The definition of communication is complex and somewhat controversial. We'll explore why that's the case, and then move on to some neuronal mechanisms enabling effective communication.

Different species have different mating systems that characterize the primary (though not solely) means under which reproduction occurs. Here, we examine perennial & seasonal monogamy, polygamy, including polygyny & polyandry, and promiscuity, including lekking species. Human mating systems are culture-specific.

An examination of 3 reasons why some species of nonhuman organisms breed synchronously: Optimal Resource Availability; Social Foraging; and, Avoiding Predation.

An examination of sexual selection in relation to speciation, including runaway sexual selection and sensory exploitation.

Deleterious effects of inbreeding in lions, and mechanisms of incest avoidance in zebra finches via female choice of male song, and incest compensation in shore birds via extra-pair mating.

When it comes to sexual selection, males court females, and females choose with whom to mate (with a few exceptions). Thus, female choice of mate is critical, and here we describe examples of this as well as related phenomena such as the Handicap Principle, disruptive selection, and sexual dimorphism not caused by sexual selection.

Males compete for females in a variety of ways: competitive mate searching, various mechanisms of sperm competition, and overt conflict. This screencast portrays each of these with a variety of examples.

The Darwinian concept of sexual selection, explored through examples of sexual dimorphism, how females can benefit by being choosy when selecting a mate, what cues females might use to assess potential mates.

Pheromones are semiochemicals that typically communicate within a species for such purposes as territory marking and sexual behavior. Occasionally, they might operate between species, as we'll see in this screencast.

Allelochemics are semiochemicals (i.e., chemicals that have either communicative value or anti-predator benefits) that communicate between different species. Three subclasses of allelochemics are allomones (that benefit the sender), kairomones (that benefit the receiver), and synomones (that benefit both the sender and receiver). Examples are shown of each of these substances.