Exploring inbreeding dynamics by considering reproductive bound and polygyny.

The article focuses on developing an expanded mathematical model to analyze inbreeding dynamics in populations by explicitly incorporating the effects of polygyny (a mating system where some males reproduce disproportionately) and female reproductive bounds (limits on the number of offspring a female can produce). Unlike previous models, this approach uses biologically realistic assumptions, modeling male reproductive success with a skewed distribution and limiting female progeny numbers, to calculate the inbreeding coefficient—the probability that an individual's homologous chromosomes are identical by descent. Numerical simulations demonstrate that the disappearance of polygyny and reductions in female reproductive bounds, correlated with increased mutation rates and population size changes, lead to long-term decreases in inbreeding coefficients, reflecting transitions from prehistoric to modern human societies. The model also predicts that shrinking populations in contemporary societies may cause inbreeding coefficients to stabilize or slightly increase, though factors like increased admixture due to globalization could counteract this trend.