Evolutsioonijõududeta

Evolutsioonijõududeta is an Estonian term describing a theoretical state in population genetics in which a population experiences no evolutionary forces, such as mutation, natural selection, gene flow (migration), or genetic drift. In this condition, allele frequencies remain constant across generations, and genotype frequencies conform to the Hardy–Weinberg equilibrium, provided other standard assumptions like random mating hold.

The concept serves as a null model for studying evolution. Under evolutsioonijõududeta, there is no adaptive change, no input of new genetic variation through mutation, and no shifts in allele frequencies due to migration or drift; thus, evolution, defined as a change in allele frequencies over time, does not occur.

Assumptions and limits: The ideal state requires a large or effectively infinite population size, random mating, no mutation, no migration, and no selection. In practice, no natural population fully meets these criteria. Even very large populations experience mutation and gene flow, and some degree of drift or selection is often present. Consequently, real populations typically deviate from evolutsioonijõududeta, and such deviations are used to infer evolutionary processes by comparing observed data with Hardy–Weinberg expectations.

Usage: The term is used in Estonian genetics literature and education to describe a baseline for assessing evolutionary change, closely linked to the Hardy–Weinberg principle as the equilibrium condition for allele and genotype frequencies in the absence of evolutionary forces.