nhaliday + male-variability + pop-structure   9

Y-chromosome crash | West Hunter
there probably wasn't vast reproductive inequality ("17 to 1! woah") in the Bronze Age, and there wouldn't have to be to explain observed genetic patterns

https://westhunt.wordpress.com/2014/06/26/kings-of-the-stone-age/
https://westhunt.wordpress.com/2014/08/30/we-three-kings/
https://westhunt.wordpress.com/2014/09/07/the-genghis-khan-effect/

comment on TFR gradients in Malthusian conditions: https://westhunt.wordpress.com/2015/03/21/y-chromosome-crash/#comment-67790
“By contrast, the average number of surviving children for the majority of men was probably somewhere between zero and one – despite that they were having sex and babies.”

Fuck me, that’s obviously ridiculous. In real life, take a peasant village in England: if your model were correct, you’d have surname turnover every couple of generations. But that didn’t happen.

Here’s a model that’s at least in the ballpark: there was some class differential in fitness. The poorest, landless laborers, had a TFR below replacement, but not by a tremendous amount: 1.6? Most peasants were close to break-even, upper farmers did better than break-even, Other groups were mostly too small in number or too urban (population sinks) to matter. Overall TFR was of course break-even over the moderately long haul, in a sloppy way, with occasional epidemics and crop failures.
west-hunter  sapiens  antiquity  regularizer  speculation  gavisti  explanation  thinking  🌞  sex  gender  male-variability  winner-take-all  inequality  pop-structure  science-anxiety  scitariat  nietzschean  sexuality  gender-diff  null-result  deep-materialism  EEA  history  multi  aDNA  archaeology  conquest-empire  china  asia  genetics  genomics  poast  fertility  medieval  britain  demographics  malthus  class  correlation  blowhards  traces 
november 2016 by nhaliday
PLOS Genetics: Natural Selection Reduced Diversity on Human Y Chromosomes
The human Y chromosome exhibits surprisingly low levels of genetic diversity. This could result from neutral processes if the effective population size of males is reduced relative to females due to a higher variance in the number of offspring from males than from females. Alternatively, selection acting on new mutations, and affecting linked neutral sites, could reduce variability on the Y chromosome. Here, using genome-wide analyses of X, Y, autosomal and mitochondrial DNA, in combination with extensive population genetic simulations, we show that low observed Y chromosome variability is not consistent with a purely neutral model.
study  gender  genetics  sapiens  pop-structure  male-variability  genomics 
october 2016 by nhaliday

bundles : patterns

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