Why is it that if you have sex with a relative the baby is disabled?

Answer 1

Because the two people are related they have similar genes both good and bad genes(dominant and recessive). If these two people reproduce, their offspring is the result of two very similar gene pools which contain both good and bad genes. The likelihood that a person could inherit a bad gene from each parent is increased thus producing disabilities, etc.

Answer 2

Because both parents are related they have are larger number of genes in common then two strangers would. This is why I look like my sister and not like Paris Hilton (who thank god is not my sister). Babies get half of their genetic material from mom and half from dad. Thus, everyone has two copies (called alleles) for each gene. Inbreeding reduces heterozygosity, which means that the two alleles that code for a trait are different. Think of an imaginary disorder... if big A is dominant and little a is recessive, then both AA and Aa will result in a normal person while aa will have the disorder. In breeding results in more AA (which in this case is a good thing) and aa (a bad thing).... So, inbreeding in general is not bad, many domestic animal breeds resulted from inbreeding, but it can lead to problems (deaf dalmations)... Another phenomena is heterosis.... this is the opposite of inbreeding, it increases the amount of variation (think of it as the offsprings gets the best, or atleast dominat, traits from each parent) this is why many people think mutts are the best kind of dogs and most commercial farmers raise crossbred hogs. Human inbreeding resulting in disabled children may not necessarily be as much an issue of genetics as sociology. In today's society, incest is very taboo, and most people who do so are not playing with a full deck of cards and these disabled people may pass thier disabilites to their children just as they pass hair color.

Answer 3

man most of thes people do not have any clue in what they are talking about. Have you ever herd of dominite genes. Well when say a brother and sister have sex and have a kid, they may both have to same dominate gene. When you have double dominates the result is either the kid will die or it will have alot of problems. The genetic material is simalar but not the same. It is not always true you may have a perfectly healthy baby but the chances are lower then having a lover that isnt a relative.

Answer 4

Not totally true. Yes, genetics determine the outcome. but it doesn't mean that people related to one another will have disabilities. In racehorses, cattle, and even dogs, offspring are often bred back to parents or siblings to increase the stronger qualities. Still, you don't do this over and over throughout the bloodline. You do introduce new blood in occassionally. The same would hold true with people...strong traits bred with strong traits increase the likelihood of more or stronger traits. It could however, produce weaker or less desirable traits if present in both male and female. heck. in texas you can still marry you first cousin legally.

Answer 5

It's not a myth. The child is disabled because both of it's sets of genes are so similar that it does not get everything that it needs. A normal child's parents are usually so different genetically that the child gets everything it needs and more.

Answer 6

Greater diversity of genetic material increases the chances of having a healthy baby.

Answer 7

because the DNA in both parents are too similar and will cause birth defects and mental illness. There needs to be more diversity in the DNA to make a healthy baby.

Answer 8

if you have a weak gene in your dna... then close families may also have that weak gene...so when u have a child that weak gene does not get stronger material from another family line and therefore the weakness is multiplied and can result in a defect that u can see... eg u may have a few freckles and your brother have a few but if u both had a child he may be covered with freckles....hope this kinda explains

Answer 9

The entire subject is pretty complex so I recommend you stop by the attached link for much more information on Incest. See the bit on Genetics as well.

Hope this helps!

Answer 10

because having sex with a relative is a sin and God punish you.