What's wrong about cousin's love?

Question

I've read thruogh many similiar questions asking about this. Some say It's wrong and gross, U will get birth effects. Some say ignore the society, U won't get birth effects if blah blah blah... Can any real professional tell me what's wrong about cousin love, and is it ok in any way?

look, i know It's wrong in general. But in some countries, It's legal to do that. Is there any situations that U dont get birth deffects?

I dont quite get any of the answers below. Maybe I'm dumb. But can any of you give me some real life examples?

Answer 1

The only problem that will arise is the appearance of unusual birth defects in their baby. This is due to inbreeding.
When close relatives interbreed, the probability of the progeny to inherit two recessive alleles, and therefore, a possible mutant phenotype is greater! The baby might, therefore have certain defects, which would usually not be prevalent (repressed by dominant alleles) in an out-bred society.

Even after overlooking the norms of society, I cant really imagine a situation where marriages between close family members will have any advantages.

OKAY... I explain more simply. There are genes in people, that determine how the people will be.
Some features that people inherit from genes, will appear in them, only if two copies of the same defective gene come together in them.
The probability that these two copies of a gene will come together in a baby is much more if two people of the same family marry, because people of the same family have a higher chance of having the same defective copy of the gene.
Therefore, the baby will be at a greater risk of having birth defects.

As an example... There has been the history of a disease called Hemophilia in the British royal family, due to the coming together of two such defective copies of a gene.
Another example, is the strange jaw appearance of Austrian rulers. The "Hapsburg jaw" was commonly observed in the Austrian royal family... especially because Austrian royals intermarried in a close community.

Answer 2

There is nothing like "wrong in a genetic point of view" (timmy, above). We've been through that (Social Darwinism, eugenics).

As long as you don't inbreed for many generations, you'll stand no great risk for bad babies. Genetically, even first cousins are quite dissimilar. But was the question really about producing babies? It's about Love, and "all is fair in Love and Art".

Answer 3

Here is a very simplified answer:

Basically, you and I have all kinds of random mutations in our genes, but they don't show up because they are recessive. When you reproduce with somebody else, they don't have the same mutations, so there is a very low chance of two of the same mutation joining to become what is called homozygous. When you reproduce with someone inside your family, you share those genes in common, and those mutations are much more likely to become homozygous in your offspring. This would therefore allow a normally recessive (hidden) gene mutation to show itself. You would be surprised how many hidden (recessive) gene mutations people carry with them. They just don't normally show because mating occurs outside the family, with others who have a completely different set of hidden mutations.

Answer 4

it's wrong in a genetic point of view because if your family line is known to have certain diseases, having children could eventauly be very problematic. becuase now, your children will be more likely to inheirt that trait.

im not a professional but hope that helped..somewhat.

Answer 5

like they always say, if both of you are first cousins it is best to avoid the relationship.

Answer 6

Excerpt from Wikipedia "Incest or Inbreeding"...

The concepts of "incest" and "inbreeding" are not synonymous.

Incest refers to socially taboo sexual activity between individuals who are considered to be too closely related to enter into marriage. In other words, it is a social and cultural term.

Inbreeding, on the other hand, refers to procreation between individuals with varying degrees of genetic closeness only, regardless of their relative social positions. It is a scientific term rather than a social or cultural term.

In many societies, the definition of incest and the degree of inbreeding may correlate positively. For example, when sexual relations between people of a given degree of genetic closeness is considered incestuous. In other societies, the correlation may not be as obvious.

The consequence of inbreeding is to increase the frequency of homozygotes within a population. Depending on the size of the population and the number of generations in which inbreeding occurs, the increase of homozygotes may have either good or bad effects.

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Genetics

Table of prohibited marriages from The Trial of Bastardie by William Clerke. London, 1594.Inbreeding leads to an increase in homozygosity, that is, the same allele at the same locus on both members of a chromosome pair. This occurs because close relatives are much, much more likely to share the same alleles than unrelated individuals. This is especially important for deleterious recessive genes, which are harmless and inactive in a heterozygous pairing, but when homozygous can cause serious developmental defects. Such offspring have a much higher chance of death before reaching the age of reproduction, leading to what biologists call inbreeding depression, a measurable decrease in fitness due to inbreeding among populations with deleterious recessives. Recessive genes which can contain various genetic problems have a tendency of showing up more often if joined by someone who has the same gene. If a son who has hemophilia becomes intimate with his sister who may have the same gene for hemophilia, and they have a child, the odds are in favor that the child will have hemophilia as well. In short, when those that are related have children together, all of the recessive genes come out in their children.

Some anthropologists are critical of including biology in the study of the incest taboo, and have argued that there can be no biological basis for inbreeding aversion because inbreeding may in fact be a good thing. Leavitt (1990) is a good representative of this point of view, writing that "small inbreeding populations, while initially increasing their chances for harmful homozygotic recessive pairings on a locus, will quickly eliminate such genes from their breeding pools, thus reducing their genetic loads" (Leavitt 1990, p.974)

Other specialists claim that this notion betrays a misunderstanding of basic genetics and natural selection. They argue that, while technically possible, the proposed positive long-term effects of inbreeding are almost always unrealized because the short-term fitness depression is enough for selection to discourage inbreeding. Such a scenario has only occurred under extremely unusual circumstances, either in major population bottlenecks, or forced artificial selection by animal husbandry. In order for such a "purification" to work, the offspring of close mate pairings must only be homozygous dominant (free of bad genes) and recessive (will die before reproducing). If there are heterozygous offspring, they will be able to transmit the defective genes without themselves feeling any effects. What's more, this model does not account for multiple deleterious recessives (most people have more than one), or multi-locus gene linkages. The introduction of mutations negates the weeding out of bad genes, and evidence exists that homozygous individuals are often more at risk to pathogenic predation. Because of these complications, it is extremely difficult to overcome the initial "hump" of fitness penalties incurred by inbreeding. (see Moore 1992, Uhlmann 1992)

Therefore, it is not surprising that inbreeding is uncommon in nature, and most sexually-reproducing species have mechanisms built in by natural selection to avoid mating with close kin. Pusey & Worf (1996) and Penn & Potts (1999) both have found evidence that some species possess evolved psychological aversions to inbreeding, via kin-recognition heuristics.

Given such overwhelming evidence of inbreeding depression as being an important force in sexual reproduction, evolutionary psychologists have argued that humans should possess similar psychological heuristics against incest. The Westermark effect is one strong piece of evidence in favor of this, indicating that childen who are raised together in the same family find each other sexually uninteresting, even when there is strong social pressure for them to mate. In what is now a key study of the Westermarck's hypothesis, the anthropologist Melford E. Spiro demonstrated that inbreeding aversion between siblings is predicatably linked to co-residency. In a cohort study of children raised as communal, that is to say, fictive, siblings in the Kiryat Yedidim kibbutz in the 1950s, Spiro found practically no intermarriage between his subjects as adults, despite positive pressure from parents and community. The social experience of having grown up as brothers and sisters created an incest aversion, even though genetically speaking the children were not related.

Further studies have backed up the hypothesis that some psychological mechanisms are in play that "turn off" children who grow up together. Spiro's study is corroborated by Fox (1962), who found similar results in Israeli kibbutzum. Likewise, Wolf and Huang (1980) report similar aversions in Taiwanese "child" marriages, where the future wife was brought into the family and raised together with her fiancee. Such marriages were notoriously difficult to consummate, and for unknown reasons actually led to decreased fertility in the women. Lieberman et. al (2003) found that childhood co-residency with an opposite-sex individual strongly predicts moral sentiments regarding third-party sibling incest, further supporting the Westermark hypothesis.

While the exact nature of kin-recognition psychology is still waiting to be defined, and to what degree it can be overcome by cultural forces is as yet poorly understood, an overwhelming body of research now shows that evolutionary biology and evolved human psychology plays a central role in human aversion to incest.