When
we were first introduced to Darwin's cousin and oh yeah future WIFE, Emma, he
brings up the topic of artificial selection. He started talking about dogs,
which are one of the most common examples of artificial selection. Campbell's
Biology defines artificial selection as, "the selective breeding of
domesticated plants and animals to encourage the occurrence of desirable
plants." But what is a desirable trait? It can be anything, making fruit
sweeter, making dogs shed less, or even making a plant less susceptible to
insect activity. By looking at examples of selective breeding Darwin was able
to solidify and eventually proposed the idea of natural selection to explain
evolution. Artificial selection and its success was another source of
explaining evolution because it shows how a collection of naturally occurring
mutations can affect the appearance of an organism, when striving towards a
certain trait. If mutations were not allowed to occur, then the organism
could not vary from others in its population and selection would be impossible.
Artificial
and natural selection may seem very similar but there is one very important
difference to note. Natural selection is based on the fact that in nature, not
directly influenced by humans, individuals with certain inherited traits will
have a higher fitness level. This means that this individual will survive
longer to produce more viable offspring than its counterpart. Nature is the one
that “chooses” which variation to favor. Artificial selection, on the other
hand, is directly influenced by humans. Farmers have been performing a form of
artificial selection before they even really knew what they were doing. For example, a dairy farmer, he has many
dairy cows but he notices that one in particular produces twice as much milk
than his other cows. He would choose this dairy cow to mate, in hopes that she
will give him a calf that produces the same high rate of milk as its mother.
The same would happen with produce. The farmer notices that this stalk of corn
is sweeter than the rest of his corn; next season he would use that corn’s
seeds to plant with. Which would produce more stalks of sweeter corn.
Artificial selection has been used for many years, creating a better lifestyle in many cases. Some cases of artificial selection are solely for aesthetic purposes, while others are for more practical purposes. The following link shows two good examples of artificial selection through the use of pictures: http://evolution.berkeley.edu/evolibrary/search/imagedetail.php?id=382&topic_id=&keywords=
This is a great link from an AP Biology website if you can get past the strange computer, monotone voices: http://www.youtube.com/watch?v=R19zY1kkuSY
In Dr.Ryder's molecular genetics class we watched a movie called Gattaca. I don't know if you've seen the movie, but it was set in the future and dealt with artificial selection in humans. In the movie the main character had to steal another person's identity, who was genetically chosen, in order to get his job. Society pretty much only wanted genetically selected individuals. This movie was set in the future and I hope nothing like that would happen, but my point is do you think that there are times when they go too far in artificial selection? Maybe not as extreme as Gattaca but still sometimes people have a tendency to go too far.
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