Dear all, I'm seeking help with modularity tests using the EMMLi package in R. I have developmental data for different species of mammals, and my goal was to group specimens in each species by age classes (e.g., neonate, juvenile, adult based on tooth eruption) and then test different hypotheses of cranial modularity following Goswami & Finarelli 2016 EMMLi: A maximum likelihood approach to the analysis of modularity. Evolution 70:1622–1637. Some of those groupings are rather small, <10 individuals.
The first step is to generate a correlation matrix from the 3D array of landmark coordinates (Y), but when I do I get the message Warning message: In dotcorr(Y) : CVM has negative eigenvalue -1.1286357464565e-15 Will this will cause problems for the EMMLi model test, or I can I ignore it and move on? Also, does anyone have thoughts of the minimum number of samples one can use to compare modularity hypotheses? In Goswami & Finarelli, they show that reducing the dataset down to 10 individuals from 48 still performs very well, but is there a true minimum? For example could I take the 3 largest individuals from each species for the test? Thanks for any advice, Christy -- MORPHMET may be accessed via its webpage at http://www.morphometrics.org --- You received this message because you are subscribed to the Google Groups "MORPHMET" group. To unsubscribe from this group and stop receiving emails from it, send an email to morphmet+unsubscr...@morphometrics.org.