search for: dimorph

Hello! I am working on a manuscript on sexual dimorphism in an aquatic invertebrate, where we have estimated sexual dimorphism (SD) for 7 different traits in four populations (a total of 28 SD-estimates). We have used the following formula for estimating SD: 100 * (mean male trait value - mean female trait value)/overall trait mean). Then, we have us...

Hello people I am doing some thinking about how to analyse data on dimorphic animals - where different individuals of the same species have rather different morphology. An example of this is that some male beetles have large horns and small wings, and rely on beating the other guys up to get access to mates, whereas others have smaller horns and larger wings, an...

Dear all, Does anyone know if the mixture analysis (i.e : sexual dimorphism, age group,…) can be done with R software ? Thanks for your help Dan --------------------------------- [[alternative HTML version deleted]]

I'm trying to perform ANCOVAs in R 1.14, on a Mac OS X, but I can't figure out what I am doing wrong. Essentially, I'm testing whether a number of quantitative dental measurements (the response variables in each ANCOVA) show sexual dimorphism (the sexes are the groups) independently of the animal's size (the concomitant variable). I have attached a 13-column matrix as a data frame (so far, so good). But then I tried to do this: >model<-lm(ln2~sex*ln1) or this: >model<-lm(ln2~sex+ln1) and got this: Warning messa...

...neralized non-linear least squares function within the nlme library, to study evolutionary questions where correlations between traits at the species level are non-independent because of the evolutionary relatedness of the species. Specifically, they're using a non-linear function (log(sexual dimorphism) ~ log(a + b*variation in mating opportunities), an exponential spatial correlation function that depends on the phylogenetic distance between species [I hacked the library a little bit to allow one to specify a distance matrix directly, rather than specifying spatial positions], and a weight...