Why would breeding dogs support Darwin's theory of evolution by natural selection?

Answer 1

Selective breeding supports Darwins theory because, we adapt to our environments and believe whoever is compatible with breeding will pass on the trait, even if that means outside their own species.

Answer 2

I assume you are asking about the Darwinian idea of evolution and if this is the case you will find a very thorough and interesting answer to this question in Chapter 1 of The Origin of Species the famous work of Charles Darwin. I can however give you a more brief, although significantly less eloquent, answer.

Selective breeding is the process used by domestic breeders to improve the characteristics of their population. Darwin uses the example of breeding pigeons. A good breeder will only allow specimens with the most desirable outward characteristics to reproduce. In this way the favourable characteristics are preserved and the less favourable characteristics become less prominent in the population. This process provides evidence that their is a degree of inheritance between parent and offspring. When we contemplate this process over a period of what is known as deep time (long time periods) we can appreciate that, by breeding out undesirable characteristics, it is possible to change the animal entirely.

At the time of publication Darwin's ideas were considered to be fairly controversial. Many believed that God had created and breathed life into every immutable variety of creature in its unchanging and perfect state. Darwin discusses selective breeding because it demonstrates in a familiar context that change through inheritance is possible and this is fundamental to the principle of natural selection or evolution.

The limitation of this model is that selective breeding can only be carried out to preserve the outwardly visible characteristics which are considered desirable by the beholder. Evolution or natural selection goes further than this. Natural selection recognises that any variation however slight, irrelevant of its outward visibility, which gives an animal an advantage over others of its kind will make that animal more likely to survive and therefore more likely to procreate.

Selective breeding supports the idea of inheritance and the struggle for survival suggests that only the fittest animals will survive and breed. Combining these ideas gives weight to the theory that only characteristics favourable to the species will be preserved, thus the species will evolve. In its extreme this supports the idea that no species is immutable. A species without desirable characteristics for survival in any particular environment will become extinct.

Darwin only identified this process of evolution he could not explain inheritance. It was the work on DNA carried out by Crick and Watson which completed Darwin's explanation.

Answer 3

Under artificial selection, selecting traits that are considered desirable to the breeder, Darwin had a powerful and easily understood analogy for the process of natural selection. With the environment being the selector of variant organisms, just as the dog breeder picks the best of the litter, Darwin could show that over time organisms would evolve under the selection pressure of the environment; natural selection.

Answer 4

Darwin studied other examples of changes in living things to help him understand how evolution might occur. One example that Darwin studied was the offspring of animals produced by selective breeding. English farmers in Darwin's time used selective breeding to produce sheep with fine wool. Darwin himself had bred pigeons with large, fan-shaped tails. By repeatedly allowing only those pigeons with many tail feathers to mate, breeders had produced pigeons with two or three times the usual number of tail feathers. Darwin thought that a process similar to selective breeding might happen in nature. But he wondered what process selected certain traits.