Y-chromosomal to autosomal STR variance

This may be relevant to Peter Frost's theory which I blogged about earlier.

Averaged over regional populations and over Y chromosome loci, the ratio equals 1.14, 0.51, 0.97, 0.93, 1.06, and 0.61, respectively, for sub-Saharan African hunter-gatherers (the number of populations, k, is 3), sub-Saharan African “farmers” (k=3), Eurasia (k = 21), East Asia (k = 18), Oceania (k = 2), and America (k = 5). Outlying values for American and sub-Saharan African farming populations, 0.61 and 0.51, may indicate lower effective population size for males than for females in these populations.

Source: The Effective Mutation Rate at Y Chromosome Short Tandem Repeats, with Application to Human Population-Divergence Time (PDF)