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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

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

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
  1. 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.