Friday, January 02, 2004

some other things
The wonderful Alan Davidson died last month. Grimes reflects formulaically on his tenure -- but he made me hungry. Like everywhere else, China is about to run out of water. Nature Biotechnology reviews Dangerous Liasons:
Ellstrand correctly highlights one characteristic that differentiates today's transgenes from most conventional domestication alleles: dominance. Traditional domestication genes are largely recessive, whereas commercialized transgenes have been universally dominant. Dominance will cause the effects of transgenes to be manifest even when heterozygous, as in progeny of first generation crosses between crops and wild plants. This can enable much more rapid spread of advantageous genes (e.g., herbicide- or pest-resistance genes in some environments), but should equally likely slow the spread of genes for domestication traits that lower fitness within wild populations. Conventionally bred traits are also more commonly part of multigenic systems (several unlinked genes, not one, give the new trait). This makes it more difficult for natural selection to operate on the new alleles.

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