think about what the fish would have to do -- it would have to realize what the problem was, what change would solve it, and then command its body to make that

think about what the fish would have to do -- it would have to realize what the problem was, what change would solve it, and then command its body to make that change, all without the benefit of any scientific knowledge. If we could do those sorts of things, we could solve a host of genetic diseases without medical science. The central problem for Lamarckism is explaining how the body is supposed to know which changes are beneficial. A blacksmith might develop a strong right arm, but also tennis elbow.