My empirical work focuses
on the evolution of body
size and shape in mammals;
in particular, how similar
changes may arise repeatedly
within a lineage as modification
of the rates and/or timing
of growth and development.
Subjects of study have included
the multiple, parallel instances
of dwarfism in insular fossil
elephants, of gigantism in
island rodents, and of size
reduction in tropical squirrels.
We address related issues
in different organismal systems:
for example, the role of
heterochrony in the repeated
evolution of flightlessness
in island birds, or the evolutionary
modification of embryonic
development in the diversification
of a clade of snakes.
Conceptual work has concentrated
on examining the biological
basis of homology; explaining
how, for instance, gross
phenotypic traits may be
conserved despite changes
in the genetic and developmental
processes producing them.
