DNA and Characteristics
Country: United States
Date: May 2007
How can you determine how the DNA bases figure the way we look
and our actions, for example, I have the gene that makes me run fast.
With so many discoveries of how some genes link to certain traits, many
people (erroneously) believe there is a single gene for each trait we have
(such as a gene to run fast). The link between DNA and traits is much more
complicated than that. Many traits aren't genetic at all. A boxer's crooked
nose is from fighting, not his DNA (probably). Other traits may be a
combination of genes and environment. Other traits we simply don't know.
A DNA molecule is very complex, and how its information gets 'transformed'
into a life form is even more complex. Certain sections of DNA (groups of
DNA bases, as you said) can be translated into proteins. Other sections do
not go into proteins. They might control how other sections of DNA are used,
or they might not be used at all. Only some of our DNA actually turns into
proteins. And, after the DNA is used, many changes can be made before the
protein is in its final useful form.
One protein can affect lots of different traits. They all work together as a
team. Imagine an American football team -- the quarterback might throw the
ball, hand off the ball, run with it himself, or on a trick play he might
catch it. He can also hold the ball for the kicker. Proteins are the same
way -- they can do lots of different things. And, there are hundreds of
thousands of proteins (not just 11 like the football team). So imagine all
the sportscasters of the world arguing about why a team of 100,000 players
won or lost a game -- that's kinda like scientists trying to figure out how
all our genes work.
For some traits, we have a good idea of which gene controls a trait. For
other traits, there is no single gene or protein than determines the trait.
It's a combination of many. Like with your example, there are many, many
traits that cause you to run fast, and only some of them are genetic. Your
nutrition, how much sleep you got, your general health, etc. are all
non-genetic factors that influence how fast you run.
Right now, we can look at a person's DNA and tell a few things, but we can't
tell if they'll be 'smart' or 'fast' or 'pretty'. And, this is a big ethical
dilemma too -- if we could predict all those things (or change them), would
it be right to do so?
I mentioned a lot of different issues related to this question. I hope these
are good starting points for you.
Genes (base pair sequences in DNA) code for the types and amounts of proteins
and enzymes synthesized by the cells of an organism. Proteins form part of the
structure of an organ or tissue and enzymes catalyze every chemical reaction
that occurr in a cell.
Ron Baker, Ph.D.
Click here to return to the Molecular Biology Archives
Update: June 2012