Density-Dependence as a Size-Independent Regulatory Mechanism

Details Density-Dependence as a Size-Independent Regulatory Mechanism Density-Dependence as a Size-Independent Regulatory Mechanism

2005-04-18

arxiv.org/abs/q-bio/0504022v2

H.P. de Vladar. Density-dependence as a size-independent regulatory mechanism. J. Theor. Biol. (2006) vol. 238 (2) pp. 245-256

Biology

Quantitative Biology

Populations and Evolution

41 Pages, 5 figures Submitted to JTB

Scientific paper

10.1016/j.jtbi.2005.05.014

The growth function of populations is central in biomathematics. The main dogma is the existence of density dependence mechanisms, which can be modelled with distinct functional forms that depend on the size of the population. One important class of regulatory functions is the $\theta$-logistic, which generalises the logistic equation. Using this model as a motivation, this paper introduces a simple dynamical reformulation that generalises many growth functions. The reformulation consists of two equations, one for population size, and one for the growth rate. Furthermore, the model shows that although population is density-dependent, the dynamics of the growth rate does not depend either on population size, nor on the carrying capacity. Actually, the growth equation is uncoupled from the population size equation, and the model has only two parameters, a Malthusian parameter $\rho$ and a competition coefficient $\theta$. Distinct sign combinations of these parameters reproduce not only the family of $\theta$-logistics, but also the van Bertalanffy, Gompertz and Potential Growth equations, among other possibilities. It is also shown that, except for two critical points, there is a general size-scaling relation that includes those appearing in the most important allometric theories, including the recently proposed Metabolic Theory of Ecology. With this model, several issues of general interest are discussed such as the growth of animal population, extinctions, cell growth and allometry, and the effect of environment over a population.

Affiliated with

Also associated with

No associations

Rating

Density-Dependence as a Size-Independent Regulatory Mechanism does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Density-Dependence as a Size-Independent Regulatory Mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Density-Dependence as a Size-Independent Regulatory Mechanism will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-138043