Mating Systems

• There is reduced resistance to pests.

• There is a reduced lifespan in these organisms.

MATING SYSTEMS

A mating system involves the group structure necessary for sexual behavior. Among animals, mating systems describe how and under what situations the male and female may mate. In plants, the major mating systems are outcrossing, which involves cross-fertilization of organisms, autogamy, which is self-fertilization, and apomixis, which is essentially asexual reproduction. Fertilization can be random or may involve self-fertilization.

Animals have their own mating systems. In monogamy, there is one male and one female in an exclusive relationship. There are three types of polygamy in animal systems. In polygyny, which is the most common relationship, one male mates with more than one female but the females are all bound to the same male. In polyandry, one female has more than one male associated with her. This is very rare, except in honeybees. In polygynandry, a few males have sexual relationships with a few females. Another mating system is promiscuity, in which any male and female may mate. This is seen in chimpanzee relationships.

The mating relationship does not necessarily get associated with social or parental relationships. Sometimes, the male has no relationship with regard to parenting, while other times, the male is involved to varying degrees. In communal breeding, there is more than one male or female involved in rearing the young.

Even in pair bonding and monogamous relationships, there is a fair degree of out-pairings, which can be advantageous to the group by improving fitness or appearance of the young. In promiscuous or polygynous groups, paternal care is rare and some involve no parental care whatsoever. Mating systems can change, depending on the overall circumstances and system mixtures are common. Among humans, the majority of mating systems are polygynous, a few are monogamous, and even fewer are polyandrous.

Mating in bacteria involves the actual transfer of DNA from one bacterial cell to another with incorporation of the DNA into the genome. Transformation involves uptake of DNA from the environment. Transduction involves uptake of DNA by an infecting virus. Conjugation involves the transfer of DNA from one cell to another.

Archaea can practice a form of mating through forming cellular aggregates. There are bridges that occur between the cells that allow the exchange of DNA. Most protists do not form tissues