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Re:DNA reveals we are all genetic mutts by deogeo on Sunday March 03, 2019 @08:59PM (#19298232)
> “No population is, or ever could be, pure,”

Why this obsession with 'purity'? Isn't it obvious that, despite none being pure, some populations are more closely related?

Re:DNA reveals we are all genetic mutts by thaumasiotes on Sunday March 03, 2019 @10:24PM (#19298544)
> Isn't it obvious that, despite none being pure, some populations are more closely related?

It is obvious, and the same data shows that groups can be very pure indeed. From this very article:

> Genetics also show that India’s caste system, previously thought to have developed under colonial rule, was in place thousands of years earlier.

First, "previously thought to have developed under colonial rule" is just false. The ancient Greeks wrote about India's caste system, thousands of years ago.

Second, what the data shows is not a record of social structure. It shows that modern Indian castes have practiced endogamy -- mating within the group, with negligible inflow from other groups -- for thousands of years.

Most people would be happy to describe this state of affairs as "pure" ancestry.

Re:DNA reveals we are all genetic mutts by danans on Sunday March 03, 2019 @10:51PM (#19298631)
> First, "previously thought to have developed under colonial rule" is just false. The ancient Greeks wrote about India's caste system, thousands of years ago.

Correct, the article is flat wrong on this. Indian sources that even predate the Greeks also speak in detail about the societal arrangement.

> Second, what the data shows is not a record of social structure. It shows that modern Indian castes have practiced endogamy -- mating within the group, with negligible inflow from other groups

Yes, but they are still sampled, albeit in varying proportions, from the same source populations, referred to in the literature as ASI and ANI, which are themselves composite groups.

Re:DNA reveals we are all genetic mutts by thaumasiotes on Sunday March 03, 2019 @10:53PM (#19298638)
> Yes, but they are still sampled, albeit in varying proportions, from the same source populations, referred to in the literature as ASI and ANI.

Sure, but that was several thousand years ago. Again, most people are perfectly happy to describe unmixed ancestry for the last 2400 years as being "pure", and the castes go back farther than that.

Re:DNA reveals we are all genetic mutts by danans on Sunday March 03, 2019 @11:40PM (#19298824)
> Again, most people are perfectly happy to describe unmixed ancestry for the last 2400 years as being "pure", and the castes go back farther than that.

Just because "most people" are willing to draw that line at 2400 years doesn't make it a valid argument.

At most you could say that there is genetic evidence to support the hypothesis that the castes have practiced endogamy for a long time, evidenced by their characteristic genetic admixtures from their shared source populations, and that the caste hierarchy is roughly correlated with ANI admixture rate. That doesn't equate to the word "pure" at all.

People are willing to make all sorts of claims about their and others' identities to suit their personal agendas, and it's their right to do so, but they aren't doing science.

What about the many millennia that elapsed between the last major shared human population bottleneck and 2400 years ago?

Re:DNA reveals we are all genetic mutts by sterlind on Monday March 04, 2019 @02:45AM (#19299509)
This was a fascinating comment thread to follow. I've been looking for information on the endogamous groups of India, the early written history of the caste system and the genetics of these groups. Do you have any pointers?
Re:DNA reveals we are all genetic mutts by danans on Monday March 04, 2019 @11:27AM (#19302429)
The earliest known literary mention (not written - ancient Indians recorded and passed on their literature orally) of the caste system is the Purusha Sukta hymn from the Rigveda (late 2nd millennium BCE):

https://en.m.wikipedia.org/wiki/Purusha_Sukta

It's interpretation is varied and controversial to say the least.

But one shouldn't confuse the theoretical model presented in the liturgical texts (referred to with the term "varna", meaning "color" or "tone") with the concrete manifestation of traditional endogamous divisions in society (referred to with the term "jati", meaning "station of birth').

The ground reality is more oriented around the complexities of class, tribe, language and occupation, and even physical phenotype, which were then rationalized through the theoretical 4-fold system of caste.

There are parts of India (the southern and eastern parts) where the actual social structure doesn't map as cleanly to the 4-fold system, except among the higher castes. However endogamy and strong caste hierarchy is still just as common in these regions.

In terms of population genetics of South Asia specifically, here is a good place to start:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2702070/#__sec2...

Re:DNA reveals we are all genetic mutts by mjfl on Sunday March 03, 2019 @09:15PM (#19298295)
you get extra points if you can dress your scientific story as "speaking out against racism".
Re:DNA reveals we are all genetic mutts by vricius on Sunday March 03, 2019 @09:59PM (#19298462)
not sure why you were downvoted, this is exactly why they mentioned purity.
Re:DNA reveals we are all genetic mutts by known on Sunday March 03, 2019 @11:46PM (#19298843)
Re:DNA reveals we are all genetic mutts by danans on Sunday March 03, 2019 @10:06PM (#19298486)
It's a rebuke of the false trope of the purity of racial ancestry which has persisted in many human societies for centuries, occasionally manifesting in the form of events like the Holocaust.

Because that trope has sadly persisted to this day in some quarters, it's falsehood needs to be continually exposed, especially by sciences such as biological anthropology, which were once used to promulgate it.

Re:DNA reveals we are all genetic mutts by mirimir on Sunday March 03, 2019 @10:15PM (#19298513)
Actually, it's my impression that some Jewish groups have done a pretty good job at maintaining racial purity. In some cases, leading to ~frequent homozygousity for some nasty recessive mutations.

I don't know the specifics, but I've read that only certified Jews can officially marry in Israel. And the standards are so high that many "Jewish" immigrants don't qualify.

Now that we have DNA testing, I wonder if that will become the standard.

Re:DNA reveals we are all genetic mutts by danans on Sunday March 03, 2019 @10:40PM (#19298598)
> Actually, it's my impression that some Jewish groups have done a pretty good job at maintaining racial purity.

Because certain very specific subgroups have done this doesn't mean that they are "pure". These in-marrying groups are always descended from mixed populations in the first place, populations that predate the identity badges we ascribe to them today.

Tay Sachs, among the genetic diseases you alluded to, is also present in non Jewish populations, but at a lower rate:

https://www.haaretz.com/jewish/non-jews-increasingly-hit-by-...

> I don't know the specifics, but I've read that only certified Jews can officially marry in Israel. > And the standards are so high that many "Jewish" immigrants don't qualify.

People can convert to Judaism, and even be born into Judaism with one Jewish parent. This is very common among populations outside of Israel.

Large subgroups in Judaism, sephardi, baghdadi, etc, are genetically quite diverse in origin, and are significantly represented among the Israeli population.

Re:DNA reveals we are all genetic mutts by mirimir on Sunday March 03, 2019 @10:53PM (#19298639)
> People can convert to Judaism, and even be born into Judaism with one Jewish parent. This is very common among populations outside of Israel.

Yes, but to strict orthodox, they're not really "Jewish".

At one point, I researched rabbinical criteria for determining pedigree and classifying degree of Jewishness. Who can marry who, and how any children are classified. It's mind-boggling. If I have some time while this thread is hot, I'll post some sources.

Edit: Here are some sources. Please note that they're Jewish sources. Not anti-Jewish sources.

http://www.jewishencyclopedia.com/articles/11977-pedigree

https://www.chabad.org/library/article_cdo/aid/4045946/jewis...

https://tikvahfund.org/uncategorized/intermarriage-can-anyth...

https://www.jewishvirtuallibrary.org/marriage-in-judaism

http://www.cohen-levi.org/jewish_genes_and_genealogy/the_dna...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1288118/

Re:DNA reveals we are all genetic mutts by danans on Sunday March 03, 2019 @11:11PM (#19298706)
> Yes, but to strict orthodox, they're not really "Jewish".

Unless you are seeking to identify as "strict orthodox", why would it matter?

The majority of Jewish groups are welcoming to people from the outside, if they achieve the required objectives in terms of religious and cultural fluency.

Re:DNA reveals we are all genetic mutts by mirimir on Sunday March 03, 2019 @11:17PM (#19298730)
I don't really care, now.

But strict orthodox rules do apply in Israel. And that's not so insignificant. It's one reason why I'm in the US and not in Israel.

Re:DNA reveals we are all genetic mutts by ng12 on Sunday March 03, 2019 @10:26PM (#19298552)
I don't think it's a rebuke at all. The other side of the coin is to make sure you're the steppe tribes, not the hunter-gatherers. People who care about such things don't really care about purity, they care about winners and losers.
Re:DNA reveals we are all genetic mutts by danans on Sunday March 03, 2019 @11:22PM (#19298756)
> The other side of the coin is to make sure you're the steppe tribes, not the hunter-gatherers.

This doesn't follow from the researcher's statement at all. Just because the mechanism by which diversity happened thousands of years ago was often terrible doesn't mean we need to project that upon today, when we have much better mechanisms for genetic diversity, like immigration.

We, as a human society, have improved just a bit.

Re:DNA reveals we are all genetic mutts by ng12 on Monday March 04, 2019 @12:16AM (#19298970)
> We, as a human society, have improved just a bit.

I think it's debatable. The tribes are much bigger but really little has changed.

Re:DNA reveals we are all genetic mutts by danans on Tuesday March 05, 2019 @11:33AM (#19311685)
It's fascinating that my comment above rebuking racial purity theories is so controversial (evidenced by the oscillating down and up votes for a full day), yet there are no follow up comments supporting racial purity theory in general, just a discussion about the relative genetic isolation of one group?

It's surprising that rebuking racial purity as a concept would be so controversial today on a forum like this.