Argument- How Important are Genes?
“Heredity, it turns out, is not as straightforward as we have
been taught. Parents do pass unaltered DNA to children, but they also pass on
additional instructional material-known as epigenetic material-which helps
guide how the genes will be expressed. While genes themselves do not change (by
and large) from generation to generation, the epigenetic instructions can
change. This means that we can impact our genetic legacy” (118). Knowing this,
are we in fact limited by our genetics? For example, are those of us who have
parents that did not play basketball competitively at a disadvantage because of
our lack of epigenetic instruction? Or are people whose parents did not attend
college at a disadvantage intellectually? How does this affect the GxE model? Find
evidence to support your answer and include references to Genetics (Chapter 20)
Unit and incorporate the biological themes of Evolution and Regulation in your
response.
Bowen Jin (bowenjin2004@yahoo.com)
I still do not believe that people are limited by our genetics. Shenk does say, “We can impact our genetic legacy… [but]…we don’t really have control over our environment that we have so long assumed.” (Shenk 118) This means that the parents can pass over epigenetic instructions on what genes should be expressed, but the environment can completely change those genes that had the epigenetic instructions. According to Campbell, “all organisms of a species contain the same genome” (Campbell 356), but different genes are expressed at different times in each organism, which makes each member of a species unique. Because of this statement, we all have the genome to become the next Michael Jordan or Yo Yo Ma. If introduced into the right environment in the critical period of humans, their genes can turn on or off to enable them to be great at what they are trying to accomplish. With this in mind, I don’t think it matters what your parents did because a person’s growth into who they are is dependent on the environment they were raised in. Knowing from personal experience, I have a cousin who plays baseball in the MLB for the Brewers. His parents never picked up a bat in their lives until he became old enough to take ground balls from them as a child. Because they got him into baseball at the age of 3, his genes expressed themselves in a way that would enable him to play better at baseball because the environment he grew up around was all about baseball. What made him different from other kids who grew up at a young age playing sports was that he also developed that mindset to always find problems in what he was doing to get better at baseball by fixing those critiques. How many stories have you heard of when a professional athlete has a child and the world expects them to follow in their parents footsteps. These kids may have grown up in the environment that promoted them to be good at the same sport their parents played in, but most of these kids don’t have the same drive to excel which ends up becoming their downfall to sports. When taking a look at the theme of evolution, the main idea is that organisms get mutations in their original genes that enable them to cope with the environment better or worse. If those genes were worse for the organism, the organism wouldn’t live long enough to reproduce and pass along the new epigenetic instructions to create that new trait. But, if the new trait promoted the chances of survival of that organism, then it will live long enough to reproduce and have offspring with that new trait. Because of evolution, we humans, have the same genomes and basic traits because those traits enabled our ancestors to survive long enough to pass their genetic make up to us through reproduction. With this in mind, we all have the same genome which supports that theory of the environment impacting which genes are turned off and on.
ReplyDeletehttp://www.horizonpress.com/cimb/v/v5/05.pdf
Eric Duresa (eduresa11@gmail.com)
I don’t altogether believe that Eric is correct here because I don’t believe that everyone has the chance to become the next Michael Jordan or Mozart. Yes it’s true that genes are not everything, but Shenk here does not propose that genes do NOT play an important role. Yes Mendelian genetics that we learned is definitely missing this connection between genotype and phenotype. What we learned were basic crosses of genes and that dominant and recessive alleles always eventually yielded a certain phenotype. What we did not learn is something known as quantitative genetics which acknowledges that certain measurable phenotypes such as height are dependent on the environment and do not follow Mendelian genetics.
ReplyDeleteHowever, I think it is still evident that our genes are truly a result of environment acting with evolution. Just tracking developments in different races, it can be strikingly clear of the environments effects and also of the natural selection involved. In particular with the Chinese people, education plays such an important role for them. Just hearing stories from my grandparents and my parents I know that the reason why they worked so hard in school and valued education so much was because it was the only way to survive. They had no time to do other things, sure there were occasional opportunities to relax and play, but everyone knew that you had to be the top to get accepted into universities. And only by getting into universities would you have a chance to perhaps move to America and further your education. These environmental pressures created an effect on the Chinese culture and so today we commonly associate Chinese people with intelligence. It’s because of this evolutionary process that Chinese people truly believed that education was the key to survival which led to changes in the genome.
So I do believe that genes still hold a high importance. I believe that because of evolutionary trends, that Chinese people will still have an edge in intellects. That is not to say that all Chinese people will become smart, of course gene interaction with environment as mentioned by Shenk is crucial. If a Chinese person (like my sister) spends a large part of her childhood brainlessly watching TV, then it’s possible that she may not have as great as an intellectual ability as she could. And yet, despite this being an environmental effect studies show that television viewing is actually moderately heritable.
http://en.wikipedia.org/wiki/Quantitative_genetics
http://www.rsc.org/chemistryworld/Issues/2005/August/china.asp
http://en.wikipedia.org/wiki/Gene-environment_correlation
kevin.liuxu@gmail.com
Kevin Xu