Speaking from a veterinary perspective, inbreeding is done more frequently than you would think. All pure breeds of animal (dog, cat, horse, cow, etc) have been inbred at some point. The general point of inbreeding is to ensure that good or desirable qualities stay in the genepool and are passed to the offspring. Still done today with animals. For example, dogs like Chihuahua frequently have hereditary eye problems. If you breed two sibling dogs that have good eyes and are genetically clear of it (as in not a carrier) then they won't have those eye problems. If you outcross to an unrelated dog that might have eye problems or be a carrier, then you run the risk of offspring having eye problems or carrying it. Though ya, of course things aren't THAT simple. At the same time, if you inbreed an animal where the lines and/or individuals have BAD genetic problems, then they will be still carried in and possibly exaggerated in the offspring. That's why when a random schmuck breeding their animals for money or for "cute babies" can lead to unhealthy puppies (inbreeding or not) while an educated breeder (again, inbreeding or not) can produce healthier animals. "Hybrid vigor" has it's merits, but as a fail-safe it's largely a myth.
As far as an evolutionary and species survival standpoint, inbreeding is discouraged because you'll then lack the genetic variety. Cheetahs are in the exact same boat with a lot of inbreeding. They had a genetic bottleneck and the species lacks genetic variety, leading to a lot of problems staying in the genepool and many of the cubs not even reaching their first birthday. There was a zoo near here that had cubs way back that required surgery when they were very young (a really bad infection), with one sister having an eye removed and the other having part of her tail removed. That's why a lot of wild cheetahs are either getting sent to captivity or have their sperm harvested in order to promote genetic variety between populations.
Just to toss this out there.
As for humans...hell if I have an opinion. In theory, I guess I don't care as long as it's consensual. If children are involved, that complicates things. I know people use that excuse with gays, but incest could potentially directly influence the physical HEALTH of the kid.
EDIT: Woman of Spartan ancestry getting her 300th post. This is a momentous occasion.
As far as an evolutionary and species survival standpoint, inbreeding is discouraged because you'll then lack the genetic variety. Cheetahs are in the exact same boat with a lot of inbreeding. They had a genetic bottleneck and the species lacks genetic variety, leading to a lot of problems staying in the genepool and many of the cubs not even reaching their first birthday. There was a zoo near here that had cubs way back that required surgery when they were very young (a really bad infection), with one sister having an eye removed and the other having part of her tail removed. That's why a lot of wild cheetahs are either getting sent to captivity or have their sperm harvested in order to promote genetic variety between populations.
Just to toss this out there.
As for humans...hell if I have an opinion. In theory, I guess I don't care as long as it's consensual. If children are involved, that complicates things. I know people use that excuse with gays, but incest could potentially directly influence the physical HEALTH of the kid.
EDIT: Woman of Spartan ancestry getting her 300th post. This is a momentous occasion.