Hey everyone!
This week I'm going to discuss gene recycling and ask y'all a question pertaining to bioethics with a beautiful example given by Dr. Neil Shubin. This example should be familiar to all of us because it deals with Dr. Livingstone's intro bio module about Vitamin A and how important of a regulatory factor it is for early development. In the third chapter of his novel, Shubin talks about the preservation of genes from a shark to a mouse via the gene Sonic Hedgehog. Sonic Hedgehog is a gene present in every single limbed organism and is controlled by Vitamin A. Varying concentrations of Vit. A result in different part of limbs, such as a foot or a hand. Shubin tested the retention of the gene by taking mouse Sonic Hedgehog injecting it into a shark. The mouse gene ended up affecting the shark's limb development, proving that the mouse gene was the same gene that had simply been recycled from the shark's gene. Yeah, I know, this is mind blowing how strong of an example of common descent this is.
In the 50s and 60s, scientists discovered patches of cells in chicken embryos that, when flipped or sliced in half, would manipulate limb development. When born the chickens would have two sets of wings or have their wings mirrored (wings comprised of two tops of wings for one of the wings and vice a versa).
My question this week is: do you think, in general, it is ethical to create organisms that have a reduction in fitness because of experimental procedures done on them? I know that the information we learn from lab animals is invaluable, but would it not have been better if the researchers used, say, a house fly instead of a chicken to experiment on?
Hey Robby,
ReplyDeleteI understand where you are coming from. I am a huge animal lover and it really troubles me when animals with greater cognition and sense perception are used for experimentation. However, I am also a TA for the bilingual dissection course at Trinity and we work with cats and organs of pigs, sheep, cows, and goats. If you take Dr. Blystone's developmental biology class you will get to work with chick embryos and you may come to appreciate how much their developmental phases resemble our own and can also be translated into the in vitro development of other species.
The way I have reasoned it is as follows: It is necessary to understand the relevance of one system to another. When we can get by just using fruit flies and earth worms we should but when the application of our science affects human life, then we must recur to the organism that has a system that resembles our own. For example, we dissect and study cats to understand the human musculoskeletal system and pig lungs to understand human lungs and lobes.