I want to clairfy something: Is it true that without DNA mutations it would be impossible to start with a population of x wild wolfs and breed a chihuahua, or poodle? Lets say your only goal is to start with a very large population of wolfs who on average weigh 100 lbs, your goal is to create a dog that has an adult weight of 5 lbs, and lets say you are controling the evironment ect, so that no DNA mutations would occur. Would it be impossible to create a dog of that size unless you started out with a dog that size? Assuming no mutations if you start with a trillion wolfs and divide the population into a billion groups of 1000 and breed the smallest male and female from each group and they had 10 puppies each and you continued this until you were down to a final group siblings of puppies with the same parents is it possible that the smallest wolf could be 5 pounds, even though the smallest from the original trillion was say 80 pounds? It seems possible if each generation got smallest size set of contributing genes from each parent. Like if generation 1 got the combination of genes from their parents which is as small as possible, so that if you compare the size contributing genes of the father and mother and pick the ones from each that will contribute most to small size (one parent may be genetically bigger overall but they may have certain genes which contribute more to small size than the other parents versions of those genes). This would require that the genes for a 5 pound dog were somewhere in that origional population although they may be scattered amongst thousands of dogs. Is this how dog breeding works, because I find it improbable that enough mutations could have occurred to say create a chihuahua or poodle, in the 10,000 years since dogs first became domesticated by humans. Another question: is it possilbe for 2 siblings to get an identical set of genes from their parents, without being twins, for example two siblings born years apart which got the same exact genes? Do you know of an example where this has happened?