FIGURE 6.

LTT plots (stars) of four bird phylogenies, selected from Phillimore & Price (2008) (see text for selection criteria) and the fits of the protracted birth model (gray) and the protracted birth–death model (black). The former is obtained through maximum likelihood, the latter by least squares (see text). We assumed that μ₂ = μ₁ and λ₃ = λ₁, so the fitted parameters are λ₁, λ₂, and μ₁.