Nagraj said:
Sdaji said:
inbreeding effects don't increase indefinately over successive generations.
Inbreeding depression is a well documented phenomenon. Perhaps I'm misunderstanding your statement?
Inbreeding effects don't
increase indefinately over successive generations. Inbreeding depression certainly is a phenomenon which exists, but it can't continue to increase with each generation indefinately because eventually all genetic variation is lost, so each generation is identical. This is a well known and understood phenomenon (lab mice and rats are brilliant examples and there is no shortage of lab studies on them!). Probably the most well studied example is Drosophila melanogaster, new inbred lines are routinely produced many, many times each year in countless labs all over the world. There are many thousands of papers in scientific journals documenting these studies, some of my friends have carried some of them out. In some cases/species/populations, inbreeding depression doesn't occur at all at any stage. I could write several pages on the topic, but when I used to do that sort of thing around here it wasn't greatly appreciated :lol:
Interestingly, in some cases, it is possible to get two inbred lines of animals which are perfectly healthy, each can be inbred indefinately without any problem at all, you can cross them and the first generation can be perfectly healthy, but if those offspring are bred to each other, or bred back to members of the original lines, there can be severe inbreeding depression. A very similar situation exists with naturally occuring populations (either different populations of different species/subspecies or even just different populations of what would generally be called the same subspecies) which are crossed to produce healthy hybrids, but the next and subsequent generations can be mildly to severely affected by inbreeding depression (which is caused by the initial outbreeding). Outbreeding depression (crossing individuals from different populations/taxa) is also a well documented phenomenon. Rennie: for this reason, you'll be better off keeping mouse lines seperate, although in all liklihood you'll never run into a problem with inbreeding or outbreeding depression in the mouse lines which are widely available, no matter what you do.
Okay, I've probably already exceeding the readable length of a thread, and said I wouldn't go on for too long, so I'll stop there