Дел од дискусијата:
Andrew said... >how does proximity to Byzantium (a Greek city) help one resolve the problem that Albanian lacks Greek loan words.
It does not address it at all. The question is whether we are sure that Albanian V13 comes from areas of Greece known to have high V13 diversity. You said that no one believes Albanians could come from the East, which is an example of another direction you could get to Albania from areas closer to Asia. I just pointed out that this is not quite correct. They could have come from the East - perhaps via the north. Remember V13 had a long time to get to Albania.
>there was no part of Thrace really outside of Greek influence.
There was no part of the Balkans outside of Greek influence during some periods. Are you truly arguing that the Albanian language comes from outside all areas ever under Greek influence? And only based on loan words? Latin and Slavic also have many Greek loan words.
Genetic drift could certainly account for less diversity in Albania compared to Greece, but there are so many ways this could have happened - populations going up and down over centuries, and also emigration, an expanding dissipating population, not only immigration.
I also don't see how you've confronted my very simple question about whether concentrating any population into a smaller geographical area, will not always lead to that population looking "older" based upon normal measures of genetic diversity whenever we talk about a star shaped cluster like this.
Best Regards
Andrew
Авторот на блого одговара:
There was no part of the Balkans outside of Greek influence during some periods. Are you truly arguing that the Albanian language comes from outside all areas ever under Greek influence?
While pretty much most of the Balkans had
some Greek influence, the
degree of Greek influence is not the same.
Now, if the Albanians lived in their present-day location (northwest of Greece by the Adriatic) for a long time, their language would have both sea-related terms and ancient Greek loan words, since the Greeks were in that area for 3ky.
This problem would not be solved if one was simply to laterally move their origin to the east in Thrace, as the same problems would arise.
The location of the early Albanians is to be sought to the northeast of their present-day location, in the interior of the Balkan peninsula, somewhere where (i) they wouldn't be close to the sea, (ii) wouldn't be close to Greeks.
Genetic drift could certainly account for less diversity in Albania compared to Greece, but there are so many ways this could have happened - populations going up and down over centuries, and also emigration, an expanding dissipating population, not only immigration.
No, emigration can't realistically affect Y-STR variance. Read the post on how bottlenecks affect Y-STR variance. Emigration is equivalent to a bottleneck; the only difference is that the population doesn't die or fail to reproduce but moves out.
I also don't see how you've confronted my very simple question about whether concentrating any population into a smaller geographical area, will not always lead to that population looking "older" based upon normal measures of genetic diversity whenever we talk about a star shaped cluster like this.
Let
a be an allele, let
ma be the mean allele, let
ma1,ma2 be the mean alleles of two subpopulations.
Variance is an average of terms of the form:
(a-ma)^2.
For an allele of one of the subpopulations (e.g. 1), this can be written as:
(a-ma1+ma1-ma)^2 =
(a-ma1)^2+(ma1-ma)^2+2*(a-ma1)*(ma1-ma) (Eq. 1)
(replace ma1 with ma2 for the second population)
The variances in the subpopulation is an average of terms of the form
(a-ma1)^2
(a-ma2)^2 (Eq. 2)
Now, if the two subpopulations are not differentiated, then for most loci ma1=ma2=ma. Hence, from (Eq. 1), the variance of the composite population will be an average of terms:
(a-ma1)^2 and (a-ma2)^2
If you do the math, and VAR, VAR1, VAR2 are the variance in the total, population 1, and population 2, then
VAR = f1*VAR1+f2*VAR2 (Eq. 3)
where f1,f2 are the fractions of the two populations in the composite population. From this it follows that VAR less_or_equal max(VAR1,VAR2).
In a star cluster ma1 approx_equal ma2 for most loci, hence the result of admixture will not increase the variance above that of the higher-variance population, but will result in an intermediate variance value (Eq.3)
If, on the other hand there is no star cluster but the two populations form their own clusters, then ma1 will be different from ma2 in several loci and the (ma1-ma)^2 term (Eq.1) won't be zero => increased variance.
Ова на некој начин е и одговор за Silen на кого не му беше јасно Генетик дрифтот.
