[R-sig-ME] interpreting random effects

[Keith Larson]

I have have measured the trait frequency for a "mountain" associated
allele across a number of sites and years. In my (glmer) model I have
summarized the allele frequency by site and year as the dependent
(binomial) variable and specified site and year as random effects. The
fixed effects are latitude, longitude, altitude, and
latitude|longitude. When I run the model and then drop and update each
random effect separately to see if they are important to the model,
site appears to be significant and year does not. Two questions:

1. Can I re-summarize my dependent variable for by site rather than
site and year?

2. Given that we did not sample each site the same number of times
(years) and have different numbers of samples at each site (and year),
should I standardize my dependent variable?

Thanks,
Keith Larson, PhD Student
Evolutionary Ecology, Lund University