PolygynyPolygyny (pəˈlɪdʒɪni; from Neoclassical Greek πολυγυνία (); ) is the most common and accepted form of polygamy around the world, entailing the marriage of a man with several women. Polygyny is more widespread in Africa than in any other continent. Some scholars see the slave trade's impact on the male-to-female sex ratio as a key factor in the emergence and fortification of polygynous practices in regions of Africa.
CohabitationCohabitation is an arrangement where people who are not married, usually couples, live together. They are often involved in a romantic or sexually intimate relationship on a long-term or permanent basis. Such arrangements have become increasingly common in Western countries since the late 20th century, being led by changing social views, especially regarding marriage, gender roles and religion. More broadly, the term cohabitation can mean any number of people living together. To "cohabit", in a broad sense, means to "coexist".
Legitimacy (family law)Legitimacy, in traditional Western common law, is the status of a child born to parents who are legally married to each other, and of a child conceived before the parents obtain a legal divorce. Conversely, illegitimacy, also known as bastardy, has been the status of a child born outside marriage, such a child being known as a bastard, a love child, a natural child, or illegitimate. In Scots law, the terms natural son and natural daughter carry the same implications.
Polygyny in animalsPolygyny (pəˈlɪdʒɪniː; from Neo-Greek πολυγυνία, from πολύ- poly-, "many", and γυνή gyne, "woman" or "wife") is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.
Behavioral ecologyBehavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when studying animal behaviors: What are the proximate causes, ontogeny, survival value, and phylogeny of a behavior? If an organism has a trait that provides a selective advantage (i.e., has adaptive significance) in its environment, then natural selection favors it.
Sperm competitionSperm competition is the competitive process between spermatozoa of two or more different males to fertilize the same egg during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and variety of mates increases a female's chance to produce more viable offspring. However, multiple mates for a female means each individual male has decreased chances of producing offspring. Sperm competition is an evolutionary pressure on males, and has led to the development of adaptations to increase male's chance of reproductive success.
VoleVoles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of low-crowned with rounded cusps). They are sometimes known as meadow mice or field mice in North America. Vole species form the subfamily Arvicolinae with the lemmings and the muskrats. There are approximately 155 different vole species. Voles are small rodents that grow to , depending on the species.
PolyandryPolyandry (ˈpɒliˌændri,_ˌpɒliˈæn-; ) is a form of polygamy in which a woman takes two or more husbands at the same time. Polyandry is contrasted with polygyny, involving one male and two or more females. If a marriage involves a plural number of "husbands and wives" participants of each gender, then it can be called polygamy, group or conjoint marriage. In its broadest use, polyandry refers to sexual relations with multiple males within or without marriage.
DivorceDivorce (also known as dissolution of marriage) is the process of terminating a marriage or marital union. Divorce usually entails the canceling or reorganizing of the legal duties and responsibilities of marriage, thus dissolving the bonds of matrimony between a married couple under the rule of law of the particular country or state. It can be said to be a legal dissolution of a marriage by a court or other competent body. It is the legal process of ending a marriage.
Nuclear familyA nuclear family, elementary family, atomic family, cereal-packet family or conjugal family is a family group consisting of parents and their children (one or more), typically living in one home residence. It is in contrast to a single-parent family, the larger extended family, or a family with more than two parents. Nuclear families typically center on a heterosexual married couple which may have any number of children. There are differences in definition among observers.