Human sexual desire, human sexuality or simply human sexuality is the way in which people experience and express their sexual sexuality. Individuals engage in various sexual acts, ranging from spontaneous actions done with no special partner, to actions with another individual in varying frequencies, for various reasons. Some of these are mutually pleasurable while other causes emotional and physical discomfort.
Sex is an extremely complex behavior, one that involves both physical differences and psychological adaptations. It is very important that we recognize the important role sex plays in our lives. Sex is a major factor when it comes to selection of genes in humans. When a male and female mate and reproduce in the same environment, their children have a 50% chance of inheriting genes that are coded to indicate the gender that the offspring is, or was, born as. This is called sexual selection. Many theories suggest that sexual differences are the result of natural selection over the course of human evolution, with behavior being favored over biological adaptation in some cases.
Sexual differences can be caused by many factors including: genetic differences between individuals; differences in hormones; variation in body size or shape; and absolute sexual difference in height or weight. Body size and shape are influenced by differences in brain size between individuals. For example, men who have a smaller than average brain have been found to have smaller brains than women. Brain size and shape can also affect an organism’s abilities in movement, aggression or tool use.
Sexual differentiation, or the difference between the sexes, has also been found to depend on the primary function of the reproductive organ, which is, of course, the sex that an individual is attracted to. In humans, the main sex distinction is between the genders that normally mates. This distinction is also apparent in fungi, where sexual reproduction is triggered by the presence of specific compounds that only females have the ability to produce. The primary sex that does not reproduce can be either the same as the other, or different in both ways.
As an example, while most insects are sexual reproducers, the male ants are a different case, as their sperms do not engage in sexual reproduction. Male ants are “sexually inactive,” and engage in what is called “intercourse” with female ants on the nearby colony. However, when the queen is impregnated by the worker ants, the worker caste will eat the ants that are not its own, protecting the queen. Meanwhile, males prepare to undergo mating to produce a swarm of worker ants to defend the colony against other swarms of ant-invading fungi.
To summarize, in this main article, we discussed: the role of sex in gametogenesis; the role of gametes in sexual reproduction; and the role of gametes and sex in sexual differentiation. We looked at the role of sex in fertility and reproduction. And we looked specifically at how gametes are used by both males and females in sexual reproduction.