Table 5 Arion diversification tests using rate-constant (pure-birth, birth-death) and diversity-dependent diversification decoupled model (DDD), yule-2-rate and time-varying speciation and constant extinction (SPVAR).

From: Different diversity-dependent declines in speciation rate unbalances species richness in terrestrial slugs

Package

Function

IST

Model

λ 0 or r 0†

Extra parameters

μ 0

K

AIC

Δ AIC

DDD

dd_ML

yes

Birth-death (λ 0A, μ 0A)

0.189

 

0.000

Inf

31.562

11.41

DDD

dd_ML

yes

DDD ( r 0 A, K A)

0.586

 

‡

23.046

20.147

0.00

diversitree

make.bd.t

yes

yule2rate (r 0A, r 1A)

0.040

r 1 = 0.285

‡

‡

23.586

3.44

diversitree

make.bd.t

yes

SPVAR (r 0A, r 1A, kA)

0.046

k = −0.248

0.000

‡

24.278

4.13

  1. Bold  identifies the best-fit model. AIC’s and the difference in AIC’s with the best model (∆AIC) are shown. IST, incomplete sampling taxa; λ 0A, the initial speciation rate in Arion; μ 0A, the initial extinction rate in Arion; μ 0, extinction rate when applicable; KA, carrying capacity parameter of DDD model; r 0 (= λ 0 − μ0), initial net diversification rate for DDD, yule2rate andSPVAR models; r 1 = net diversification rate after the first shift at time t 1; k, parameter of the exponential change in speciation rate for the models SPVAR; † in this study μ0 is zero therefore r 0 is effectively equal to λ 0. ‡ the parameter in the model is fixed to zero.
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