When Yes means No
My first festival event was When Yes Means No, or how females control male reproductive success, with a presentation by Professor Neil Gemmell of the Centre for Reproduction and Genomics. It was out at Invermay in Mosgiel.
He talked about the costs of sexualmating such as the time and energy and how competition hinders finding a suitable mate, plus risk of disease, and risk of homozygosity of dangerous recessive genes.
Almost enough to put you off sexual mating, except for the benefits of which are genetic recombination helps create variety, and sexual reproduction produces gene combinations better able to cope with parasites and predators. So overall seems a better deal than asexual reproduction (no that isn’t what you do in hotel rooms with adult movies).
Females in most species invest more in offspring due to eggs, gestation, lactation and infant care. This means that women’s sucess tends to be dependent on resources for offspring and their prospects are not enhanced by mating with multiple males.
However males (not just humans) increase their success by mating with multiple partners.
Females tend to value heterozygosity in their offspring and under some conditions in their males also. They are more attracted to mates who have different genetics.
One study has shown that symmetry in faces is important for short-term mating when females are fertile. Also females prefer more masculine faces when they have a partner and they are fertile.
Being on the pill affects woman significantly. For example pill users more affected by dis-similar odour.
Another study has shown that human couples share fewer MHC genes than expected by chance – there are higher miscarriage when similar. Also those with similar genes are more likely to be unfaithful. So you might ant to DNA test your partner.
One amusing throw-away line was about how ducks are basically rapists – and you should shoot them.
The female’s body favour certain types of sperm and bias in their favour. They will reject sperm of sub-dominant male but retain high status male.
Back to the pill, and how use of the pill can disrupt the mate preferences such as odour and symmetry but also attractiveness to men, so disadvantaged compared to women not on pill. This means that if you are on the pill, not only will you find fewer men attractive, but fewer men will find you attractive.
This was confirmed by a study of lapdancer tip earnings based on ovulatory cycle – the results were significant when fertile – $350 vs $200 earnings for those on the pill vs those not on the pill.
Was a fascinating lecture with some good q+a afterwards. The person next to me at the lecture is engaged, so I told her she should go DNA check her partner before the wedding, to see how likely he is to cheat 🙂