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Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

sciencemag.org

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Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#21

Post by bigbubba »

dragonwriter wrote: post #15
shard wrote: post #13

Earlier quoted context omitted.

1. ∀ Species ∈ Mammal, ∃ at least 1 member of Species that rapes 2. John does not rape 3. ∴ John is not the raping member of a Species of Mammals Pardon any misuse of symbols, it's been a while.

So, the first member of any mammal species must, ipso facto , be a rapist?

What would the 'first' of a species be, in an objective sense? As I understand it, speciation is a gradual process. Trying to pin down exactly where the change occurs is like trying to pin down precisely where a rainbow gradient shifts from green to yellow. You can pick a point and declare that to be the demarcation line, but discrete categorization in this way seems inherently arbitrary.

Even seeming straight forward metrics like "can they produce viable offspring" isn't so black and white, since between 'yes' and 'no' exists a continuum of 'maybe's. In very rare cases even horses and donkeys can have fertile offspring, e.g. mules that aren't mules (the typical infertility of mules has lead to the occasional use of the term to describe any infertile hybrid.)

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#22

Post by Groxx »

thaumasiotes wrote: post #9
chmod775 wrote: post #5

Earlier quoted context omitted.

This sentence doesn't make any sense: "H. sapiens doesn’t have the possibility of quickly grabbing a load of diversity by mating with another group". It would make sense if she specifically referred to Homo sapiens sapiens, but for Homo sapiens that "other group" would be of a different species and we thus we shouldn't be able to produce fertile offspring with them. Also Homo sapiens sapiens have plenty of genetic di…

> but for Homo sapiens that "other group" would be of a different species and we thus we shouldn't be able to produce fertile offspring with them. That's one definition of "species" (specifically, it's "the biological species concept"), but like all the other definitions, it doesn't work and does not correspond to most usage of the term. You can read modern genetic work discussing how homo sapiens interbred with homi…

It also wouldn't surprise me if "can reproduce with" isn't a transitive property (edit: actually, I'd be very surprised if it always is. genetic stuff is never that simple). So even if you try to collapse species into that strict definition, you'll still have edge cases that don't fit.

Categories are hard.

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#23

Post by bigbubba »

Groxx wrote: post #22
thaumasiotes wrote: post #9

Earlier quoted context omitted.

> but for Homo sapiens that "other group" would be of a different species and we thus we shouldn't be able to produce fertile offspring with them. That's one definition of "species" (specifically, it's "the biological species concept"), but like all the other definitions, it doesn't work and does not correspond to most usage of the term. You can read modern genetic work discussing how homo sapiens interbred with homi…

It also wouldn't surprise me if "can reproduce with" isn't a transitive property (edit: actually, I'd be very surprised if it always is . genetic stuff is never that simple). So even if you try to collapse species into that strict definition, you'll still have edge cases that don't fit. Categories are hard.

You're right, it isn't necessarily transitive. So called 'ring species' are cases where it isn't.

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#24

Post by scarmig »

bigbubba wrote: post #23
Groxx wrote: post #22

Earlier quoted context omitted.

It also wouldn't surprise me if "can reproduce with" isn't a transitive property (edit: actually, I'd be very surprised if it always is . genetic stuff is never that simple). So even if you try to collapse species into that strict definition, you'll still have edge cases that don't fit. Categories are hard.

You're right, it isn't necessarily transitive. So called 'ring species' are cases where it isn't.

You don't even have to go as exotic as ring species. Climb up the evolutionary tree through each of your ancestors to some slime creature a billion years ago, and then climb down to your pet dog. Each connected node in that step can interbreed, but you can't mate with Fido.

I guess it's kind of a temporal ring species.

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#25

Post by autokad »

dragonwriter wrote: post #16
holoduke wrote: post #14

Earlier quoted context omitted.

Covid is comparable to flu with a higher mortality rate. Don't make it bigger than it is. 99.95% of the people are doing perfectly fine. Genetics are thus pretty effective

> Covid is comparable to flu with a higher mortality rate. So, like 1918 pandemic flu?

the 1918 spanish flu death rate was around 20%. It was only in March 2020 after covid19 was mainstream news it got edited in Wikipedia to show 2% (not sure if that's changed by now), you can check the edit history. But in short, in 1918, there were coffin shortages, compared to the toilet paper shortages with covid19.

covid19 and the Spanish flu are not even in the same weight class, not even a little bit, whereas yes, like it or not, covid19 is most likely in the same weight class as the flu depending on your thresholds with the flu at .1% and CV19 around .5 to 1% (likely closer to .5%).

yes, there are some people with long term effects of cv19. that's also true of the flu. Many scientists think age related dementia is caused by repeated exposures to the flu/cold. flu/cold have also caused heart and organ damage to many, it just doesn't get reported on. 'oh, this person died of organ failure, wonder why'. It's already a proven fact that the flu has caused the onset of type 1 diabetes for example. There are also many reported cases of heart disease caused by the flu. the flu sucks.

people loose their sh*t when you talk about this. it doesn't minimize the effect of covid19, it just highlights the flu is something serious. for some reason, people are too immature to handle that. or maybe it goes against their worldview we should burn the world to the ground in order to stop covid19.

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#26

Post by phkahler »

mc32 wrote: post #10
jimktrains2 wrote: post #4

It's a running joke in Dr who, where as humanity spreads into the starts there eventually ceases to be any pure humans (and many other alien species) because humans will mate with anything. I think it's most interesting to think of how fluid what we mean by species really is. We've always known it was fluid, but I think many people never really consider that when thinking about ourselves.

I thought that would be dogs which seem to want to hump on anything...

You haven't met Chad?

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#27

Post by abathur »

adenozine wrote: post #2

Man, I've always actually kinda wondered about this. I know it's macabre, but I think about human migratory routines and when different groups clashed back when life was so primitive and brutish, they're must've been those tendencies to rape and sexually conquer the opposition. Surely that is reflected in the genetic ledger of time. What a crazy insight. Genetics is such an interesting field. It's bonkers there's jus…

Humans and proto-humans have presumably done most of the fundamental things we do for a very long time.

https://www.smithsonianmag.com/science-nature/colored-pigmen...

https://en.wikipedia.org/wiki/Earliest_findings_for_hominid_...

There was inevitably conflict, but I'm skeptical of the "tendencies to rape and sexually conquer the opposition" framing. AFAIK there isn't much evidence for large amounts of inter-group violence. A paper like https://onlinelibrary.wiley.com/doi/full/10.1002/ajpa.23751 lays out a contra case that the absence of evidence isn't evidence of absence--but I think it is a reason to be cautious about what we project back on those populations.

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#28

Post by Ygg2 »

jimktrains2 wrote: post #4

It's a running joke in Dr who, where as humanity spreads into the starts there eventually ceases to be any pure humans (and many other alien species) because humans will mate with anything. I think it's most interesting to think of how fluid what we mean by species really is. We've always known it was fluid, but I think many people never really consider that when thinking about ourselves.

Dr. Who is wrong. We could not mate with anything amongst the stars. Even if aliens exist they would be radically different. You might as well as bone your VCR.

The act of separation would create new species. Not our drive to bone.

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#29

Post by Ygg2 »

chmod775 wrote: post #5
dfischer wrote: post #3

Interesting in the limelight of pandemics in regards to the closing paragraph: > Today, H. sapiens doesn’t have the possibility of quickly grabbing a load of diversity by mating with another group: For perhaps the first time in our history, we’re the only humans on the planet. It’s another reason to miss our extinct cousins, says population geneticist Carina Schlebusch of Uppsala University. “To have such a large den…

This sentence doesn't make any sense: "H. sapiens doesn’t have the possibility of quickly grabbing a load of diversity by mating with another group". It would make sense if she specifically referred to Homo sapiens sapiens, but for Homo sapiens that "other group" would be of a different species and we thus we shouldn't be able to produce fertile offspring with them. Also Homo sapiens sapiens have plenty of genetic di…

You're overlooking the fact that even if easily breedable pool of foreign species existed along H. sapiens, given enough time they would either be purged or become common ancestors to everyone by now.

Since they were purged and exist as remnants in individuals' DNA.

Re: Mysterious ‘super-archaic’ populations had multiple trysts with human ancestors

#30

Post by rsynnott »

chmod775 wrote: post #5
dfischer wrote: post #3

Interesting in the limelight of pandemics in regards to the closing paragraph: > Today, H. sapiens doesn’t have the possibility of quickly grabbing a load of diversity by mating with another group: For perhaps the first time in our history, we’re the only humans on the planet. It’s another reason to miss our extinct cousins, says population geneticist Carina Schlebusch of Uppsala University. “To have such a large den…

This sentence doesn't make any sense: "H. sapiens doesn’t have the possibility of quickly grabbing a load of diversity by mating with another group". It would make sense if she specifically referred to Homo sapiens sapiens, but for Homo sapiens that "other group" would be of a different species and we thus we shouldn't be able to produce fertile offspring with them. Also Homo sapiens sapiens have plenty of genetic di…

> Also Homo sapiens sapiens have plenty of genetic diversity.

Humans aren’t particularly genetically diverse, given our dispersal, though as far as I know there’s some disagreement on _why_.

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