Figure 2. Population assignment of known breeding individuals revealed assignment bias from unequal effective sample sizes. Circles represent the breeding populations (colored), with circle size representing effective sample size, and arrows represent the assignment of individuals from their known breeding population to their assigned population. Arrows are scaled in size by the number of individuals assigned. Colored arrows represent the correct individuals assigned to a breeding population, whereas black arrows indicate incorrect assignment to a different population. A) When using all samples to calculate allele frequencies in breeding populations, all incorrectly assigned individuals (n = 18) were assigned to a population with higher effective sample size. B) Standardizing breeding populations by sample sizes (27 individuals per population) resulted in less incorrect assignment (n = 5), but all individuals were still assigned to another population with higher effective sample size. C) Standardizing breeding populations to approximately the same effective sample size (~12 effective individuals), resulted in only one individual being incorrectly assigned. In all cases, incorrect assignment was typically to a geographically neighboring population.