Question about incest?

Question

Why is it that if brothers and sisters/close relatives reproduce...the baby can come out "unhealthy"

Answer 1

Deformities, or any congenital diseases, are not guaranteed unless both parents are homozygous. They also do not pop up out of nowhere. If two people breed, and neither one has a gene for red hair, their children will never have red hair. Ever. Maybe with a random mutation, but not if everything goes as "planned."

If siblings both have genes Aa, and they have a child, that child has a 25% chance of getting gene aa. This does not mean that if they have 4 children one must have this gene. It means a 25% chance every time.

If siblings both have genes AA, they will never have a child with gene aa. They will never have one with Aa. Only AA.

Now then: why does inbreeding increase the CHANCE of a bad gene popping up?

Two unrelated people, one with gene AA and one with Aa, have two children. The children both have Aa.

Those two children have a child. Now you have the chance for a child with aa, where you didn't before. If this child, with aa, has a child with its parent, which has Aa, the chance of another aa child doubles. THIS IS NOT GUARANTEED. JUST A CHANCE.

And, of course, you can easily run into someone totally unrelated to you who also carries a defective gene, and your child with them can express the defective gene. Having kids with people outside your family tree is no guarantee your kids will be healthy.

Answer 2

Sibling's dna have the same defects in them.  So, when a baby is produced with the same dna, they are more likely to have these defects, and anything else wrong with a family's dna.

Answer 3

Look at it this way, your Father has A,B,C genes and your Mother has C, D, E, genes. Therefore the children depending on how many they have, let us say two, will have boy, A, B, Cc and girl, Cc, D, E, so both will carry an extra c gene. The c gene might not mean anything, or it might be a recessive gene for say Cancer. If the sibling then reproduce, the off spring will have Bb, Cc, Cc, Ee, so will probably die young from Cancer, or perhaps the Bb will mean the baby will be born without legs, arms, even a brain. To try and stop all these recessive genes, they do not allow certain family members to reproduce. Therefore the recessive gene remains dormant. Hope that helps.

Answer 4

A baby born from any incestuous relationship only has a 7% chance of having any kind of birth defect. That means that 93% of all babies born as a result of incest are perfectly fine and healthy.

Answer 5

Genetic defects.

x3

Simple and brief.

Answer 6

the whole point of having s*x is to mix genes and reproduce...

when a brother and sister get it on, since they are so closely related, their genes are almost identical, or have similar properties. thats were the unhealthy part comes into it, becau there is no mixing involved.  

Answer 7

You keep the gene pool small and that results in genetic defaults. Ever wondered why some kings and queens in the old days were a little bit crazy? It's because sisters married cousins, brothers, fathers. Oo Bad idea