Avkomfordeling

Avkomfordeling, or offspring distribution, is the distribution of the number of offspring that individuals contribute to the next generation in a population. It is a way to describe how reproductive success is spread across individuals, not just the average fecundity.

Key concepts include the mean number of offspring per individual and the variance of that number. In many natural populations, reproduction is highly skewed: some individuals produce many offspring while others produce few or none. This skewness is often summarized by the variance or coefficient of variation in offspring number. The shape of the distribution can be modeled with different statistical forms, such as Poisson, negative binomial, or lognormal distributions, depending on the species and context.

The avkomfordeling has important implications for population genetics and evolution. A high variance in reproductive success reduces the effective population size (Ne) relative to the census size, increasing genetic drift and the rate of inbreeding. Conversely, a more even distribution of offspring tends to preserve genetic diversity. The concept intersects with mating systems, life history, and environmental variation, which all influence how offspring are allocated among individuals.

Applications span ecology, conservation, and breeding programs. In conservation, understanding avkomfordeling helps assess extinction risk due to reduced Ne. In selective breeding, practiced mating biases can dramatically alter the distribution of offspring, affecting genetic gain and diversity. Data for estimation come from pedigrees, parentage analyses, and lifetime reproductive records.

See also: effective population size, reproductive success, offspring distribution models, population genetics.