Showing 1 - 10 of 61
We show that the problem of existence of a mitochondrial Eve can be understood as an application of the Galton–Watson process and presents interesting analogies with critical phenomena in Statistical Mechanics. In the approximation of small survival probability, and assuming limited progeny,...
Persistent link: https://www.econbiz.de/10011062948
We study the phenomenon of internal avalanching within the context of recently proposed “Tetris” lattice models for granular media. We consider a packing of particles subjected to two different dynamics. In the first case, we arrest the system at different instances during an “aging”...
Persistent link: https://www.econbiz.de/10011063008
We study the role of the noise in the dynamics of two competing species. We consider generalized Lotka–Volterra equations in the presence of a multiplicative noise, which models the interaction between the species and the environment. The interaction parameter between the species is a random...
Persistent link: https://www.econbiz.de/10010871988
The haploid–diploid cycle where, under unfavorable conditions the population becomes diploid, is modeled by a Monte-Carlo method in the framework of the Jan–Stauffer–Moseley hypothesis. Diploidy and sex may have first arisen as a way to escape death, when a simple unicellular individual is...
Persistent link: https://www.econbiz.de/10010872040
A family of evolution equations describing a power-law nonlinear diffusion process coupled with a local Verhulst-like growth dynamics, and incorporating a global regulation mechanism, is considered. These equations admit an interpretation in terms of population dynamics, and are related to the...
Persistent link: https://www.econbiz.de/10010872227
The transient dynamics of interacting biological species extracted from two ecosystems is investigated. We model the environment interaction by a multiplicative noise and the temperature oscillations by a periodic forcing. We find noise-induced effects such as enhanced temporal oscillations,...
Persistent link: https://www.econbiz.de/10010872388
In order to understand how a heterogeneous landscape affects a predator–prey system, a spatially explicit lattice model consisting of predators, prey, grass, and landscape was constructed. The predators and preys randomly move on the lattice space and the grass grows in its neighboring site...
Persistent link: https://www.econbiz.de/10010872552
We consider a monoparametric family of reaction–diffusion equations endowed with both a nonlinear diffusion term and a nonlinear reaction one that possess exact time-dependent particular solutions of the Tsallis’ maximum entropy (MaxEnt) form. The evolution of these solutions is governed by...
Persistent link: https://www.econbiz.de/10010873481
A neoclassical theory is proposed for the growth of populations in a spatially homogeneous environment. The proposed theory derives from first principles while extending and unifying the existing theories by addressing all the cases, where the existing theories fall short in recovering...
Persistent link: https://www.econbiz.de/10010873541
Starting from the well-known field theory for directed percolation (DP), we describe an evolving population, near extinction, in an environment with its own nontrivial spatio-temporal dynamics. Here, we consider the special case where the environment follows a simple relaxational (Model A)...
Persistent link: https://www.econbiz.de/10010873852