NEff-package: Calculating Effective Sizes Based on Known Demographic Parameters of a Population


Effective population sizes (often abbreviated as "Neff") are essential in biodiversity monitoring and conservation. For the first time, calculating effective sizes with data obtained within less than a generation but considering demographic parameters is possible. This individual based model uses demographic parameters of a population to calculate annual effective sizes and effective population sizes (per generation). A defined number of alleles and loci will be used to simulate the genotypes of the individuals. Stepwise mutation rates can be included. Variations in life history parameters (sex ratio, sex-specific survival, recruitment rate, reproductive skew) are possible. These results will help managers to define existing populations as viable or not.


Package: NEff
Type: Package
Version: 1.1
Date: 2015-05-04
License: GPL version 2.0

The package is based on function population. This function creates an individual based population model simulating genetics via a specific number of loci holding a specific number of alleles. Demography is given as input values and can be adapted to every life history parameter combination.


Annegret Grimm, Bernd Gruber & Klaus Henle

Maintainer: Annegret Grimm <>


Grimm, A., B. Gruber, M. Hoehn, K. Enders, and K. Henle. submitted to Methods in Ecology and Evolution. A model-derived short-term estimation method of effective population size for species with overlapping generations.

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