--- Wyrm <[EMAIL PROTECTED]> wrote: > [EMAIL PROTECTED] wrote: > [snip] > > One question that might help-- does anyone know > approximately how many generations it takes for a > beetle species to go from flight to flightless when > placed in an environment that is highly selective > against flight, for example?
I'm not sure if anyone has tried that - but if you are using molecular markers you can mutagenize beetles at a higher then natural rate by exposing them (or their eggs) to chemical mutagens... then given enough beetles you'll find one with a mutation that has no wings. Then you'd make a molecular profile of it, and breed it back into the regular beetle population (because you want to get rid of any other mutations it might have that are bad) and then you'd use your molecular profile to better define the set of genes involved in wings. This would take 2 maybe three generations - depending how fussy your profile is. Then you'd breed your cleaned up wingless beetle to other wingless beetles to get a population of wingless beetles. > Does that number even > come close to modeling a similar circumstances in > humans? How quickly would I have almost all 7-foot > humans if we only allowed seven-footers to reproduce > with each other, and nobody else? Is it 1-2 > generations, or 10, or more? I think probably only > 1-2, to be honest. Height is a multigene thing that is largely influenced by environment. Breeding only 7ft isn't going to change things in one or two generations. But if you know the profile of the trait (which for don't for height) it would only take a couple generations. If you are thinking a single gene (or even something that's a handful of genes).... coat colour, hair colour, eye colour (these are genetically well characterized traits... and relatively simple)... then you can change things very quickly. The time of ten generations has to do with developing the genetic profile of a trait. Once you now that profile and you now how it's passed the whole process is much much faster. The problem is that initially you need to cross and back cross to both find and characterize your trait and then you need about 3 crosses to actually stabilize a single gene cross. Each cross is a generation or so.... by generation I mean from collecting seed to collecting seed (not necessarily animal maturity in the case of mammals where our eggs/sperm are mature faster then our ability to breed does). If you are talking natural selection then all the info about when the beetles breed becomes relevant.... if you are actively choosing traits and forcing and controlling breeding then all those problems become non-issues. The difference is between the lab and the wild. Oh - and I should mention another problem.... the trait you see in a lab environment may not hold true in the non-lab environment - because the way things act in one situation may not work in another situation. (Which explains how people can be highly intelligent physicists but aren't intelligent at all when it comes to asking a girl on a date.) -Sue (Who seems to be missing some mail from the list) :) _______________________________________________ GurpsNet-L mailing list <[email protected]> http://mail.sjgames.com/mailman/listinfo/gurpsnet-l
