Fig. 3.

Distribution of clade sizes in two regions (open and filled symbols) within which clades diversify independently with random speciation (λ) and extinction (μ) and a uniform distribution of clade origination times between 0 and 40 Ma. The Inset in each panel shows the cumulative distribution of clade ages. (A) λ = 0.09 Ma⁻¹, μ = 0.00 Ma⁻¹; (B) λ = 0.16 Ma⁻¹, μ = 0.10 Ma⁻¹; (C) λ = 0.41 Ma⁻¹, μ = 0.40 Ma⁻¹ (see SI Appendix, section S13, for model fits and simulated clade statistics).