13 Facts About Allee effect

Allee effect is a phenomenon in biology characterized by a correlation between population size or density and the mean individual fitness of a population or species.

The term "Allee effect principle" was introduced in the 1950s, a time when the field of ecology was heavily focused on the role of competition among and within species.

However, the concept of the Allee effect introduced the idea that the reverse holds true when the population density is low.

Component Allee effect is the positive relationship between any measurable component of individual fitness and population density.

The demographic Allee effect is the positive relationship between the overall individual fitness and population density.

Strong Allee effect is a demographic Allee effect with a critical population size or density.

The weak Allee effect is a demographic Allee effect without a critical population size or density.

Meanwhile, a population exhibiting a strong Allee effect will have a critical population size or density under which the population growth rate becomes negative.

In general, these Allee effect mechanisms arise from cooperation or facilitation among individuals in the species.

The anthropogenic Allee effect has become a standard approach for conceptualizing the threat of economic markets on endangered species.

The most current definition of Allee effect considers the correlation between population density and mean individual fitness.

Demographic and mathematical studies demonstrate that the existence of an Allee effect can reduce the speed of range expansion of a population and can even prevent biological invasions.

Recent results based on spatio-temporal models show that the Allee effect can promote genetic diversity in expanding populations.