Quote Originally Posted by Pioner
Quote Originally Posted by saibot
Great example! That is called selection! Natural, but in this case artificial selection. Organisms do not change because of the environment, that theory is wrong and called Lamarkism, not Darwinism. Neo-Darwinism (Darwinism + Genetics) speaks about selection. All of us got different variation of genes, which are quite stable, mutations are quite rare and they often useless or fatal, but some of them usefull. Anyhow, when cadmium did not exist, all worms were OK, but they some of them had genes of cadmium-resistence. Then environment changed and here we go, all useless (from evolution point of view) in current situation organisms died but those who had "right" genes survived. Look at Giraffes. Long ago they had normal necks. Let's say that 1% of them had slightly longer neck, guess what? They manage to get leaves better then other. They had higher chances to survive. So in several generations those with longer necks survived. Then it goes futher, out of them who had even longer necks survived. Etc. Looks simple, but it is complecated at the same time. Because long neck creates other comlecations for the organism. So out of longer neck giraffes survive those organism who had possibility to deal with high blood pressure etc. Evolution selects by many factors. Look at cars. Lets say there is an almost perfect car, powerful engine, great milage, great design, but horrible brakes? Who is going to buy that? Nobody. That car does not survive. People select cars which better value for a buck but with all needed stuff. Manufacturers of wrong cars do not survive, like many eastereropean manufacturers of cars disappeared.
Oh I disagree. Environment has a very big effect on organisms.

http://pubs.acs.org/subscribe/journals/ ... oxins.html

[quote:keru33fb]Evidence that the genes of developing fetuses can be permanently changed by exposure to compounds that act like hormones and that this effect is then passed on to future generations is sending shock waves through the ecotoxicology community. A study reported this week in June at the annual Endocrine Society meeting in San Diego, Calif., found that if pregnant rats were dosed with the fungicide vinclozolin or the pesticide methoxychlor, their young later suffered fertility problems. Further, this defect was passed on to future offspring, evidence that the chemicals had permanently reprogrammed the animals’ genetics.
DNA is a huge but nevertherless regular chemical molecula. And some chemicals effect it, changing it's structure, those chemicals are called mutagens. But, those changes are not directed, spontaneous, and does not develop resistence to that mutagen, unless by some luck there appear a mutation protecting against that. Mutagens increase variations in DNA, mutations, most of them fatal. But, things like, for example cold climate do not change genes that animals start to produce thicker fir. No, it is just so happen that animals with thicker fir have more chances to survive and produce babies with thicker fir. But environment does to change genom of animals directing it going in "right" direction. I hope I am clear here. Quite busy at my work right now.[/quote:keru33fb]

Ok. All the posts on the last 3 pages of this argument are all about nit-picky little details. We could sit here and argue all day about it, and get nowhere. You say something, I counter it, then you counter that. And so on.

So Im gonna make it broad again. In your example above, about developing thicker fur, that is natural selection. I have no problem with natural selection. But when does natural selection CAUSE evolution? Natural selection - change in allele frequencies. Nothing new added to the gene pool. Darwinism is defined as evolution THROUGH natural selection. I may be missing something here, but If nothing is added to the gene pool, when and how does a completely new species arise?