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Table 1 Effects of hemisphere of origin (northern versus southern) and taxonomic class (Mammalia, Aves, Amphibia, Reptilia, Actinopterygii) 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 = 14.2 < 0.001
Taxonomic class D = 28.8 < 0.0001
Hemisphere * Taxonomic class D = 1.72 0.786
(b) High-latitude species   
Hemisphere D = 10.5 0.00120
Taxonomic class D = 15.0 0.00190
Hemisphere * Taxonomic class D = 2.14 0.544
(c) Low-latitude species   
Hemisphere D = 9.62 0.00190
Taxonomic class D = 63.5 < 0.0001
Hemisphere * Taxonomic class D = 7.17 0.127
  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.