Percentage of significant tests in the (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) parameter space, for simulated data.

<p>We chose a range of 49 (<i>N</i>_f<i>m</i>_f/<i>N</i>_m<i>m</i>_m) ratios, varying from 0.0004 to 2401, and for each of these ratios we chose 29 sets of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values. By doing this, we obtained 1421 sets of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values, represented as white dots in the right-hand side panel B, covering the whole parameter space. For each set, we simulated 100 independent datasets using a coalescent-based algorithm, and taking the same number of individuals and the same number of loci for each genetic system as in the observed data. For each dataset, we calculated the <i>p</i>-value for a one-sided Wilcoxon sum rank test , and for each set of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values we calculated the percentage of significant <i>p</i>-values (at the <i>α</i> = 0.05 level). A. Surface plot of the proportion of significant <i>p</i>-values (at the <i>α</i> = 0.05 level), as a function of the female fraction of effective number and the female fraction of migration rate. B. Contour plot, for the same data. The dotted line, at which , represents the set of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values where the autosomal and X-linked <i>F</i>_ST's are equal. The theory predicts that we should only find in the upper-right triangle defined by the dotted line. Hence, the proportion of significant <i>p</i>-values for any set of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values in this upper right triangle gives an indication of the power of the method.</p

Diagram representing the relative values of expected genetic differentiation for autosomal markers and for X-linked markers .

<p>In the red upper right triangle, the <i>F</i>_ST estimates for autosomal markers are higher than for X-linked markers. In this case, <i>N</i>_f/<i>N</i> is necessarily larger than 0.5. In the blue region of the figure, the <i>F</i>_ST estimates for autosomal markers are lower than for X-linked markers. The white plain line, at which , represents the set of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values where the autosomal and X-linked <i>F</i>_ST estimates are equal. In this case , if <i>N</i>_f = <i>N</i>_m, then the lower effective size of X-linked markers (which would be three-quarters that of autosomal markers) can only be balanced by a complete female-bias in dispersal (<i>m</i>_f/<i>m</i> = 1). Conversely, if <i>m</i>_f = <i>m</i>_m, the large female fraction of effective numbers compensates exactly the low effective size of X-linked markers only for <i>N</i>_f = 7<i>N</i>_m. Last, if <i>m</i>_f = <i>m</i>_m/2, then the autosomal and X-linked <i>F</i>_ST estimates can only be equal as the number of males tends towards zero.</p

Sample description.

<p>Long., longitude; Lat., latitude. <i>n</i>_X, <i>n</i>_A, <i>n</i>_Y and <i>n</i>_mt: sample size for X-linked, autosomal, Y-linked and mitochondrial markers, respectively.</p

<i>p</i>-values of Wilcoxon tests plotted in the (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) parameter space.

<p>For each set of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values, we applied the transformation in eq. (4), and tested whether our data on autosomal and X-linked markers were consistent, given the hypothesis defined by the set of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values. (A) Surface plot of the <i>p</i>-values, as a function of the female fraction of effective number and the female fraction of migration rate, for the herders (11 populations). The arrow indicates the line that separates the region where <i>p</i>≤0.05 from that where <i>p</i>>0.05. Non-significant <i>p</i>-values (<i>p</i>>0.05) correspond to the values of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) that could not be rejected, given our data. (B) Contour plots, for the same data. The dashed line indicates the range of (<i>N</i>_f/<i>N</i>, <i>m</i>_f/<i>m</i>) values inferred from the ratio of NRY and mtDNA population structure, as obtained from the relationship: . The dotted lines correspond to the cases where <i>N</i>_f = <i>N</i>_m (vertical line) and <i>m</i>_f = <i>m</i>_m (horizontal line). (C) and (D) as (A) and (B), respectively, for the agriculturalists (10 populations).</p

Geographic map of the sampled area, with the 21 populations studied.

<p>Bilineal agriculturalist populations are in blue (Tajiks); Patrilineal herders with a semi-nomadic lifestyle are in red (Kazaks, Karakalpaks, Kyrgyz and Turkmen).</p

Level of diversity and differentiation for NRY markers and mtDNA.

<p>We calculated the total allelic richness (<i>AR</i>) (over all populations) and the expected heterozygosity <i>H</i>_e<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000200#pgen.1000200-Nei1" target="_blank">[55]</a> using Arlequin version 3.1 <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000200#pgen.1000200-Excoffier1" target="_blank">[56]</a>. Genetic differentiation among populations was measured both per locus and overall loci, using Weir and Cockerham's <i>F</i>_ST estimator <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000200#pgen.1000200-Weir1" target="_blank">[57]</a>, as calculated in Genepop 4.0 <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000200#pgen.1000200-Rousset2" target="_blank">[58]</a>. We calculated the total number of polymorphic sites, the unbiased estimate of expected heterozygosity <i>H</i>_e<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000200#pgen.1000200-Nei1" target="_blank">[55]</a>, and <i>F</i>_ST using Arlequin version 3.1 <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000200#pgen.1000200-Excoffier1" target="_blank">[56]</a>.</p

Human sex-specific demography inferred from genetic data.

<p>This table summarizes the observed patterns of sex-specific differences in demographic parameters reported in a number of recent studies. The first column lists the location of the sampled populations, or indicates whether the study is conducted at a global scale. The second column gives the markers used, and the third column indicates the statistical methods employed. The fourth column provides indications on social organization, available a priori for the populations under study. In the fifth and sixth columns, the authors' interpretations of sex-specific differences in demographic parameters are given, with respect to skewed gene flow and/or effective numbers.</p>a<p>Indications on social organization, marriage rules, etc., as provided by the authors.</p>b<p>The differences in demographic parameters between males and females, as inferred by the authors, are given in terms of sex-biased gene flow, and skewed effective numbers; the authors' interpretation to the observed pattern is given in parentheses, when available.</p>c<p>Single nucleotide polymorphisms.</p>d<p>Analysis of molecular variance <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000200#pgen.1000200-Excoffier2" target="_blank">[69]</a>.</p>e<p>Not available (no detailed information given by the authors concerning social organization, marriage rules, etc.).</p>f<p>Short tandem repeats.</p>g<p>Time to the most recent common ancestor.</p>h<p>mtDNA and NRY were not sampled in the same individuals or populations.</p>i<p>The authors discussed a possible difference in demographic parameters between males and females, but considered it as negligible.</p>j<p>The authors did not consider this pattern.</p>k<p>Food-producer populations.</p>l<p>Hunter-gatherer populations.</p>m<p>Monte Carlo Markov chain method to estimate population sizes and migration rates <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000200#pgen.1000200-Beerli1" target="_blank">[70]</a>.</p>n<p>Variance in Reproductive Success.</p>o<p>population-mutation parameter.</p