6 ms·

The notable thing is that there was never a land bridge to the Philippines, so the denisovans would have swum or most likely traveled by canoe to the Philippine

by ummonk 5y ago

The notable thing is that there was never a land bridge to the Philippines, so the denisovans would have swum or most likely traveled by canoe to the Philippines.

throwawaycities 5y ago
History provides plenty of examples of humans transporting other humans and other species across seas against their will.
- chronic2703 5y ago
  > History provides plenty of examples of humans transporting other humans and other species across seas against their will. And looking at history, it seems this accelerated the positive development and advancement of the human species.
- dmoy 5y ago
  Note that larger oceangoing ships were not invented until about 25,000+ years later. Transporting humans against their will is a non-sequitur when considering the mode of transit. It would be canoes, rafts, or swimming. Whether voluntarily or not.
  - newsclues 5y ago
    I’m pretty sure I tied up another kid and transported them to an island as a child at summer camp in the 90s. It’s possible.
  - throwawaycities 5y ago
    As I said there are plenty of examples in history of transporting humans against their will, and yes those historical examples include canoes and rafts. I think it’s much more probable there had to have been complex social relationships between these groups rather than the only possibility being that 1 species of prehumans developed single person boats used to migrate to these islands and then a second species of prehumans independently developed boats that also held a maximum of 1 person and used them to migrate to the same islands already inhabited by the 1 group, and then the 2 groups interbred per the article.
legutierr 5y ago
I would wager that the integration of the Denisovians with this community's other ancestors happened in mainland Asia, long before their decedents traveled to the Philippines.
- ummonk 5y ago
  You’re arguing for a founder effect explaining the higher Denisovan proportion on the island vis a vis other parts of southeast asia?
  - garbagetime 5y ago
    Are you implying that wouldn't make sense? Because it makes sense to me.
    - ummonk 5y ago
      That was my first thought when I had seen news of the paper, but the paper had some data to suggest the negritos split off from other sapiens before the denisovan introgression.
  - deleted 5y ago
    [deleted]
  - spoonjim 5y ago
    Makes sense. Denisovan descendants go to Philippines, the ones left behind get killed off by some other land-based group.
- kurthr 5y ago
  Yep, when you're looking at relatively low concentrations that are constantly falling (each generation) then looking at an island to find a higher concentration makes a lot of sense long after concentrations were actually high.
- gerdesj 5y ago
  "I would wager that the integration of the Denisovians with this community's other ancestors happened in mainland Asia, long before their decedents traveled to the Philippines." Cool idea. Where are you digging? Are you aware of just how convoluted and bloody complicated things get when you look at notions like species in the past? Denisovans do not really have a fixed point in the taxonomy (whatever that really means.) Their existence is inferred from a few teeth and bones - good evidence though. Well let's put it like this: we know far more about Mars than the Denisovans. You use terminology like "decedents traveled to the Philippines." I'll ignore speling but what you really mean is that some genes have been found, not fully formed descendants discovered. Unless you've got some eyewitness grade evidence, you cannot simply decide that someone clung to a log or paddled their canoe or sailed ... etc and lo the Philippines was won. That's simply silly and sounds like a US style "how the West was won" grade phantasy. I'll wager that we will gradually learn a bit more about a group of early humans that we call Denisovans and the link with the Philippines. We already have a genomic link - a group there: Ayta Magbukon has more in common than anyone else. As to how those genes got there is unlikely to be worked out directly.
StreamBright 5y ago
Or we miss crucial details about our history.
08-15 5y ago
It is far more notable that there is exactly one known Denisovan fossil, namely the distal phalanx the whole "Denisovan Genome" was sequenced from. One could argue that she was just another Neanderthal, but that didn't do the vanity of the authors of "Genetic history of an archaic hominin group from Denisova Cave in Siberia" [Reich2010] justice. Regarding the admixture, the analysis doesn't indicate the direction. If a Denisovan had offspring with an ancestor of present day Philippinos and the offspring stayed with the humans, that would create exactly the same D-statistics as if the child stayed with the Denisovans. I think the most believable scenario is that humans migrated through an area that was already inhabited by Neanderthals, some of them had fun with the locals, and the Denisovan is an offspring of such a family. That's much easier to believe than Denisovans, who somehow never left traces in the fossil record, living all over Asia and contributing genes to all present day Melanesians. [Reich2010] has a single sentence to rule out this scenario: the fossil is a tiny bit too old to be affected by the migrating modern humans. That relies on stratigraphic dating (C14 fails at around 50ka), and that relies on the assurance of the archaeologists that "most of the site was disturbed, but this fossil is from the undisturbed part!" Yeah, right. As you said, Denisovans, assuming there was ever more than one, and assuming they weren't just Neanderthals, probably swam to the Philippines. Isn't it amazing how much we can learn from a single pinky bone?
- bugzz 5y ago
  We have plenty of Neanderthal genetic sequences. So seeing even just one Denisovan sequence showing a large divergence from all the other Neanderthal sequences is enough to demonstrate a separate, distinct population.
  - 08-15 5y ago
    How much is large? The dendrogram is right here: https://www.eva.mpg.de/genetics/genome-projects/neandertal/ https://www.eva.mpg.de/genetics/genome-projects/neandertal/ The difference between the Denisovan and the Neanderthals is bigger than between San and French, but not by much. Keep in mind that the archaic genomes are noisy, and noise adds to their distance. At the time, the debate was whether Neanderthals and the Denisovan constitute different species or just different subspecies. (Taxonomy is fun. You get to name species you discover after yourselves. I'd love to discover a new species, but in a pinch, a subspecies will do.) You use the meaningless term "population". Whatever, let them be different populations. Now we have two populations, namely the "Denisovan" and the "Altai Neanderthal" living in the same cave, at roughly the same time.
deleted 5y ago
[deleted]
vatotemking 5y ago
Are you sure? Southeast Asia including the Philippines used to be part of Sundaland. Its even taught in the history books of the Philippines - that it was connected with present day Borneo. [https://en.wikipedia.org/wiki/Sundaland https://en.wikipedia.org/wiki/Sundaland]

by ummonk 5y ago

The notable thing is that there was never a land bridge to the Philippines, so the denisovans would have swum or most likely traveled by canoe to the Philippines.

throwawaycities 5y ago

History provides plenty of examples of humans transporting other humans and other species across seas against their will.

chronic2703 5y ago
> History provides plenty of examples of humans transporting other humans and other species across seas against their will. And looking at history, it seems this accelerated the positive development and advancement of the human species.
dmoy 5y ago
Note that larger oceangoing ships were not invented until about 25,000+ years later. Transporting humans against their will is a non-sequitur when considering the mode of transit. It would be canoes, rafts, or swimming. Whether voluntarily or not.
- newsclues 5y ago
  I’m pretty sure I tied up another kid and transported them to an island as a child at summer camp in the 90s. It’s possible.
- throwawaycities 5y ago
  As I said there are plenty of examples in history of transporting humans against their will, and yes those historical examples include canoes and rafts. I think it’s much more probable there had to have been complex social relationships between these groups rather than the only possibility being that 1 species of prehumans developed single person boats used to migrate to these islands and then a second species of prehumans independently developed boats that also held a maximum of 1 person and used them to migrate to the same islands already inhabited by the 1 group, and then the 2 groups interbred per the article.

legutierr 5y ago

I would wager that the integration of the Denisovians with this community's other ancestors happened in mainland Asia, long before their decedents traveled to the Philippines.

ummonk 5y ago
You’re arguing for a founder effect explaining the higher Denisovan proportion on the island vis a vis other parts of southeast asia?
- garbagetime 5y ago
  Are you implying that wouldn't make sense? Because it makes sense to me.
  - ummonk 5y ago
    That was my first thought when I had seen news of the paper, but the paper had some data to suggest the negritos split off from other sapiens before the denisovan introgression.
- deleted 5y ago
  [deleted]
- spoonjim 5y ago
  Makes sense. Denisovan descendants go to Philippines, the ones left behind get killed off by some other land-based group.
kurthr 5y ago
Yep, when you're looking at relatively low concentrations that are constantly falling (each generation) then looking at an island to find a higher concentration makes a lot of sense long after concentrations were actually high.
gerdesj 5y ago
"I would wager that the integration of the Denisovians with this community's other ancestors happened in mainland Asia, long before their decedents traveled to the Philippines." Cool idea. Where are you digging? Are you aware of just how convoluted and bloody complicated things get when you look at notions like species in the past? Denisovans do not really have a fixed point in the taxonomy (whatever that really means.) Their existence is inferred from a few teeth and bones - good evidence though. Well let's put it like this: we know far more about Mars than the Denisovans. You use terminology like "decedents traveled to the Philippines." I'll ignore speling but what you really mean is that some genes have been found, not fully formed descendants discovered. Unless you've got some eyewitness grade evidence, you cannot simply decide that someone clung to a log or paddled their canoe or sailed ... etc and lo the Philippines was won. That's simply silly and sounds like a US style "how the West was won" grade phantasy. I'll wager that we will gradually learn a bit more about a group of early humans that we call Denisovans and the link with the Philippines. We already have a genomic link - a group there: Ayta Magbukon has more in common than anyone else. As to how those genes got there is unlikely to be worked out directly.

StreamBright 5y ago

Or we miss crucial details about our history.

08-15 5y ago

It is far more notable that there is exactly one known Denisovan fossil, namely the distal phalanx the whole "Denisovan Genome" was sequenced from. One could argue that she was just another Neanderthal, but that didn't do the vanity of the authors of "Genetic history of an archaic hominin group from Denisova Cave in Siberia" [Reich2010] justice. Regarding the admixture, the analysis doesn't indicate the direction. If a Denisovan had offspring with an ancestor of present day Philippinos and the offspring stayed with the humans, that would create exactly the same D-statistics as if the child stayed with the Denisovans. I think the most believable scenario is that humans migrated through an area that was already inhabited by Neanderthals, some of them had fun with the locals, and the Denisovan is an offspring of such a family. That's much easier to believe than Denisovans, who somehow never left traces in the fossil record, living all over Asia and contributing genes to all present day Melanesians. [Reich2010] has a single sentence to rule out this scenario: the fossil is a tiny bit too old to be affected by the migrating modern humans. That relies on stratigraphic dating (C14 fails at around 50ka), and that relies on the assurance of the archaeologists that "most of the site was disturbed, but this fossil is from the undisturbed part!" Yeah, right. As you said, Denisovans, assuming there was ever more than one, and assuming they weren't just Neanderthals, probably swam to the Philippines. Isn't it amazing how much we can learn from a single pinky bone?

bugzz 5y ago
We have plenty of Neanderthal genetic sequences. So seeing even just one Denisovan sequence showing a large divergence from all the other Neanderthal sequences is enough to demonstrate a separate, distinct population.
- 08-15 5y ago
  How much is large? The dendrogram is right here: https://www.eva.mpg.de/genetics/genome-projects/neandertal/ https://www.eva.mpg.de/genetics/genome-projects/neandertal/ The difference between the Denisovan and the Neanderthals is bigger than between San and French, but not by much. Keep in mind that the archaic genomes are noisy, and noise adds to their distance. At the time, the debate was whether Neanderthals and the Denisovan constitute different species or just different subspecies. (Taxonomy is fun. You get to name species you discover after yourselves. I'd love to discover a new species, but in a pinch, a subspecies will do.) You use the meaningless term "population". Whatever, let them be different populations. Now we have two populations, namely the "Denisovan" and the "Altai Neanderthal" living in the same cave, at roughly the same time.

deleted 5y ago

[deleted]

vatotemking 5y ago

Are you sure? Southeast Asia including the Philippines used to be part of Sundaland. Its even taught in the history books of the Philippines - that it was connected with present day Borneo. [https://en.wikipedia.org/wiki/Sundaland https://en.wikipedia.org/wiki/Sundaland]