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Fig. 3 | BMC Evolutionary Biology

Fig. 3

From: Binary-state speciation and extinction method is conditionally robust to realistic violations of its assumptions

Fig. 3

Graphical depiction of speciation and extinction simulation. The blue line represents λ, and the red line represents μ (see Table 5). a λ and μ begin high, then decay exponentially through time, with the slower rate of decay in μ eventually leading to extinction outpacing λ. b λ begins high and decays exponentially, while μ remains constant. c λ begins high and decays, while μ begins low and increases. λ is scaled to 1 and μ to 0.5, representing that our simulations had an initial μ rate half that of λ. For trials in which the λ1 was greater than λ0, the multiplier for the derived state was in addition to that shown here; thus, λ1 began at 1.05 or 1.33 in these simulations, rather than 1. Time is scaled such that one unit represents approximately the amount of time necessary for the two rates to reach equal levels; before one time unit has passed, a clade is still diversifying, but afterwards, it is declining. For each set of state parameters, we ran 100 trials with each that ending at time t = 0.25, 0.5, 0.75, 1, 1.5, and 2. In real-world taxa, the exact length of time that one unit corresponds to, as well as the relative decay constants, varies among groups [10]

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