81–90 of 182 posts
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Probably less than 40k? Since it took a while for modern humans to leave Africa.
I don’t think the out-of-africa hypothesis is defensible in light of recent archeological findings, and, incidentally, DNA complexity analysis.
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Scientists are not lying. Reich is notable in his field and no-one is disputing his genetic research. What scientists are wary of is how any discussion in the field gets jumped on and twisted into ammunition to reinforce racist beliefs, whether the science actually supports this or not.
“What scientists are wary of is how any discussion in the field gets jumped on and twisted into ammunition to reinforce racist beliefs” Yet nothing ruined the reputation of the scientific establishment more in recent time than their tendency to change their behaviours and adapt their beliefs for political motives
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The definition of what constitutes a species is a human construct. Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other. So your question is hard to answer.
> Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other. Really? I thought the requirements for species classification were: (1) must be able to reproduce and (2) offspring must be fertile. Is it less objective than that?
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It's unfortunate that the URL happens to be buzzfeed, but there was an open letter to Reich by other academics about his terminology in the book you're quoting [0]. The short of it is that social categorizations we believe in like race intersect with genetics in a very complicated way. Reich is a world-class expert in genetics. He simply commits the same error as many other other experts in discounting the complexity…
> race intersect with genetics in a very complicated way Please explain the complications. Use scientific terms only.
Another major complexity is that some races are defined more by genealogic ancestry than by genetic ancestry or easily identifiable physical characteristics. For example, people are normally considered Jewish if they have a Jewish mother. This leads to many genetically disparate subpopulations being lumped together as a Jewish race.
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> Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other. Really? I thought the requirements for species classification were: (1) must be able to reproduce and (2) offspring must be fertile. Is it less objective than that?
There are a lot of subtleties. Ring species are a particularly fun one: you can have a population that live around some natural obstacle (like a large body of water) where individuals can breed successfully with individuals near to them but not with ones further way (like directly across the barrier), in a continuum of variation.
This is really interesting, thank you. I've never heard of "ring species" before.
From the article: We finally observed signals of selection for combinations of alleles that today are associated with three correlated behavioural traits: scores on intelligence tests (increasing 0.74±0.12), household income (increasing 1.12±0.12) and years of schooling (increasing 0.63±0.13). These signals are all highly polygenic, and we have to drop 449–1,056 loci for the signals to become non-significant(Extended…
Why? This article just focuses on changes in West Eurasia (probably because that's what they had data for), but the bulk of changes that resulted in behavioral modernity surely occurred in Africa - where the genetic variability for them to occur was and still is far greater than elsewhere - and plausibly similar changes occurred in other regions such as Central Eurasia, Southeast Eurasia etc. West Eurasia was a backwater.
Is there any species, other than humans, that is found all across the globe (i.e. geographically separated), and has not differentiated into subspecies? Wolves, elephants, tigers, bears, and foxes have all been categorized into multiple subspecies each, distinct but able to interbreed.
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>Do humans not fit the standards for being broken into multiple subspecies? No. Multiple human subspecies did once exist (examples being Neanderthals, Denisovans, Homo Erectus, and Homo Floresiensis) but only our species, Homo Sapiens, remains (with traces of Neanderthal DNA so there was some interbreeding.) However race is a cultural and social construct. Different human races are not different human subspecies. A P…
> the vast majority of genetic variation exists within populations This particular argument (I am not talking about anything else) always looked to me as "inkblot defense" (Cephalopods muddy water to defend themselves). Genome is discrete. A single nucleotide polymorphism can have far-reaching consequences. So it's a bit like arguing that this collection of pentagons is not statistically different from this collectio…
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The definition of what constitutes a species is a human construct. Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other. So your question is hard to answer.
> Two bird populations living in the same locale but divided by a mountain range therefore not naturally breeding with each other would classify as a different species, even if they could breed with each other. Really? I thought the requirements for species classification were: (1) must be able to reproduce and (2) offspring must be fertile. Is it less objective than that?
How many species are there? This is why the term "species" can never be entirely objective. I remember the eureka moment I had when I finally understood this (admittedly somewhat simple) point.
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Do humans not fit the standards for being broken into multiple subspecies? I assumed that they would but "the science community" is too scared of the implications when idiots learn about it. I look at a sumatran tiger and a Siberian tiger and I see a lot less variance than I see when I look at a pygmy, a Norwegian, an sentinel islander, and a han Chinese person
>Do humans not fit the standards for being broken into multiple subspecies? No. Multiple human subspecies did once exist (examples being Neanderthals, Denisovans, Homo Erectus, and Homo Floresiensis) but only our species, Homo Sapiens, remains (with traces of Neanderthal DNA so there was some interbreeding.) However race is a cultural and social construct. Different human races are not different human subspecies. A P…
But who cares about such divisions if we all can interbreed?