From Wikipedia, the free encyclopedia

Tortoises mating

In biology, mating is the pairing of opposite-sex or hermaphroditic internal fertilization animals for copulation and, in social animals, also to raise their offspring. Mating methods include random mating, disassortative mating, assortative mating, or a mating pool.

In some birds, for example, it includes nest-building and feeding offspring. The human practice of making domesticated animals mate and of artificially inseminating them is part of animal husbandry.

Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization. The two individuals may be of opposite sexes or hermaphroditic, as is the case with, for example, snails.

Newly evolved prehistoric animals initially lived only in water and reproduced by external fertilization in the water. About 450 million years ago, during the Late Ordovician, some animals^{[citation needed]} started migrating from oceans to the land, necessitating internal fertilization to maintain gametes in a liquid medium.

In some terrestrial arthropods, including insects representing basal (primitive) phylogenetic clades, the male deposits spermatozoa on the substrate, sometimes stored within a special structure, and courtship involves inducing the female to take up the sperm package into her genital opening; there is no actual copulation. In groups such as dragonflies and many spiders, males extrude sperm into secondary copulatory structures removed from their genital opening, which are then used to inseminate the female (in dragonflies, it is a set of modified sternites on the second abdominal segment; in spiders, it is the male pedipalps). In advanced groups of insects, the male uses its aedeagus, a structure formed from the terminal segments of the abdomen, to deposit sperm directly (though sometimes in a capsule called a "spermatophore") into the female's reproductive tract.

Many other animals reproduce sexually with external fertilization, including many basal vertebrates. Many vertebrates (such as reptiles, some fish, and most birds) reproduce with internal fertilization through cloacal copulation (see also hemipenis), while mammals copulate vaginally.

See also: Animal sexuality

In humans, unlike most animals, copulation may or may not be related to reproduction. In most cases people copulate for pleasure; this behaviour is also seen in some animal species, for example chimpanzees are known to copulate when the female is not fertile, presumably for pleasure, which in turn strengthens social bonds. See also sexual intercourse and human sexual behavior.

See also: Human sexuality

Like in animals, mating in other eukaryotes, such as plants and fungi, denotes sexual conjugation. However, in vascular plants this is mostly achieved without physical contact between mating individuals (see pollination), and in some cases, e.g., in fungi no distinguishable male or female organs exist (see isogamy); however, mating types in some fungal species are somewhat analogous to sexual dimorphism in animals, and determine whether or not two individual isolates can mate.

See also: Plant sexuality

A pair of lions copulating in the Maasai Mara, Kenya	Love bugs mating	Ladybug mating	Dragonflies mating
Butterflies mating	Anthomyiidae flies mating	Cockatiels mating	Herring Gulls mating

Wikimedia Commons has media related to:

Animal sex

• Introduction to Animal Reproduction
• Advantages of Sexual Reproduction