Selfish Genes Turn Cooperative
Nature1 has reported evidence that transposons help to regulate gene expression. Transposons are genetic material that insert themselves into the DNA of a host, and were thought to represent “selfish genes” that only had their own propagation in mind, “without regard for the consequences.” Some new studies on the L1 retrotransposon, which makes up about 17% of the human genome (mainly within non-coding introns), have shown, however, that they may do us some good.
The studies “suggest that the insertion of L1 elements into introns can also diminish cellular gene expression in a graded fashion,” the News and Views piece says. “In the words of Han, Szak and Boeke, such L1 insertions provide a ‘molecular rheostat’ with which to govern gene activity � and their bioinformatics analysis establishes that the mechanism is widely used.” (For more on the molecular rheostat concept, see 01/10/2003 headline). If the transposons were truly selfish, “responding individually to darwinian natural selection” “without regard for the consequences,” it has “long been a mystery” what keeps them “at bay.” If the new studies “unveil a major control mechanism,” part of the solution may be to recognize synergy instead of selfishness.
1Frederic Bushman, “Gene regulation: Selfish elements make a mark,” Nature 429, 253 – 255 (20 May 2004); doi:10.1038/429253b.
How can a gene be selfish? A gene has no concept of self. It couldn’t care if it propagated itself or not. The myth of selfish genes is a misleading anthropomorphism. Only people are selfish.
On the other hand, genes are not altruistic, either. The metaphors of rheostats, regulators and molecular machines imply intelligent design and programming. That is not an anthropomorphism, because machines are not personal. Consequently, one doesn’t have to demonstrate anything about the designer to see the evidence that a product was designed. But observing that the design works so well (i.e., your senses are working as you read this thanks to the regulation provided by transposons), it wouldn’t hurt to ponder the subject a little.