Figure 1.

Two examples of full (extant and extinct taxa) phylogenetic trees that contain 20 taxa at time t = 0 and have similar root ages. The first tree has been affected by a MEE that is defined under the “single‐pulse” scenario, and the second tree has been affected by a MEE, defined under the “time‐slice” scenario. Within these scenarios speciation rate, λ is assumed to be unchanged. In the “single‐pulse” scenario, the MEE is caused by a significant percentage of species being simultaneously and instantaneously removed from the tree, at a specified time. In the “time‐slice” scenario, the MEE is defined as a significant increase in the extinction rate, μ for a specific period of time, where the turnover or background extinction rate, ε = $\frac{\mu }{\lambda }$ > 1, followed with a decrease in μ that results in a return to ε < 1. In the two trees, the “pre‐MEE" μ is equal to “post‐MEE" μ but this is not necessary.