Dear Florian,
following Ted's comment:
1) Is the data you are analyzing normally distributed? It is possible that you
detect significant signal with a very low K in datasets that deviate
substantially from normality. Note that under Brownian motion you'd expect
something like a normal
Dear Florian,
A K values of 0.041 is very small. It is hard for me to imagine that the
randomizaton test for the presence of phylogenetic signal (Blomberg et al.
2003), which is based on the MSE not K, is significant. I cannot vouch for
what those R packages are doing. I would suggest that you
Hello Florian.
I would agree that the value of K you have observed is very low. Since K
is a standardized variance ratio, this suggest that (controlling for the
phylogeny) most of the variance is partitioned within, rather than
between, clades.
That being said, on large trees even small
Dear Ted,
yes - I have a trait with K = 0.041. It differs significantly from random
expectation (p = 0.001, command phylosig, package phylosig and command
phylosignal, package picante). But it also differs from the Brownian motion
model (p = 0.001, simulated with brownie.lite and fastBM). I
Dear Ted,
yes. I have a trait with K = 0.041. According to randomization tests, K differs
from the random expectation (p= 0.001; test from Blomberg et al. 2003, computed
with 'phylosig' from the phylosig package) AND from the expectation under a
Brownian Motion model (also p=0.001; simulated
