GENETIC CONFLICTS, INTRINSIC MALE FERTILITY, AND EJACULATE INVESTMENT
Article first published online: 22 APR 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 66, Issue 9, pages 2685–2696, September 2012
How to Cite
Engqvist, L. (2012), GENETIC CONFLICTS, INTRINSIC MALE FERTILITY, AND EJACULATE INVESTMENT. Evolution, 66: 2685–2696. doi: 10.1111/j.1558-5646.2012.01641.x
- Issue published online: 4 SEP 2012
- Article first published online: 22 APR 2012
- Accepted manuscript online: 30 MAR 2012 04:30AM EST
- Received June 15, 2011 Accepted March 3, 2012
- individual-based simulations;
- mother's curse;
- segregation distortion;
- sexual selection;
- sperm competition
Few aspects of biology are linked to so many evolutionary conflicts as sperm production and fertilization. Segregation distortion and maternal inheritance of cytoplasmic genes, causing maladapted males, are common sources of variation in the competitive ability of sperm, leading males to vary in their intrinsic fertility. Here, I theoretically analyze the effect of such variation in male intrinsic fertility on ejaculate investment. The model reveals that with increasing variation in male fertility, males should overall spend less resources on their ejaculates. Furthermore, if males differing in intrinsic fertility are able to invest differently in sperm production, there are two contrasting outcomes. Typically, less fertile males should invest more. However, if female mating frequency is relatively low and differences between males relatively large, the most common male genotype should invest more. These results have important consequences both for the understanding of sperm competition strategies as well as for the evolution of female polyandry and female mating preferences.