Male alternative sexual strategies: When your not the biggest and the best. …or for that matter if your late to the party 1.Interference 2.Deception 3.Sneak copulations

Male alternative conditional sexual strategies: Marine iguanas Larger males will interfere with copulations Smaller males compensate with a pre-ejaculate of old sperm which seeps

The 3 male morphs with distinct reproductive tactics : 1.  -males are largest possess elongated uropods and comprise 81% of the male population 2.  -males are smaller than a-males, comprise 4% of male population resemble females in their behavior and external morphology invade spongocoels by mimicking female behavior; 3.  -males are smallest, comprise 15% of aggregate male population Use their small size and rapid movements to invade spongocoels (From Shuster 1992). Male morph differences are the result of genetic differences. Male inherited alternative sexual strategies: Paracerceis sculpta In order for three morphs to exist they MUST exhibit equal reproductive success

Do we have different and evolved sexual strategies? Phenotypic (conditional)? Genotypic (inherited)?

Males just don’t give up: Sperm competition The contest between sperm from two or more males for the fertilization of ova. 1.Penis morphology 2.Sperm morphology 3.Sperm concentration 4.Sperm motility and 5.Directional movement 6.Sperm longevity 7.Chemical composition of semen

Seychelles Brush-Warbler 1.Seychelles Brush-Warbler males vigorously guard females until they deposit their single egg 2.They then switch to egg protection and abandon mate guarding Does mate guarding affect mating success?

Mate guarding affects mating success: During female receptivity Experiment: 1.Place egg in nest to fool mate guarding males into switching to nest guarding 2.Measure extra pair male intrusions and copulations in control vs. manipulated Controls

Mate guarding DOES affect mating success Egg placed in nest

Mate guarding affects mating success: After the fact Many insect males ride on top of the female for prolonged periods of time after mating to discourage other suitors. Wheel Bugs Tiger beetles Millipedes

Do humans exhibit mate guarding behaviors? Buss DM. Human Mate (2002). Guarding.Neuro Endocrinol Lett. 23 (4):23-9. Men’s mate guarding, relative to that of women’s, is strongly triggered as a consequence of being mated to young and physically attractive women, being confronted by interested rivals who have superior economic resources or prospects, and having a mate who displays signs of sexual involvement with a rival. Women’s mate guarding, relative to that of men’s, is triggered as a consequence of being mated to men high in income and status striving, rivals who are more physically attractive, and having a partner who shows signs of emotional involvement with another woman. Behavioral output of mate guarding adaptations range from vigilance to violence.

Female mate choice: Its all about the looks?

Mate choice: Its all about the genes, looks are an indicator Good genes Healthy male Healthy offspring Better looking/behaving Fewer parasites Less predation Variability in looks/behaviors Variability in parasite succeptability Variability in predator defenses The cycle of consistent selective pressure for genes that indicate quality can cause runaway selection. Pre-sexual selection Sexual selection

Are we better looking that we were? Or just cleaner…