
DNA reveals we are all genetic mutts - mjfl
https://news.harvard.edu/gazette/story/2019/02/harvard-geneticist-no-populations-dna-is-pure/
======
thaumasiotes
> A similar prehistory occurred in the Iberian Peninsula where a third
> population, also arrived from the Steppes, joined the hunter-gather and
> farmer groups. In this case, DNA research shows that the third population
> was exclusively male: While only 40 percent of the population about 6,000
> years ago comes from the Steppes, 100 percent of the Y chromosomes do.

This doesn't say what the author wants it to say. If 100% of the Y chromosomes
come from the intrusive population, that doesn't mean that the intrusive
population was entirely male. It means that 100% of indigenous males were
exterminated, so that (after the intrusion) the male population was entirely
intrusive. All the males being intruders is a very different concept from all
the intruders being male.

~~~
astazangasta
No, it doesn't mean that either (extermination of males). It just means that
only Steppe Y-chromosomes survived. This could be the result of extermination,
or it could be the result of stochastic drift, or selection, or any number of
other scenarios that result in the loss of some set of Y chromosomes.

~~~
thaumasiotes
Realistically, extermination of males is exactly what it means. It cannot be
stochastic drift; the pool of chromosomes dying out is too large. It can be
selection (it _is_ selection), but it can only be the kind of selection that
involves every native male failing to have children at all, because the Y
chromosome does not recombine.

~~~
astazangasta
First of all, given that we only have a limited sample of the Y-chromosome
space, I don't think we can conclude that no native Y-chromosomes actually
survived. That aside, it's easy to get selection for specific Y chromosomes
without extermination, for example if you have a ruling caste whose males are
favored (e.g. by primogeniture) or through preferential mating by lineage.
See: the prevalence of the (presumed) Chingisid chromosome here:
[https://doi.org/10.1086%2F367774](https://doi.org/10.1086%2F367774)

------
deogeo
> “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?

~~~
danans
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.

~~~
mirimir
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.

~~~
danans
> 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-...](https://www.haaretz.com/jewish/non-jews-increasingly-hit-by-jewish-
diseases-1.5319996)

> 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.

~~~
mirimir
> 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](http://www.jewishencyclopedia.com/articles/11977-pedigree)

[https://www.chabad.org/library/article_cdo/aid/4045946/jewis...](https://www.chabad.org/library/article_cdo/aid/4045946/jewish/Why-
Cant-a-Convert-Marry-a-Kohen.htm)

[https://tikvahfund.org/uncategorized/intermarriage-can-
anyth...](https://tikvahfund.org/uncategorized/intermarriage-can-anything-be-
done/)

[https://www.jewishvirtuallibrary.org/marriage-in-
judaism](https://www.jewishvirtuallibrary.org/marriage-in-judaism)

[http://www.cohen-
levi.org/jewish_genes_and_genealogy/the_dna...](http://www.cohen-
levi.org/jewish_genes_and_genealogy/the_dna_chain_of_tradition.htm)

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1288118/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1288118/)

~~~
danans
> 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.

~~~
mirimir
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.

------
mirimir
There's also this:

> Once upon a time, 4,000 to 8,000 years after humanity invented agriculture,
> something very strange happened to human reproduction. Across the globe, for
> every 17 women who were reproducing, passing on genes that are still around
> today—only one man did the same.

So it seems like this was a common pattern.

[https://psmag.com/environment/17-to-1-reproductive-
success](https://psmag.com/environment/17-to-1-reproductive-success)

[https://genome.cshlp.org/content/early/2015/03/13/gr.186684....](https://genome.cshlp.org/content/early/2015/03/13/gr.186684.114.abstract)

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

This is such a shockingly ignorant statement that I wonder what Harvard is
teaching these days.

~~~
telotortium
Look up David Reich. The actual finding is that many Jātis show genetic
evidence that interbreeding with other Jātis has been negligible over the past
2000 years. It's not necessarily a statement of the social relations between
the Jātis, let alone the varnas.

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

“Colonial rule” means British rule presumably. I always assumed the caste
system long pre-dated it, considering how entrenched it seems to be.

~~~
danans
The British exploited it, and under them aspects of it became more rigid, but
it long predates them.

~~~
thaumasiotes
The data shows there was less than one inter-caste marriage per caste pair per
generation for the last few thousand years. What was left to become "more
rigid" than that under the British?

~~~
danans
For one thing, there is often a subcaste structure within each local caste
itself. The subcastes of a caste who received British patronage, i.e. jobs in
the colonial administration, would preferably marry only among themselves.

Of course, this was about preservation of wealth and power, and not so
different from similar marriage practices among wealthy classes in England (as
depicted in Downton Abbey)

The British didn't invent the sub-castes, but they effectively exploited them.

------
reader5000
More in depth article from Reich:
[https://www.nytimes.com/2018/03/23/opinion/sunday/genetics-r...](https://www.nytimes.com/2018/03/23/opinion/sunday/genetics-
race.html).

~~~
drilldrive
>What makes Dr. Watson’s and Mr. Wade’s statements so insidious is that they
start with the accurate observation that many academics are implausibly
denying the possibility of average genetic differences among human
populations, and then end with a claim — backed by no evidence — that they
know what those differences are and that they correspond to racist
stereotypes.

Perhaps there is no hard evidence because nobody is willing to risk their
lively-hood over researching such claims. Just look at what they did to Dr.
Watson. Heck, a few paragraphs above Reich was talking about African-Americans
being genetically predisposed to prostate cancer as if it was a highly
controversial topic.

~~~
smrtinsert
Well, the problem is we probably can't find anyone to sponsor to study to
determine if once and for all, whites are prone to psychosis and mass murder
via guns.

~~~
drilldrive
Now that is quite the switch of topic. The only known research of race
differences in psychopathy is of Richard Lynn's 2002 studies on the topic. In
this, Lynn does point to whites being more prone to psychosis than on average.
I do know of some controversy of Richard Lynn's work, and here is a response
paper to such:
[https://web.archive.org/web/20130108233748/http://riskreduct...](https://web.archive.org/web/20130108233748/http://riskreduction.soceco.uci.edu/wp-
content/uploads/2011/01/Psychopathic-personality-and-racial-ethnic-
differences-reconsidered.pdf)

Regarding school shootings in particular, my personal guess is that such sour
actions on the average are merely a symptom of a hole in America's conscious,
in that these semi-affluent white boys have lost meaning in life, and do not
care if the actions they commit are grave. Of particular note is you do not
see boys of abject poverty commit these actions, as they are more focused on
not starving (and thus have something obviously meaningful to their life to
prioritize).

~~~
scythe
_Psychopathy_ , i.e. antisocial personality disorder, and _psychosis_ , the
state of experiencing delusions and/or hallucinations, are two very different
things.

~~~
drilldrive
Oh yes, my apologies. Although in my defense I would connect psychopathy with
school shootings rather than psychosis. And by a brief search it seems that in
America whites on average are diagnosed with psychosis much less often than
blacks and hispanics:
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4274585/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4274585/)

------
RcouF1uZ4gsC
> The Steppe migration resulted in a 90 percent replacement of the population.

>While only 40 percent of the population about 6,000 years ago comes from the
Steppes, 100 percent of the Y chromosomes do.

From reading this article it seems another way that this could be phrased, is
that we are all the descendants of perpetrators of genocide.

~~~
Noumenon72
Don't forget the rape!

100% of your Ys coming from one place is the opposite of "mutt", too. But the
only way you can get to do race science is by coming to the conclusion
"There's no such thing as race" first, and making the details sound boring
enough that nobody asks.

~~~
dqpb
The concept of race has always sounded like total bullshit to me. Do you have
a definition that makes any sense?

~~~
haihaibye
Sequence the world and run them through a clustering algorithm, picking how
many clusters you get:

2 clusters: African and non-African

5 clusters: African, European, Asian, PNG/Australian Aboriginal, Native
Americans

All the way to:

1 billion clusters: Individual families

When most people think of race they are talking about the number of groups
that make clusters of major continents, where there wasn't much gene flow
until 1492.

Google PCA ancestry (PC term for race) eg gnomAD:

[https://encrypted-
tbn0.gstatic.com/images?q=tbn%3AANd9GcSZ-l...](https://encrypted-
tbn0.gstatic.com/images?q=tbn%3AANd9GcSZ-lBFuHuVO2g446dI21P0F8oqcmLYAGZAXy-
Yg9uJ5ULt2Pxd)

Self reported race matches genetically determined race at rates in the high
90s.

A way to think about it without clustering etc:

People separated (usually by geography) long enough that they bred mostly
amongst themselves, and developed characteristics different than other groups.

Yes, you can walk from Amsterdam to Beijing and see a gradient of people the
whole way - but that doesn't mean you can't tell the difference between a
Chinese person and a Dutchman.

------
ng12
I wonder how many of these genetic migrations were peaceful.

~~~
mjfl
probably very few, if the old testament or the huge proportion of ancient
skeletons that died violent deaths serve as any guide. which is why I think
this story by Reich is _very_ tone deaf. It's hard to see how a 90% population
replacement promotes feelings of unity and hand-holding.

One imagines a superposition of a video feed of the invasion of the steppe-
people on horseback, stampeding the native defenses, cutting the male
children's throats and raping the women, with a video a David Reich being like
"we're all a little mixed".

~~~
duality
Tone deaf indeed. It seems common for people not to ascribe a full measure of
humanity to humans from the (distant enough) past. Thought exercise: are there
any large-scale population replacements happening today, and how do people
feel about that? Surely not a kumbaya feeling I'd bet.

~~~
perilunar
In the recent past: the Americas, Australia, New Zealand, Fiji?, etc.

Current: Tibet, West Papua, Rwanda?, Northern Europe perhaps?

~~~
deogeo
Add Xinjiang to the list of current ones - from
[https://www.nytimes.com/2019/03/02/world/asia/china-
muslim-d...](https://www.nytimes.com/2019/03/02/world/asia/china-muslim-
detention-uighur-kazakh.html), flagged off the HN front page: "Decades of
migration by Han, China’s dominant ethnic group, have transformed Xinjiang,
fueling Uighur anxieties. Uighurs, once the majority, are 46 percent of the
region’s 22 people million people, Han are 40 percent and Kazakhs 7 percent,
according to government estimates."

------
quoyz
David Reich you say.

------
vricius
of course we are all mutts, we all evolved from bacteria. the question is the
relative purity. "is the race pure from this period to this period" is what
people mean when they mention purity. When a jew chooses a mate, they are only
concerned if their mate has pure jewish ancestry from the last 2000 years.

~~~
pryce
That doesn't equate to "relative purity" at all. The number of ancestors
someone has 66 generations in the past (approx 2000 years) is enormous. We can
get around this by making value judgements that say "only the direct
matrilineal line ancestors count" or "only the direct patrilineal line
ancestors count", but ideas like that are absolutely human value judgements
made as a reaction to the overwhelming complexity above, and have no basis in
biology. These value or worth of those judgements are also artificially
enforced and were not robustly adhered to historically. We are indeed all
mutts, and every credible analysis for the last century has shown "race
purity" is an abstraction that is absurd to the point of lunacy.

~~~
defen
> We are indeed all mutts

I get why Reich says things like this, but you have to ask what it would mean
_not_ to be a "mutt". Is that even physically possible? If not, why do we need
DNA testing of ancient skeletons to prove this?

