testing for different rates of continuous trait evolution - r8s and Brownie

O'Meara, B.C., C. Ané, M.J. Sanderson, and P.C. Wainwright. 2006. Testing for different rates of continuous trait evolution using likelihood. Evolution 60(5): 922-933.
http://www.brianomeara.info/publications

Rates of phenotypic evolution have changed throughout the history of life, producing variation in levels
of morphological, functional, and ecological diversity among groups. Testing for the presence of these rate shifts is
a key component of evaluating hypotheses about what causes them. In this paper, general predictions regarding changes
in phenotypic diversity as a function of evolutionary history and rates are developed, and tests are derived to evaluate
rate changes. Simulations show that these tests are more powerful than existing tests using standardized contrasts.
The new approaches are distributed in an application called Brownie and in r8s