Artificial selection. What exactly is this may you ask? Well, artificial selection is a human intervention in animal or plant reproduction to ensure that certain desirable traits are represented in successive generations. Basically, it alters a population for our personal benefits. This procedure is most likely used in agriculture, such as in the number of eggs laid by a hen, the meat property of bullocks, and the milk yield of cows. Other examples of artificial selection include the different breeds of domestic dogs and the large ears of maize corn. In fact, I'm sure most people aren't aware that broccoli and cauliflower are also on the list of products resulting from artificial selection. As you can see, cauliflower and broccoli come from the same ancestor, the wild mustard plant. These plants are full of vitamins and are accepted by everyone (well, except by those kids who don't like their vegetables ;D) because they are contributing to making everyone healthier.
The introduction of a new population isn't the only benefit that results from artificial selection, but it has also resulted in plants that are more disease resistant. In countries that are prone to pests like locusts, drought, or flooding, artificial selection would be beneficial to create crops that are both pest and disease resistant. As well as ones that would be able to withstand an excessive amount of rainwater or heat. This would help feed more people and create more money for those who need it, because through artificial selection one would be able to choose the desirable trait of having their crops be able to withstand these disastrous natural phenomenons.
Now, focusing more on animals. As I've stated before, artificial selection can be used for our benefits of creating more. As in, selecting pigs that will produce more meat, race horses that will run faster, or chickens to lay more eggs and/or to be more plump. Yes, we may benefit from getting more out of all of this, but this does have some downsides as well. Inbreeding is the potential danger that can result from too much artificial selection. Inbreeding decreases the heterozygosity in the gene pool, which can have potential problems. The limited gene pool caused by inbreeding can higher up the endangerment and extinction potential since is does not ensure variation. With the lack of variation, animals are more susceptible to diseases. Artificial selection can result in irreversible results that were not intended, but too late to change. Take this featherless chicken as an example. It was selected to have no feathers so that one wouldn't have to waste time plucking the chickens' feathers. Thus, saving a lot of time. Less time plucking, and more time creating more meat is the result! This featherless chicken also grows faster and larger than its ancestor. Yet, because it has no feathers, it has no protection to cover itself. Therefore this chicken is prone to more viruses and viral infections, be attacked by mosquitoes, susceptible to parasites, and dare I say it.. get sunburn! :O As well, featherless males will not be able to mate because they can't flap their wings. All these factors just show that featherless chickens will suffer more than normal birds do. This is just one example of a bad affect from artificial selection. Other examples would be dairy cattle, which are selected to produce more milk, but some lines now suffer from increased infection and fertility problems. Some Persian cats are bred to have extremely flat faces, but this often results in respiratory problems and trouble eating. These few selected traits that I've mentioned are not selected to help animals survive, but instead for the own selfish desire of the owner.
As you can see, there are both positives and negatives to artificial selection. Sure, it benefits us. But does it also benefit the plants and animals in turn? The answer to this is not always. Sometimes our desires get in the way, and we put ourselves ahead of everything. Which is not how it's supposed to be. Whether or not you are okay with artificial selection or not, or if you just feel indifferent about it, I don't know. In my opinion though, I think it is beneficial, but to a certain extent. We just need to learn where and when it is appropriate to stop. We just need to learn our limits.
Sources:
http://www.nextnature.net/2006/10/featherless-chicken/
