👉 In biology and genetics, an uncoalescent is a type of genetic variation that occurs between two populations (or individuals) that have not interbred for many generations. This means that there are no direct offspring produced by mating between these two populations. Instead, they pass on their traits to the next generation without passing on any genes from one generation to another. Uncoalescent variations occur when a population has undergone several generations of random genetic drift, where new mutations and changes in gene frequencies occur