Sperm are similar to virus. Sex is evolution s brain in that it lets it try all the possibilities. Because the female contributes more she has more invested in the survival of the offspring. This is why she usually provides most of the care. Women s emancipation and empowerment corresponded with the shift from a society dominated by strength to one dominated by mind.
Females are physically weaker than men for the same reason there are different species.
Specialization of design allows greater conformity to the demands of the environment. Genes travel in gropes from parent to child and affect many different traits at once. Some genes are rare but most are common. People who look or seem similar share many genes. This is why you can infer things about someone from little clues or how they look.