  A series of studies have revealed the among-population components of genetic
variation are higher for the paternal Y chromosome than for the maternal
mitochondrial DNA (mtDNA), which indicates sex-biased migrations in human
populations. However, this phenomenon might be also an ascertainment bias due
to nonrandom sampling of SNPs. To eliminate the possible bias, we used the
whole Y chromosome and mtDNA sequence data of 491 individuals from the 1000
Genomes Project Phase I to address the sex-biased migration dispute. We found
that genetic differentiation between populations was higher for Y chromosome
than for the mtDNA at global scales. The migration rate of female might be
three times higher than that of male, assuming the effective population size is
the same for male and female.
