80s/90s about how the "beringia standstill population" got into the Americas south of the ice walls. It became a bit of a pressing issue once Monte Verde was accepted as unambiguous evidence of the pre-clovis hypothesis. There were basically two main, competing theories to explain it:

1) the "ice-free corridor" / inland route, where people simply walked from Alaska to the continental US/Canada and then on to South America and

2) the pacific coastal route, where people migrated along the coast. There's a variant of this involving boats, but they're practically the same in that they post-date the first boats by a huge margin and it only changes the chronology a little bit.

The ice-free corridor was the primary hypothesis for a bit because it matched the behavior of the Siberian populations they were descended from better, but it was basically defunct by the mid 00s because the timelines on plausible ice-free corridors were too late to explain Monte Verde. Since then, PCR has been the dominant theory for pre-clovis migrations and it just took undergrad textbooks awhile to catch up. I wouldn't be surprised if even lower level classes like AP World were still teaching the inland hypothesis.

The problem with that, as I understand it, is that the archaeological evidence for a coastal migration out of Beringia just isn't there?

That's why studies of the PCR have focused on more southernly areas, in particular the PNW and the Channel islands. If you want lots of details and citations, I'd recommend perusing the 40th anniversary review paper: https://doi.org/10.1017/aaq.2019.80

The problem with that problem is that all the evidence would be 300 feet underwater.

Nicely summarized.

In South Africa, Australia, South America, New Zealand, the 'native' (ie. non-European) peoples are granted near-mythical status, on the basis that they arrived tens of thousands of years before Europeans.

But if this kind of genetic evidence indicates that there were actually waves of migration, conquest and assimilation, that non-European migration waves were relatively recent, and that Europeans are just the most recent one, then the status of Europeans as 'bad guys' and everyone else as 'good guys' falls flat.

It doesn’t make sense to generalize across those (incredibly different) regions and also your generalization is just wrong.

I was about to ask the same question about the hypothesis.

Offtopic: sometimes HN audience gives weird scores. Don't take it personally (but it's kind of part of the etiquette not to explicitly discuss the scoring since it's never directly related to the topic of the discussion).

I wonder if this is more of an issue with American academic institutions than it is in other parts of the world (anthropologists avoiding the boat hypothesis, that is)? I note that this article [1] (from Norway) explicitly makes the connection to Thor Hyerdahl's theory - which, as I understand from what you've written here (and from talking to others) is considered in the same category as the Bermuda Triangle and UFOs by American anthropologists.

[1] https://sciencenorway.no/archaeology-history-society-and-cul...

I think Heyerdahl's issue is that he approached it as South Americans travelling to Polynesia, instead of some of the most capable navigators the world has seen travelling to South America.

Some claim it was racism, but IIRC, he based it on prevailing winds and currents, which are west to east... except for during an ENSO (El Nino Southern Oscillation) event, which were poorly understood, or even widely known of, at the time of Kontiki.

And there's some evidence of correlation between Polynesian westward migration, and ENSO events.

I cant comment on Hyerdahl--I just don't know much. A related hole in simian evolutionary theory pertains to new vs old world monkeys, if you want a deep rabbit hole.

edit: the US, afaik, is different in that cultural anthro shares department with archaeology and human/primate genetics at the undergrad level. It's good in the sense that the culturals have to take a bit of science, bad in that politics invade all the subfields.

That was not a rant by any means; it was genuine, and refreshingly resonant to (i'm sure) many reading with similar learned skepticisms about graduate academia.

So the first people(s) to pop SAm and the first people(s) to pop NAm were of different origin and arrived via different methods?

That's what it seems like. Reading this article on the topic https://www.sciencemag.org/news/2021/03/earliest-south-ameri... and it says:

"One unanswered question is why the Y signal hasn’t turned up in any North or Central American Indigenous groups. One possibility, Hünemeier suggests, is that the Y signal–bearing migrants simply stuck to the coast and made it to South America without leaving any genetic legacy up north"

Ok. But how about "Or they arrived on the shores of South America by boat" ? I don't understand why that hypothesis seems to be avoided? It seems much more credible than "the people with that particular genetic legacy hugged the coast all the way down to So America and didn't mix with any other groups along the way."

They did leave a genetic legacy up north in ancient remains like Anzick-1 and ancient Channel island remains [1]. That legacy simply no longer exists among most remaining native populations in the US and Canada. Moreover, they're still clearly related to North American natives, it's just a more distant relationship. So it's not that North Americans and South/Central Americans descend from different ancestral populations, the population structure is just poorly understood.

[1] doi.org/10.1126/science.aar6851

I wouldn't go that far. We're talking wildly different timescales. Migration to the Americas over the Bering was < 16,000 years ago, while the golden age of Polynesian exploration was only about 1,000-2,000 years ago.

Is this new or just additional details on previous studies along the same lines?

https://www.nature.com/news/dna-study-links-indigenous-brazi...

https://www.nature.com/articles/s41586-020-2487-2

https://www.sciencenews.org/article/south-americans-may-have...

https://www.smithsonianmag.com/science-nature/native-america...

The paper has nothing to do with polynesian or colonial era contacts. It's about the genetics of the people whose descendants would go on to populate the Americas and what they say about the routes they took to get there (pacific coastal route or inland).

I'm a bit surprised to see it here, this is a pretty niche subject.

three of those links are about the same study suggesting pre-colonial movement west from the south american coast towards polynesia, and one is about analysis of ancient remains.

this study involves a large genetic survey of modern indigenous populations not only along the coast but also in the interior of the continent, that suggests ancient movement from polynesia to the south american continent.

Not knowing who these "Australasian" peoples are makes this very confusing.

In this case it really is just a genetic grouping. Refers to the understood native population of, roughly, Australia--there is some overlap nearby.

The subject of human migration as revealed by genetics is super interesting: really puts into perspective how small we are, story wise, and to my mind, lends a sense of gratitude to the almost unimaginable hardships and victories that got us to where we are now, typing words into this temporary format.

> Refers to the understood native population of, roughly, Australia

Does this mean aboriginal Australians, Papuan type people? I had not realized that they had also reached South America. I am fascinated by that population set as it seems to have a deep culture of exploration "walkabout", "dreamtime" concepts. It is a shame so little is known about their adventures and history.

Reply on news.ycombinator.com