Tuesday, February 12, 2008
More Jews than Whites. What?
From Dienekes and gnxp, part of the conclusion of "Analysis of genetic variation in Ashkenazi Jews by high density SNP genotyping" (pdf):
There were small but significant differences in measures of genetic diversity between
AJ [Ashkenazi Jewish] and CEU [Utah whites from the HapMap sample]. Analysis of genome-wide LD structure revealed a greater number of haplotype blocks which tended to be smaller in AJ. There was essentially no difference in global LD decay between AJ and CEU, although there was a tendency for faster decay of nearby SNPs and slower decay of intermediate distance SNPs in the AJ. These data are more consistent with the AJ as an older, larger population than CEU, and would suggest that, depending on regional differences in LD structure, AJ populations may not always provide an advantage for whole-genome association mapping.
Re: the population sizes, would a more reasonable non-mathematical rendering be that the smallest AJ bottleneck was larger than the smallest CEU bottleneck, or the average AJ population size was larger than the average CEU population size?
And the Henry Harpending (you may remember him) replied:
Re Dan's question: either answer could be right. Instead of thinking about effective size think of the inverse of effective size, (1/Ne), which is the rate of diversity loss. This inverse can be averaged over time, like any speed. A bottleneck has a much larger effect on the average of (1/Ne) than it does on average Ne.
Will this put an end to the talk about a bottleneck in Ashkenazi history and about Ashkenazi disorders being the result of drift?
This is what is so exciting about widespread genetic testing: not only can we actually get answers for some old questions (are there different genepools within the human race? yes) we can ask questions that never would have occured to us before (what was the last year when Jews outnumbered whites?).
"(are there different genepools within the human race? yes)"
Then what? What happens after we figure this out? How could this information be useful to us? How could we apply such knowledge to current social or political issues? Give examples (If you dare)?
Posted by: Seerov | Tuesday, February 12, 2008
As I wrote before :
"To emphasize: political orientation, voting behavior, and partisanship all are partially determined by genetic heritage.
From a Systems Administration perspective, to the extent that the weight for or against perctain political orientations, voting behaviors, or partisan attachment are different between states, the "baseline" performance of those states will vary"
Posted by: Dan tdaxp | Tuesday, February 12, 2008
Not impressed by gnome view of social outlook. The expert should have been at my Mother and Father's diner table. Seven children. Reliable all children from same gene pool, Mom and Dad, being Mom and Dad. One end, 100% German, second or third maybe, generation in America Conservative Mom, Other end, Democratic half Irish half German, 2d or third generation on both sides Dad. I can never remember if the North side of the table was Conservative or Liberal because the South side was Liberal or Conservative. But in adulthood, my Sisters vote Dem except for ;once the third party guy from Tex, EDS. My three Brothers and I split Repub & Dem I think. One liberal sort of was Banker but not too hard on taxing the rich (he was a little banker). The other (now gone to the Great Conservative Heaven) thought Nixon was a Great Man in every way. I now know that neither Nixon nor any President is anything but an opportunist/pragmatist. Not much core in any.
Posted by: Robert C. Brenzel, Sr | Friday, February 15, 2008
I presume you meant "genome" instead of "gnome."
Political orientation appears to have about 50% of its variance explained by genetics [1,2]. Of course this leaves a lot out -- but .500 is a good batting average in any league!
Posted by: Dan tdaxp | Saturday, February 16, 2008
I thought Gnome was Genome in postings" license. You are right about 50% is good batting average. However it is a poor achievement as a mathmatical achievement for "predicting". It predicts half the time correctly. Like a coin toss?
Posted by: Robert C. Brenzel, Sr | Saturday, February 16, 2008
"You are right about 50% is good batting average. However it is a poor achievement as a mathematical achievement for "predicting". It predicts half the time correctly. Like a coin toss?"
Thank you for your clarifying question.
Variance is "is one measure of statistical dispersion, averaging the squared distance of its possible values from the expected value" 
For instance, consider the charts on this page . In particular, consider this scatter chart . If one would draw a line through it to try to estimate as many points as possible, you would get the next chart . That line would predict 72% of the variance. That doesn't mean datapoints fall on the line 72% of the time, and off of it 28% of the time. Rather, the line explains 72% of the "spread," leaving just 28% "error."
With regards to a lot of things (political orientation, intelligence, personality, etc), about 50% of the variance can be explained by heritable biological differences, about 10% can be explained by shared environment (the simple fact of having the same parents, etc), and 40% is "error" - we don't know yet.
Posted by: Dan tdaxp | Saturday, February 16, 2008