%0 Generic %1 lambert2010speciesabundance %A Lambert, Amaury %D 2010 %K Fishers_log_series branching_processes ewens_sampling_formula species_abundance_distribution %T Species abundance distributions in neutral models with immigration or mutation and general lifetimes %U http://arxiv.org/abs/1009.0118 %X We consider a general, neutral, dynamical model of biodiversity. Individuals have i.i.d. lifetime durations, which are not necessarily exponentially distributed, and each individual gives birth independently at constant rate łambda. We assume that types are clonally inherited. We consider two classes of speciation models in this setting. In the immigration model, new individuals of an entirely new species singly enter the population at constant rate \mu (e.g., from the mainland into the island). In the mutation model, each individual independently experiences point mutations in its germ line, at constant rate þeta. We are interested in the species abundance distribution, i.e., in the numbers, denoted I_n(k) in the immigration model and A_n(k) in the mutation model, of species represented by k individuals, k=1,2,...,n, when there are n individuals in the total population. In the immigration model, we prove that the numbers (I_t(k);k1) of species represented by k individuals at time t, are independent Poisson variables with parameters as in Fisher's log-series. When conditioning on the total size of the population to equal n, this results in species abundance distributions given by Ewens' sampling formula. In particular, I_n(k) converges as n\toto a Poisson r.v. with mean /k, where \gamma:=\mu/łambda. In the mutation model, as n\toınfty, we obtain the almost sure convergence of n^-1A_n(k) to a nonrandom explicit constant. In the case of a critical, linear birth--death process, this constant is given by Fisher's log-series, namely n^-1A_n(k) converges to \alpha^k/k, where :=łambda/(łambda+þeta). In both models, the abundances of the most abundant species are briefly discussed.

@misc{lambert2010speciesabundance, abstract = { We consider a general, neutral, dynamical model of biodiversity. Individuals have i.i.d. lifetime durations, which are not necessarily exponentially distributed, and each individual gives birth independently at constant rate \lambda. We assume that types are clonally inherited. We consider two classes of speciation models in this setting. In the immigration model, new individuals of an entirely new species singly enter the population at constant rate \mu (e.g., from the mainland into the island). In the mutation model, each individual independently experiences point mutations in its germ line, at constant rate \theta. We are interested in the species abundance distribution, i.e., in the numbers, denoted I_n(k) in the immigration model and A_n(k) in the mutation model, of species represented by k individuals, k=1,2,...,n, when there are n individuals in the total population. In the immigration model, we prove that the numbers (I_t(k);k\ge 1) of species represented by k individuals at time t, are independent Poisson variables with parameters as in Fisher's log-series. When conditioning on the total size of the population to equal n, this results in species abundance distributions given by Ewens' sampling formula. In particular, I_n(k) converges as n\to\infty to a Poisson r.v. with mean \gamma /k, where \gamma:=\mu/\lambda. In the mutation model, as n\to\infty, we obtain the almost sure convergence of n^{-1}A_n(k) to a nonrandom explicit constant. In the case of a critical, linear birth--death process, this constant is given by Fisher's log-series, namely n^{-1}A_n(k) converges to \alpha^{k}/k, where \alpha :=\lambda/(\lambda+\theta). In both models, the abundances of the most abundant species are briefly discussed. }, added-at = {2010-09-03T18:07:33.000+0200}, author = {Lambert, Amaury}, biburl = {https://www.bibsonomy.org/bibtex/28d118705f2d0008fd17081329e1737a5/peter.ralph}, description = {[1009.0118] Species abundance distributions in neutral models with immigration or mutation and general lifetimes}, interhash = {6a7c0dbf025536686d9c5b44c2c89308}, intrahash = {8d118705f2d0008fd17081329e1737a5}, keywords = {Fishers_log_series branching_processes ewens_sampling_formula species_abundance_distribution}, note = {cite arxiv:1009.0118 Comment: 16 pages, 4 figures. To appear in Journal of Mathematical Biology. The final publication is available at http://www.springerlink.com}, timestamp = {2010-09-03T18:07:33.000+0200}, title = {Species abundance distributions in neutral models with immigration or mutation and general lifetimes}, url = {http://arxiv.org/abs/1009.0118}, year = 2010 }