| Comments |
P.1 right column bottom paragraph: "Second, molecular-based phylogenies cover many taxa and environments, providing an appealing alternative to the fossil record’s shortcomings. A simple model of the observed increase in the number of species St in a phylogenetic clade over time, t, is St = S0 exp[(λ – μ) × t], where λ and μ are the speciation and extinction rates. In practice, λ and μ may vary in complex ways. Estimating the average diversification rate, λ – μ, requires only modest data." P.2 left column 3rd paragraph: "Third, data on net diversification, λ – μ, are widely available. Plants (primary source 23) have median diversification rates of 0.06 new species per species per million years, birds 0.15 (primary source 24), various chordates 0.2 (primary source 22), arthropods 0.17, (primary source 22), and mammals 0.07 (primary source 22). The rates for individual clades are only exceptionally >1. Valente et al. (ref 25) specifically looked for exceptionally high rates, finding them >1 for the genus Dianthus (carnations, Caryophyllaceae), Andean Lupinus (lupins, Fabaceae), Zosterops (white-eyes, Zosteropidae), and cichlids in East African lakes." |