Disparity in the timing of vertebrate diversification events between the northern and southern hemispheres

Table 2 Effects of hemisphere (northern versus southern) and thermoregulatory strategy (endotherm versus ectotherm) on intraspecific estimates of species ages from temperate-regions across the globe

Variable	Likelihood ratio (D)	P
(a) Complete dataset
Hemisphere	D = 14.1	< 0.001
Thermoregulatory strategy	D = 16.1	< 0.0001
Hemisphere * Thermoregulatory strategy	D = 0.844	0.358
(b) High-latitude species
Hemisphere	D = 13.2	< 0.001
Thermoregulatory strategy	D = 7.35	0.00670
Hemisphere * Thermoregulatory strategy	D = 0.521	0.471
(c) Low-latitude species
Hemisphere	D = 8.98	0.00270
Thermoregulatory strategy	D = 60.7	< 0.0001
Hemisphere * Thermoregulatory strategy	D = 0.652	0.419

Results are shown for the entire dataset (a), for the subset of species that are distributed above 40° N or S (b), and for the subset of species that are distributed between the tropics and 40° N or S (c). Likelihood ratio tests were conducted between nested models that included and excluded each variable; however, main effects were tested for significance only after excluding the interaction term.

ISSN: 2730-7182