Table 1.

A summary of generalized linear-mixed model (GLMM) analysis examining the contributions of family and species random effects to the variance in PO activity. (Italicized numbers indicate the highest relative contribution to the overall variance per substrate.)

substrate	species (n = 22)		family (n = 11)		residual	s.d.
	variance	s.d.	variance	s.d.
tyramine	0.039	0.197	0.002	0.041	0.160	0.400
dopamine	0.023	0.151	0.152	0.390	0.084	0.291
l-DOPA	0.046	0.214	0.130	0.361	0.074	0.271
hydroquinone	0.032	0.179	0.052	0.228	0.065	0.254