Copulation: Encyclopedia - Copulation

Copulation

Copulation is the union of the external sexual organs of two sexually reproducing animal organisms for insemination and for subsequent internal fertilization, which is fertilization of ova inside organisms. The two organisms may be of opposite sexes or hermaphroditic, as is the case with, for example, snails.

Animals initially lived only in water and reproduced by external fertilization in the water. Certain animals started migrating from oceans to the land during the Late Ordovician epoch about 450 million years ago, so they started reproducing through internal fertilization. This maintained gametes in their originally liquid medium.

One example of animals which reproduce through internal fertilization are insects. The female insects that copulate receive the spermatophores from the males' aedeagi through their ovipores.

Many other animals reproduce sexually with external fertilization, such as the low vertebrates (catfish and most amphibians). Middle vertebrates (fish other than catfish, reptiles and most birds,) reproduce with internal fertilization through cloacal copulation (see also hemipenes), unlike higher vertebrates, which copulate vaginally.

As for humans and their related hominids, the terms sexual intercourse, making love, having sex and coitus are usually used, and also, vulgarly, the term fucking, which is derived from the Proto-Germanic language. In a wider context, the term sexual intercourse may refer to a wider range of sexual activities than the term coitus, which only means vaginal intercourse. See human sexual behavior for a discussion of the broader sense of sexual intercourse.

See also

• Reproduction
• Sexual arousal
• Sexual intercourse

Adapted from the Wikipedia article "Copulation", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki