Artificial Selection: Leave well enough alone!

Artificial selection has resulted in plants that are more disease-resistant, cows that produce more milk, and racehorses that run faster. One must wonder what will come next. In the blog entry, answer the following question –under what circumstances should humans be artificially selecting plants or animals, if any?

So once upon a time, I was at the mall and went to PJ’s pet store to look at all the animals and decided to get a pet hamster! I saw such a wide variety of hamsters; the very common golden hamster, white, black, brown, fluffy and smooth. I thought that the idea of a black hamster was very strange, yet at the same time, interesting, I finally decided on a black Syrian hamster. Whenever someone would see him, they would
say
“I didn’t know hamsters came in black.”
So I decided to do a little research…

The many variations of the Syrian hamster originated from a single female and her litter of pups found in Northern Syria in April 1930. This female was used to establish a captive breeding program from which the first domestic hamsters were created. Syrian hamsters came in just one colour, golden brown, but through artificial selection have since developed a wide range of colours and patterns such as brown, white, black, blonde, banded, tortoiseshell, and calico. I couldn’t believe that my tiny little hamster was the product of many years of science and breeding.

After researching the origin of my hamster, I concluded that artificial selection was unnecessary, and that I wouldn’t care if my hamster was a different colour. Having a variety of hamster colours neither benefits or disadvantages me or my hamster, it’s just unnecessary.

What exactly is artificial selection?
Artificial selection, or selective breeding is the reproduction of individuals that have desirable traits. Two adults that possess a desired trait –such as two dogs that are small- are bred together and the next generation of dogs will be even smaller. If artificial selection is continued, the population will be small.

Many many years ago, the wolf was domesticated and became man’s best friend. The hundreds of different domestic dog breeds that are present today were created through artificial selection.

When I researched dog breeds I found that artificial selection in pets has disadvantages. Selective breeding can lead to selecting genetic defects. For example large breed dogs, such as Golden Retrievers, German Shepherds and Labradors are known to have a heritable condition called Canine Hip Dysplasia. Canine Hip Dysplasia is a very painful condition of abnormal formation in the hip socket which causes joint instability and sometimes arthritis. In the case of selective breeding within dogs, artificial selection demonstrates a disadvantage for the dog and owner.

Almost the entire farming industry from crops to livestock is based on the technology of artificial selection. Corn for example, didn’t exist until many many years ago. Before corn was in another form -teosinte- corn’s tinier and less tasty cousin. Artificial selection in agriculture is responsible for many modern day vegetables in addition to corn that we have come to know and love. Cabbage, broccoli, cauliflower, Brussels sprouts, collards and kale are have all originated from the same wild mustard plant.

The meats we eat are yet another product of artificial selection. In the 1950s, it took 84 days to raise a 5 lb chicken, however thanks to selective breeding, scientists have made it possible to for a chicken to grow more than its full size in only 45 days. By accelerating the chicken’s growth rate, farmers’ profit is increased, but at the same time, many health problems arise amongst the chickens. These types of chickens are called broiler chickens, they are bred to eat a lot and have low levels of activity for the sole purpose of tender meat production. Since they are putting on weight so rapidly, a broiler chicken’ bone growth is outpaced by the growth of their muscles and fat which leads to many leg disorders causing crippling lameness. These birds are growing so quickly that many of them cannot walk very far, let alone stand up.

a broiler chicken alongside a layer hen (a hen This boiler chicken is unable to support itself

raised to lay eggs) at same age of six weeks

At first I was against artificial selection because of the heritable deformities in pets and the abusive ways it is used in meat production. I thought that the only positive use for artificial selection was in crops knowing that it is how corn and many other vegetables came to be. However, there is one more downside to artificial selection. Artificial selection reduces the genetic diversity in the gene pools in selectively bred populations. Species need their genetic variation to resist a variety of diseases, but without this variation, populations are vulnerable and could be wiped out by a small change in environmental conditions.

In conclusion, there are both disadvantages and advantages to artificial selection. Just as a knife can be used for good intentions (such as slicing vegetables), it can just as easily be used for bad intentions (like stabbing someone with it), artificial selection is good with good intentions (like breeding cauliflower, broccoli, and cabbage from a mustard plant) and bad with bad intentions (like breeding chickens to grow in 45 days). Just as I have said in my previous blogs, humans are always striving towards perfection whether it is through designer babies or our other many advancements in technology. Artificial selection is another one of the many ways we have tried to alter nature to suit our preferences. When we try to perfect something, it is usually only “perfect” in our eyes and seldom does it benefit anyone else other than ourselves. To what extent are we willing to go to satisfy our desires? Is having a pure bred golden retriever worth your dog suffering from Canine Hip Dysplasia? Humans need to learn to leave well enough alone.

Works Cited

http://www.bbc.co.uk/dna/h2g2/A1097246

http://www.learner.org/courses/essential/life/session5/closer1.html

http://library.thinkquest.org/C0118084/Gene/Genetic_variation/artificialselection.htm

http://www.lycos.com/info/hamsters--golden-hamsters.html?page=2

http://evolution.berkeley.edu/evosite/lines/IVAartselection.shtml

http://animals.howstuffworks.com/pets/dog2.htm

http://www.chickenindustry.com/cfi/broilerindustryreport/selectivebreeding/

http://www.humanefood.ca/broilerchickens.html

http://www.dogtrainingpet.com/selective-breeding-can-sometimes-mean-selective-for-genetic-defects/

http://library.thinkquest.org/C004367/be3.shtml

http://www.aact.org.au/broiler_hens.htm