Monday, November 9, 2009

46 Chromosomes and One Fat Toe

In a former life I loved science. I majored in zoology, with a human biology emphasis. I came into the major my junior year of college. I'd been a chemical engineering major who burned out, turned to anthropology for solace and interest, but returned to science because I'm just not the kind of person who enjoys an easy A. Give me a struggle for a B and I'm much happier. My core classes taught me many things. In my former life I could assay fruit flies to test for genetic variations. Frozen flies happen to be just as disgusting as live flies. I could isolate caffeine out of a cup of tea. It's white by the way, and looks just like some other drugs that are white powders. I could name all the bones in the human body. I could open a Tupperware full of embalmed male genitalia and not vomit. I used to be able to explain the Krebs Cycle. Those days are gone. It has been years since I've been in a lab. Over a half decade since anyone has called upon my scientific knowledge. What has never left me though was a great appreciation for the human body and all the marvels that go into one single being. Take a chromosome for example. That single piece of DNA can be upwards of a million nucleotides long, and in the variation of those nucleotides holds all the information necessary to make all the difference in the world. It is what makes me, me and not a chimpanzee or a sheep. It is what makes me, me and not my neighbor Julianne. The normal human gamete holds 23. When two gametes meet and fertilization occurs a 46 chromosome zygote is born. That cell contains all the information needed to create a human being. It is fantastical. Nothing we've created on this earth nears this in simplicity or complexity. These gametes are created by a system of meiosis. It takes one cell, doubles the genetic material, and then splits it twice so that four daughter cells with half the genetic material are created, giving rise to genetic variations in future generations. Take two individuals gametes together and you have mounds of possibilities . It makes it fun when children are born, trying to pick out the pieces of them, guessing, where they got their nose, where they got their eyes. Some traits are recessive and so they are a big surprise to see. Some traits aren't. Dr. J and I both have very bushy eyebrows. No surprise all three of kids do as well. I have brown eyes, and Dr. J has blue. Thanks to a recessive gene from my mother we have two with blue and one with brown. Today when I was nursing my daughter Peach I noticed she has an incredibly fat big toe. This is not the case for either of her parents but my sister has a fat toe as well so I'm guessing somewhere in my gamete there must be a fat toe gene :)

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