Razib Khan One-stop-shopping for all of my content

July 9, 2020

Cancel Muhammad?

Filed under: Islam — Razib Khan @ 11:30 pm

The person above is a professor at a “Research 1” university. He clearly does not know that Cato was a Plebian. That he held the position of Tribune of the Plebs, which existed to allow for Plebian political rights within the Roman system when Patricians were dominant.

As it is, decades before Cato the Younger’s career, the Plebian nobility had obtained nearly all the privileges of the Patricians. The main exceptions were particular religious priesthoods. In some ways, this left the Plebian nobility with more power than Patricians, because they also were able to become Tribunes of the Plebs, an office banned to Patricians (The Patrician Publius Clodius Pulcher had himself adopted by a Plebian so he could obtain this office).

In any case, this broadside against the Cato Institute because it is named after a “bad bad man” has prompted me to write about something that has been on my mind: two billion human beings see in Muhammad an exemplar, but the Muhammad himself is eminently cancelable.

There are two primary issues I want to bring up:

1) Muhammad owned slaves. Yes, he was kind to them, but the Prophet of God owned slaves.

2) The consummation of his marriage to Aisha when she was nine years old seems highly likely if the historical Muhammad existed.

As most of you know, I have been reading Muhammad and the Empires of Faith. The author’s analysis comes to the conclusion that the tradition that Muhammad married Aisha when she was six and consummated the marriage when she was nine is credible. Aside from the traditional textual analysis, it seems that this practice was actually known in Arabia at the time. In other words, it was socially normative in the milieu in which Muhammad existed. Jonathan Brown, a noted historian, and conservative Muslim, also accepts the validity of this tradition of Muhammad and Aisha’s relationship.

Where does that leave us? I am not a Muslim. I am an atheist. I think someone like Muhammad did exist, but my confidence is modest. Additionally, I’m still not sure that this tradition is accurate, and reflects reality. But, the joint probability is probably in the range of 50% in my estimation.

But, I was raised a Muslim, and I remember what we were taught about the Prophet, Peace Be Upon Him. He was understood to be an exemplar of humanity. There are various reasons to be skeptical of this…he was, after all, a man of the sword as well as religion. But the fact that may have consummated his marriage with Aisha at the age of nine leaves me appalled in a very deep way.

At the time I was reading Muhammad and the Empires of Faith this very popular tweet about Joseph Smith was brought to my attention:

There are a few details that need to be fleshed out. Smith had sex with teens. He was technically an ephebophile. Second, Mormonism was not notably racist during the period of Smith’s life. Much of the racism came to the fore under Brigham Young and his successors. Also, Mormon racism was general but particular against people of African ancestry (other nonwhite people were seen somewhat differently).

I think Joseph Smith is much more likely to be “canceled” than Muhammad. First, Smith lived in the 19th century. That’s much closer to us. Second, the Church of Latter-Day Saints is perceived to be white, even though most of the world’s LDS are now nonwhite. Finally, the LDS and affiliated movements have active memberships in the range of tens of millions. There are two billion Muslims.

The question of Muhammad is only interesting because it illustrates the calculus of cancellation. We know that it is unlikely there will be a Twitter hashtag #cancelMuhammad outlining his ownership of slaves, his genocide against defeated foes, in particular Jews, and, his pedophilia. In fact, I am very careful not to say stridently anti-Muslim things on Twitter, because past experience indicates that Twitter is very censorious of this. A #cancelMuhammad hashtag would probably get you canceled from the platform!

As Ezra Klein has said, questions of speech and freedom are about power. The Ummah has power, and it shall never err in consensus.

Always mind the power-level when you target someone.

Let’s talk about sexual selection and Charles Darwin

Filed under: Human Evolution — Razib Khan @ 5:36 pm

Charles Darwin famously posited the origin of species through adaptation driven by natural selection. The theory of evolution as we understand it. But another of Darwin’s major ideas was that sexual selection was very important in driving diversity within species. More specifically Darwin thought that female choosiness was critical and explained why in species such as birds the males were so much more “showy.”

Sexual selection is a huge field of study, and it’s hard to deny that it is a real thing. But, there has long been an argument about the efficacy of sexual selection within humans. Depending on how you define it, it does not seem that humans are particularly sexually dimorphic compared to common chimpanzees and gorillas, for example. This goes back to whether we are polygynous or monogamous. Because of high reproductive variation for males in polygyny sexual selection can drive changes really fast (e.g., one super-fit male can produce huge numbers of offspring). The situation in monogamy is more difficult since there is less reproductive variance.

A new preprint seems to suggest that selection is happening on males, even today, due to deleterious genes. Sex-biased reduction in reproductive success drives selective constraint on human genes:

Genome-wide sequencing of human populations has revealed substantial variation among genes in the intensity of purifying selection acting on damaging genetic variants. While genes under the strongest selective constraint are highly enriched for Mendelian disorders, most of these genes are not associated with disease and therefore the nature of the selection acting on them is not known. Here we show that genetic variants that damage these genes reduce reproductive success substantially in males but much less so in females. We present evidence that this reduction is mediated by cognitive and behavioural traits, which renders male carriers of such variants less likely to find mating partners. Our findings represent strong genetic evidence that Darwin’s theory of sexual selection is shaping the gene pool of contemporary human populations. Furthermore, our results suggest that sexual selection can account for about a quarter of all purifying selection acting on human genes.

The figure to the right gets at the major finding. More mutations mean a far more rapid drop in fitness for males than females. Why? The major reason seems to be that males can’t find a partner. If they can find a partner, the effect is much weaker. Basically, this is detecting an increase in childlessness.

A plausible explanation is that it impacts fertility, but the above indicates that that is not the case. And, the deleterious mutations aren’t enriched in the testes, nor does pruning out loci with known reproductive effects remove the impact. The authors also looked at intelligence. Those with mutations were not as intelligent, but that can’t explain most of the effect (and obviously it didn’t have much of an impact on women). The same with known conditions such as schizophrenia. Rather, what’s going on is that people are picking up on overall “genetic quality.”

There are major limitations of course. This is in British people. And, the samples from the Biobank tend to be somewhat healthier than average. There is a lot more work to be done with a lot more samples. But this is an awesome result in that it synthesizes the power and methods of modern genomics with a classical evolutionary hypothesis about the shape of human variation.

The main question I have regarding sexual selection then is what will the results in other societies be? As per Joe Henrich’s recent book, The WEIRDEST People in the World, the British have been in enforced monogamy for 1,000 years. Purifying selection could be much stronger in some non-WEIRD societies (and in inbred Arab cultures cousin-marriage would also ‘expose’ recessive alleles faster). That might mean there aren’t as many deleterious alleles. Or, it could be the effect is much stronger in those who have no children (males).

This is just the beginning. Perhaps it’s time to reread Geoffrey Miller’s The Mating Mind?

Native American admixture into Polynesia!

Filed under: Uncategorized — Insitome: Your guide to the story of you @ 2:02 pm

Razib talks to Alex Ioannidis on the new paper which he is a first author of which argues that there is pre-Columbian Native American ancestry in Eastern Polynesia. Did the Polynesians bring them back from the mainland? Or did they voyage themselves?


July 8, 2020

Thor Herydhal was right!

Filed under: Historical Genetics — Razib Khan @ 10:52 am

Native American gene flow into Polynesia predating Easter Island settlement:

The possibility of voyaging contact between prehistoric Polynesian and Native American populations has long intrigued researchers. Proponents have pointed to the existence of New World crops, such as the sweet potato and bottle gourd, in the Polynesian archaeological record, but nowhere else outside the pre-Columbian Americas…while critics have argued that these botanical dispersals need not have been human mediated…The Norwegian explorer Thor Heyerdahl controversially suggested that prehistoric South American populations had an important role in the settlement of east Polynesia and particularly of Easter Island (Rapa Nui)2. Several limited molecular genetic studies have reached opposing conclusions, and the possibility continues to be as hotly contested today as it was when first suggested…Here we analyse genome-wide variation in individuals from islands across Polynesia for signs of Native American admixture, analysing…individuals from 17 island populations and 15 Pacific coast Native American groups. We find conclusive evidence for prehistoric contact of Polynesian individuals with Native American individuals (around AD 1200) contemporaneous with the settlement of remote Oceania…Our analyses suggest strongly that a single contact event occurred in eastern Polynesia, before the settlement of Rapa Nui, between Polynesian individuals and a Native American group most closely related to the indigenous inhabitants of present-day Colombia.

I already recorded a podcast on The Insight with the first author that should post tonight. So I’m not going to put a long post, just subscribe to The Insight and listen to what the first author has to say. The major finding using high density SNP chips and local ancestry deconvolution seems to be that a group of people from mainland South America, probably coastal Columbia, was admixed into the population of the Marquesas. It is from the Marquesas that this genetic ancestry propagated across the eastern fringe of Oceania, including Easter Island.

July 7, 2020

The Jat Gene!

Filed under: Genetics — Razib Khan @ 4:15 pm

About 10 years ago there was a defunct blog called the “Jat Gene.” Standard stuff. Nothing super amazing discovered, but the Jats do seem on one end of the pole. I happen to have half a dozen Jats which cluster together. You can see where they are on the PCA plots above.

– no surprise that the Jat are on the ANI end of the ANI-ASI cline

– Please note that Jat and Ror and other such groups are distinct from Pathans and especially Baloch in that the latter groups seem to have more and later gene flow/contact from West Asian groups. Perhaps this is the Islamic period? Or perhaps this is just contact due to proximity. The Baloch and Brahui in particular are distinct because they have very little AASI. The Pathan are arguably an Iranian group with South Asian inflection, but the Baloch are just plain West Asian.

– You can see at the admixture plot below. The Jat are less (marginally) European-like than the Ror, but the Treemix indicates the Ror may actually be a mix of a very European-like group with native Indian (ANI-ASI mix). The Jat are probably the same but I don’t have the samples.


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