Wednesday, August 23, 2006

The Sinister Gene

I will be posting a series of essays I wrote for my General Psychology class this last year (I pray you will find them more interesting then that sounds). The class was pathetic. One of the many pointless assigments was a weekly concept paper.

It was only the previous year (senior in high school) that I had developed a passion for writing along with the "writers high", which you really do have to experience to understand. However, coming into college at MHCC, and taking a lot of higher math and sciences along with general ed. classes, there were not very many outlets for me to be challenged in my writing. (This was before I discovered the wonderful world of blogging of course.)

Instead of just slopping together these concept papers to merely get by with an A, I decided to have fun with them. Geek, I know. Consequently, this meant I was putting in a lot more effort and doing a lot more work then was required to get an A.

So here's my brilliant idea - I figure I can get a few more miles out of these papers in that some of you reading this might receive some form of enjoyment from my overachieving nerdiness.

*Warning* They normally start out really slow and technical, then they get good (I like to think so at least).

The Sinister Gene
Genes are the biological units of heredity, passed down through generations, located on the chromosomes. Behavior genetics is the scientific study of the role of the inheritance of these genes in the behavior of an individual. The characteristics are broken down in to two types. The genotype is the specific genetic makeup of the individual, which may or may not be expressed in the observable phenotype. The phenotype is the observable characteristics produced by one’s genetic endowment.
Even further, these genetic makeups are broken down into three resulting effects. The dominant effect is if the genes received from the mother and father are paired, resulting in a particular characteristic being displayed. However, if a gene recieved from one parent is recessive, the characteristic will not show up unless the partner gene inherited from the other parent is also recessive. The third, being Polygenic transmission effect, is when a number of gene pairs combine their influences to create a single phenotypic trait.

Approximately 10% of the population is left-handed. But it isn’t with out a fight. The English word "sinister" comes from Latin root originally meaning "left" but then took on the meaning of “evil" or "unlucky”. Across all cultural boundaries, there have been a history of discrimination against left-handers. In England Left-handers were severely discriminated against during the 18th and 19th centuries, for being associated with mental disorders and criminal nature, and it was often "beaten out" of people. Even the adjective "left" means "improper," "out of accord." In some parts of China, some adults can still remember suffering for the "crime", with suitable traumatic punishments, of not learning to be right-handed in both primary and secondary schools. Even the word "ambidexterity" reflects the bias. Its intended meaning is, "skillful at both sides." However, since it keeps the Latin root "dext," which means "right," it ends up conveying the idea of being "right-handed at both sides."

While it is not known for sure if left-handedness is a genetic trait, there is strong evidence to support this. Statistically, the identical twin of a left-handed person has a 76% chance of being left-handed. This makes sense considering that an identical twin shares the same chromosomes from a single sperm and one egg. Historically, there are stories of left-handedness being an inherited trait. The Clan Kerr, of Scotland, built their castles with counter-clockwise staircases, so that a left-handed swordsman would be better able to defend it. Likewise, many members of the British royal family are left-handed. Genetic factors are usually used to explain this.

When looking at a genogram diagram of my own family from generation to generation, there seems to be an on going characteristic of being left handed in the last 3 generations, with myself being one of them. My great grandfather on my mother’s side was left handed. That trait passed on down to his son, my grandfather. From there it did no pass on to my mother, however, it did pass down to her brother, my uncle. My father’s side is a little less straightforward. No one of direct lineage to me, going down from my great grandfather on my father’s side was left handed. However, my father’s brother has five kids, two of whom are left handed. Also, my father’s sister has a son who is left handed. It appears as if the trait is dominant only in males coming down my mothers side, so in order for it to be passed on to me, through my mother, there must also be a genetic characteristic of left handedness on my father’s side as well, which it appears there might be in some form.

All things taken in to account, the genetic nature of being left handed is hard to trace. Even still in my grandfathers generation, being left handed was frowned upon, and in most cases they were forced to be right handed. So in the case of my family on my father’s side, it is not known whether there is a genetic trait that has been suppressed by the environment or not.
David Knepprath
February 24, 2006

1 comment:

Mirranda said...

Ha, yes! I derive great enjoyment from your overachieving nerdiness. I remember reading some of your other psychology papers, but I didn't get to read this one before. :)