Thursday, February 4, 2010

THAT DOG LOOKS LIKE A WOLF!


Question: 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?


----------------------------------------------------------
We live in a very materialistic world
, would you agree? Personally, I cannot shake my head at this statement, verifying that this statement is not at all, in any way true - I'd simply be lying. The other day I was conversing with my parents (such a miracle that was) brainstorming about what type of family dog we'd get. As the conversation grew, we found ourselves settling on a mix breed of a Shih Tzu and Pomeranian. It is a pure coincidence now that I find myself discussing a topic based on humans artificially selecting plants or animals for desired results.

Artificial selection can be defined as intentional breeding in hopes for certain traits/genes. Artificial selection can be achieved by purposefully altering the gene pool of a species. This is the opposite of natural breeding. In relation, we could say that artificial breeding is natural breeding with human interference. In reality, although humans may have the best interests at hand, things such as the life span and organ systems of the organisms are directly effected.

To start off, I must comment on how this topic and the previous topic are very similar with a slight variation in their contexts. In the previous bio blog we observed and discussed how it was morally wrong to "design" unborn babies to our (human) liking. With this topic, I will be observing and discussing how "scientifically" or "experimentally" or "morally" wrong it is to artificially select plants and animals to our (human) likings. See the similarities? See the differences?

The origins of artificial selection began with Charles Darwin (12 February 1809 – 19 April 1882). Charles Darwin proposed the scientific theory that the branching pattern of evolution resulted from a process called natural selection. From his research, scientists were able to elaborate on his results and manipulate the genes in an organism. As technology continued to grow (as if it ever stops), we now find ourselves being able to personally pick and choose exactly which gene we would like to have in an organism. Who was I to think that shopping online was such a milestone?

Accomplishing artificial selection can only occur with exact precision and ensured totality of achieving a goal. Scientists observe a plant or animal, distinguishing a gene that would like to be desired. Subsequently, the plant or animal is then bred with another of its kind with the same exact gene. In doing this, the ratio of the F1 phenotype will be more probable of being what is aspired for. The cycle can be repeated multiple times until the possibility of the possible offspring phenotypes is 100% exactly what is desired.


Most livestock, including dogs, cats, goats, pigs, cattle, sheep, guinea pigs, horses, and geese were domesticated more than 5 000 years ago. Domestication can be defined as an act upon humans reflecting a change in the system, more specifically plants and animals. Experts have agreed that one of the first mammalian species to become domesticated are dogs, which can been seen accurate through comparing the organism to its gray wolf (Canis lupus) ancestors. One major reason in which dogs are artificially selected when bred is to eliminate aggressive looking traits. Dairy cattle are another example of artificial selective organisms. Dairy cattle are bred in hopes of producing more milk, unfortunately some cattle suffer from problematic infections and fertility complications, due to the altering of their gene pool. Persian cats are bred in hopes of a more 'flat-faced' feature, this change has led to respiratory and digestion complications. All of these prime examples of organisms have gone through artificial selection solely for cosmetically reasons and not at all because of health related impediments.

It is clear that artificial selection has many negative side effects, through examination of specific organisms. This type of selection removes variation in a population, leading to selectively bred organisms susceptible to diseases or changes in the environment that would not cause such a complication for a natural bred population. Inbreeding can be defined as a genetic term that refers to reproduction as a result of the mating of two animals which are genetically related to each other. Inbreeding can cause a definite predicament, more specifically if both organisms contain recessive alleles, leading to deformities or even death. In dogs, inbreeding has resulted in breeds that have health issues ranging from decreased life span to hip dysplasia.



Artificial selection not only occurs in animals, but in plants as well. Corn is a well-known example of selective breeding, whom without would be more commonly known as a teosinte. In the picture, the works of artificial selection can receive its 'acknowledgments'. The image on the left is a teosinte, and on the right is its modern descendant, corn. I know I wouldn't want to be the one eating that teosinte! Cabbage, broccoli, cauliflower, brussels sprouts, collards, and kale are all members of the same species, Brassica oleracea. All of these well-known vegetables would not be known today without selective breeding.

In researching and learning about this topic, which of what I was stranger to preceding this biology blog, I was able to gather many new insights. In knowing that selective breeding has had SUCH an impact on the world, and even so my life, I cannot 'condemn' this idea to death. Would the world not be very different without selective breeding. I learned through my research that selective bred offspring do have several harmful side effects, effecting not only that organism, but can end up hurting the whole ecosystem in the end. In my opinion, everything can have a possible 'pros and cons' list, the question that still stands is whether or not it is worth the chance. Personally, I find myself optimistic about this topic. I DO believe that organisms can continue to evolve with the help of human interferences to invent new hybrids and who knows what else! With this said, I do believe that there must a 'drawing line' between what is acceptable and what should be looked down upon. Selective breeding for pure cosmetic use, for example, should not be permitted. Why risk the health of an organism just so that they will be more attractive. (Guess I should be saying the same thing to all those getting plastic surgery *cough .. Heidi Montag ) With all this said, I'll end this in commenting that 'it's not the outside that matter's, it's all that is inside'

Works Cited List

http://www.learner.org/courses/essential/life/session5/closer1.html
http://www.learner.org/courses/essential/life/session5/closer1.html
http://en.wikipedia.org/wiki/Artificial_selection
http://www.biology-online.org/2/12_selective_breeding.htm

BLOGS COMMENTED ON;

Christina Chong

Tammy Nguyen