Table 1.

Results of PGLS analyses individually testing relationships between 18 traits and diversification rates of animal phyla. Brief descriptions of each trait and regression results are shown. The results are for Tree 2 and the intermediate relative extinction fraction (epsilon=0.5). Results for other trees and epsilon values are in Supplementary File S4. Correlation coefficients (r²) and P-values are shown with significant values boldfaced.

Trait	r 2	P
Proportion of species exhibiting sexual reproduction	0.03	0.354
Presence or absence of cephalization	0.06	0.209
Presence or absence of a circulatory system	0.04	0.323
Presence or absence of coelom	0.01	0.672
Presence of a digestive system with two openings	0.09	0.111
Proportion of dioecious species	0.17	0.027
Presence or absence of an excretory organ	0.12	0.072
Presence or absence of legs	0.08	0.153
Median biovolume in mm3 (ln transformed)	0.02	0.516
Proportion of species undergoing metamorphosis	0.04	0.300
Proportion of non-marine species	0.37	0.001
Proportion of parasitic species	0.26	0.005
Presence or absence of segmentation	0.09	0.123
Proportion of species that have a skeleton	0.14	0.047
Presence or absence of bilateral symmetry	0.06	0.214
Proportion of terrestrial species	0.27	0.005
Proportion of vagile species	0.01	0.597
Presence or absence of photoreceptors/eyes	0.38	<0.001