pantoum's Diaryland Diary ----------------------------------------------------------------------------------------- BYPASSING HEREDITY Maybe I should call this entry }Farewell Evolution?, or, Mendel, We Hardly Knew Thee} or something instead but.... regardless of what we call it, I wish I remembered more from my genetics and biology coursework because this discovery of a little mustard plant that fixed its flawed gene is utterly fascinating—as is the fact that the genome isn't even made of DNA. So the little self-improvement plant that could—let's call it Mildred just for fun, shall we? Yes, Mildred the Mustard Plant, that's catchy. So Mildred inherited a defective gene from Mom and Pops, yet somehow reverted to normal, improved on heredity. Now it's true that scientists have altered genes for a while now, but they need a template, a corrected copy of the gene, for mutation purposes. Mildred's actual gene changed. No template. No fog and mirrors. Changed. How did she correct the actual sequence of DNA units in her own gene? Determine the flawless sequence? Could this ability to correct inherited defects apply across the board in nature, or is it limited to Mildred and her kin? And what has Mildred done to Mendel's laws of inheritance? For that matter, what does a handy backup system that allows organisms to fix themselves—or, as New York Times science writer Nicholas Wade so elegantly puts it, to generate novelty—do to the theory of evolution, to the assumption that it is mutations rather than backup systems that fix us? Wade made this observation: The finding could undercut a leading theory of why sex is necessary. Some biologists say sex is needed to discard the mutations, almost all of them bad, that steadily accumulate on the genome. People inherit half of their genes from each parent, which allows the half left on the cutting room floor to carry away many bad mutations. . . . The backup genome could be particularly useful for self-fertilizing plants . . . since it could help avoid the adverse effects of inbreeding. It might also operate in the curious organisms known as bdelloid rotifers that are renowned for not having had sex for millions of years, an abstinence that would be expected to seriously threaten their Darwinian fitness. If humans contain backup copies of correct genes, then I want to go back to whatever great-great whatever did not have schizophrenia and diabetes and bypass the usual mechanisms of heredity, since my odds of getting diabetes are really high. My odds of passing schizophrenia on to a child are incredibly high too, and I would like to correct that possibility in all of my family members. (And let's don't even talk about how much I won't let myself look at my numerous nieces and nephews and wonder which one of them will start showing signs of that shift into paranoid delusions.)
FINAL FACTOID: the mutated gene is known as a hothead gene ... and I just know there's a Hothead Paison joke in there somewhere! 3:49 p.m. - 2005-03-24 ----------------------------------------------------------------------------------------- |
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