Steve Schaffner
Posts: 13 Joined: June 2009

Quote (Bob O'H @ June 19 2009,12:02)  I haven't looked at the code, but if we assuming a constant population size and discrete generations, then (ignoring recombination and mutation), the way to model this is to assume that each parent has a fitness s_{i}. The offspring are then drawn from a multinomial distribution with probability for the ith parent being
s_{i}/sum(s_{i})
(this would reduce to a binomial distribution if there were only 2 parents). The multinomial sampling is genetic drift.

Yes, I've written a program for that kind of model, except that I imposed selection in the differential survival of the offspring. Including options for truncation selection and a few other things, it amounted to all of 158 lines, including comments, white space and the multinomial routine.
Quote  You can treat log(s_{i}) as you would any standard trait: it's additive, so you can add the genetic and environmental effects.

I haven't thought about this before. Does adding environmental effects do anything more than reduce the effective selection coefficient?
