Quo vadis homine? Or where the marriage goes?

Individuals are consanguineous if they are descended from a common ancestor no more remote than a great, great grandparent. The progeny of consanguineous parents are regarded as inbred. Within a particular society, the population structure and social customs determine the frequency of consanguineous mating; certain marriage requirements as set forth by the church and/or state, are designed to prevent very close mating. Inbreeding of domestic animals can preserve and fix desirable properties and eliminate unfavorable characteristics from livestock. Closely related animals may be mated to produce pure breeds of animals and select offspring of specific desirable types. However, because homozygote is less fit than heterozygote, inbreeding over a long period risks the loss of vigor in the offspring. Similarly, plants are inbred for improved characteristics, either by self-pollination or crossing with closely related plants. The situation in humans is far more complex. Genetic effects of inbreeding can be detected in the inbreed individual, in the form of gene doubling. Affected genes appear as a single line in each of the common ancestors but double in the progeny. In other words, modern genetic technology allows us to show how consanguinity reveals recessive inheritance and recessive traits. One means of reducing the accumulation of undesirable or potentially dangerous genetic material in human population is to prevent conception. Same sex marriage, legalized in some countries, does not produce children and is thus exempt from consanguinity restrictions. If same sex marriage became universally legal, mating among close cousins, or even brothers or sisters, uncle and nephew, and aunt and nice. A same sex marriage without the possibility of conception is the most efficient way to control reproduction, but this idea is not universally accepted. In the first place, only a small percentage of the population would likely be affected, since the heterosexual population is much larger than a homosexual one. Secondly, and more importantly, many people consider a homosexual relationship to be an unnatural, even evil. It thus becomes increasingly difficult to predict in which direction marriage will go.