1 Citation 557 Views 165 Downloads
Haplotype phylogenies based on DNA sequence data are increasingly being
used to test traditional species-level taxonomies based on morphology.
However, few studies have critically compared species limits based on
morphological and DNA data, and the methods used to delimit species using
either type of data are only rarely explained. In this paper, we review
three approaches for species delimitation (tree-based with DNA data and
tree-based and character-based with morphological data) and propose
explicit protocols for each. We then compare species limits inferred from
these approaches, using morphological and mtDNA data for the Yarrow's
spiny lizard (Sceloporus jarrovii), a traditionally polytypic species from
the southwestern United States and Mexico. All three approaches support
division of S. jarrovii into five species, but only two species are the
same among the three approaches. We find the greatest support for the five
species that are delimited based on mtDNA data, and we argue that mtDNA
data may have important (and previously unappreciated) advantages for
species delimitation. Because different data and approaches can disagree
so extensively, our results demonstrate that the methodology of species
delimitation is a critical issue in systematics.
557 views reported since publication in 2009.