Size dimorphism was calcuated as the log-ratio of male snout-to-vent
length to female snout-to-vent length. (males are larger). In this example, we tested three models of evolution: Brownian
motion, Ornstein-Uhlenbeck with one global optimum, and
Ornstein-Uhlenbeck with 7 optima (one for each ecomorph type plus an
additional one for an ``unknown'' type).
For the 7-optima model, we assigned each terminal branch to an
optimum according to the ecomorph type of the extant
species. Because we had no information to help guide hypotheses
about internal branches, we assigned internal branches to the
``unknown'' selective regime. The phylogeny of these species is
consistent with and adaptive radiation, with a burst of speciation
events early in the evolutionary history of this clade (see
phylogeny in Butler & King (2004) or execute the following commands:
data(anolis.ssd)
attach(anolis.ssd)
tree.plot(ancestor, time, species, OU.7)