My goodness, this thread is insane. Breeding for a thousand generations won't necessarily acheive anything, those reticulated pythons weren't bred selectively for temperament! This helps kill the other argument (I shouldn't even give it enough credit to call it an argument) that becoming docile is merely an artifact of being in captivity.
For sure scientists get things wrong, but in those cases, it is poorly understood or newly discovered concepts. The concepts being discussed here are so well understood, all scientists agree on them, anyone who becomes familiar with it can clearly see it. The fact that geneticists may argue about the function of telomeres or the role of natural killer cells in the body's prevention of cancer doesn't mean that they are less certain about the basic concepts such as the action of Mendelian genetics or the fact that behaviour has a very heavy genetic influence. This isn't one of the cutting edge branches of genetics, this is an old concept which has well and truly been researched until well after the cows have not only come home, raised families and died. Yes, if returned to the wild with sufficient genetic diversity, any species previously bred to be tame will revert to its normal wild state over a few generations, because it is in the wild, with natural selection acting, which will take it back to its natural genetic makeup.
This thread is so silly :lol:
Inny, as Hix said, docile snakes may be better off than nasty snakes, in some cases. This idea is more complex than you suggest. Evolution doesn't always act directionally. Some traits are selected for in a negative frequency dependant way. I'll try to put it in a nut shell with an hypothetical example... A species of bird can eat two types of food. If it has a broader beak it can open one type, if it has a longer beak it can reach into gaps and collect another. If it is intermediate it isn't much good at either and selection has produced a genetic makeup which will throw each individual one way or the other. The trait is genetically determined. When too many individuals have broad beaks, the narrow beaked birds will have more food available per bird, they'll have more babies per bird than the broad beaked ones, their genotypes will be more greatly represented in the next generation, this will continue until the broad beaked birds are rare, then each of them will have more resources, etc etc etc. Neither genotype is lost. There are squillions of real examples of this concept, behavioural and morphological, in a wide range of animals including herps, which are well known, well studied and not in dispute. This is only one of many ways in which genetic diversity is preserved. If animals are brought into captivity and subjected to artificial selection, or if wild conditions facilitate it, one or more 'genotypes' (here I speak conceptually and colloquially) may become extinct.
Oh, Olive, the distance between the eyes is a quantitative trait with a genetic component, so it can be selected for!
Looks like you have to agree with me after all!
Whether or not you should listen to sellers' claims is another story. I don't believe there are many people at all anywhere in the world who have properly selected for temperament in snakes and agree that such claims should be taken with caution. Whether it can be done and whether it has been done in those particular cases are two very different issues, which should never be confused. Please don't mistake what I'm saying for supporting any of those claims, if it is still unclear, I don't suggest that anyone takes ads' claims at face value.
Hix: wow, someone agrees with me... freaky. By the way, I think we can be dead certain that more than one gene is involved in snake temperament
Obviously environmental influences are important, nature vs nurture and all that jazz.
It is probably important to somewhere in this thread point out that selective breeding, if it is to be done properly, is not merely getting two snakes, breeding them, getting the best of those babies, breeding them and so on. Among other things, you need a larger sample size than one or two pairs of founding snakes to get the best results and if a small sample is used, you'll rapidly run out of genetic variation and selection will have no further affect on that line. To explain it fully would require too much time and background knowledge, but the priciples involved with temperament selection are the same as selection for traits we're all familiar with, such as pretty yellow colours in jungle carpets.