Thursday, December 28, 2006

Molecular biology: A science of exceptions?

Humans function as well as we do because we are adept at identifying patterns. Without this ability, we would be lost trying to understand such a complicated world. When it comes to understanding ourselves and our biology, then, we assume that patterns exist, and in our search we have found them: we have uncovered many "rules" (take, for instance, the central dogma of molecular biology) from which we have learned a tremendous amount.

But it seems that as time passes, we also find more and more exceptions to our "rules." Last year, French scientists found that RNA, not just DNA, can pass genetic information from generation-to-generation, contradicting (or at least not conforming to) Mendel's laws. Each day we learn more about the significance of epigenetics, the heritable effects that come not from the sequence of genes but from other characteristics and effects, including environmental ones. And finally, just last week, scientists uncovered that "silent" gene mutations, so-called because they do not affect the sequence of amino acids in a protein and thus were thought to have no effect, actually do have a significant effect on the performance of a protein.

Certainly it's the exceptions that we hear about, but I can't help but wonder if, in the future, we will find that biology presents us with more exceptions than conformers to the rules we think we have found.


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