>This seems rather simplistic since simple polymorphisms between
> individuals of the same species probably would involve changes in more
>than 5 genes.
>Besides, I do not understand how such a number could be obtained
> without sequencing the entire genomes of both species. Believe it or
>not, there are still a few genes out there waiting to be discovered.
>
Apparently, these genes control the developmental program of the plant. At
least in the case of Monkeyflowers they say that most of the
morphological change is controlled by the 8 genes. The rest of the
morphological differences are in other genes. What the Monkeyflower
authors hinted at, was that one could now experimentally evolve a line of
descent from one species to another.
"For each trait we found at least one quantitative trait locus accountinf
for more than 25% of the phenotypic variance. This suggests that genes of
large effect can contribute to speciation." Nature Aug. 31, 1995, p. 762
"This finding suggests that the evolution of reproductive isolation may
involve genes of large effect and therefore that speciation may occur
rapidly." p. 765
"This hypothesis for the evolution of hummingbird pollination is testable
in part by introgressing the M. cardinalis allele at each major QTL into a
M.Lewisii genetic background (...) followed by assessment of pollinator
visitation and its fitness consequences in nature." p. 765
Experimental evolution from one species to another. In the future.
glenn
Foundation,Fall and Flood
http://members.gnn.com/GRMorton/dmd.htm