They then showed that older women recombine more than younger women; that higher recombination correlates with higher fertility; and that a large inversion on chromosome 17 is at present under positive evolutionary selection in European populations, with carriers having higher recombination and fertility rates than non-carriers.  A second recombination map published in 2010 utilized 300,000 SNPs and revealed different recombination hotspots between women and men, as well as novel genetic variations that affect recombination rate, and that do so differently in European and African populations.