This applies to all sexually-reproducing species, not just humans. The male <i>strategy</i> is optimized for low cost, so males <i>prefer</i> to mate with a fit female, but will settle for &quot;anything with a pulse&quot;. In humans, this is evidenced by virtually all women having babies.<p>I don&#x27;t know what the actual ratio is, and it will probably be different depending on the fitness of the male and how near the bar&#x27;s closing time. The salient aspects are that the division is asymmetric, the strategy complements the female strategy, and that there is a hard cutoff (some of the females are so unfit they will never be considered).