Thanks, Liam! That was really helpful. But what would be an alternative to
estimate evolutionary rates in those cases? Simply the sigsq estimate under
a white noise model? (which I assume is simply the variance in the original
data?)
Karla
On Wed, Sep 23, 2020 at 10:23 PM Liam J. Revell wrote:
Hi Karla.
> I just wanted to make sure that the estimate of sigma^2 in a BM model
> in fitContinuous is a meaningful measure of the rate of evolution of
> the trait even if its phylogenetic signal is low.
I would say that the answer to this question (if it were posed as one)
is 'no.' Another
Dear All,
Thanks for your fantastic feedback. Just a bit more background: I'm
interested both in the phylogenetic signal and the evolutionary rate. I
just wanted to make sure that the estimate of sigma^2 in a BM model in
fitContinuous is a meaningful measure of the rate of evolution of the trait
Carla, I can also suggest looking at some of the papers on this, such as:
Blomberg, S. P., T. Garland, Jr., and A. R. Ives. 2003. Testing for
phylogenetic signal in comparative data: behavioral traits are more labile.
Evolution 57:717–745.
Ives, A. R., P. E. Midford, and T. Garland, Jr. 2007.
Dear Karla.
What do you want to use fitContinuous to do?
fitContinuous fits multiple models, some of which will result in low
values of lambda in a test of phylogenetic signal. In fact, this is
really the main point of fitContinuous: to compare alternative models
for trait evolution. If you
Dear friends,
I guess this is as much a philosophical question as it is methodological. I
want to estimate the rate of evolution of a trait (e.g. using the
fitContinuous function), but the trait has low phylogenetic signal (e.g.
lambda close to 0). Does it make sense to use fitContinuous on a
