the.com/genetic drift

means The random change in how common different gene versions are in a population from one generation to the next, caused by chance events rather than natural selection.

from 'Genetic' traces to Greek 'genesis,' meaning origin or birth. 'Drift' comes from Old Norse/Old English roots meaning to be driven or carried along, like wind-blown snow or a boat without a rudder — apt, since the term describes populations being pushed around by chance rather than steered by selection. The specific scientific phrase was shaped in the early 20th century as population geneticists, notably Sewall Wright, worked out the math of how allele frequencies wander randomly in finite populations, especially small ones.