What does a low heterozygosity level in a population indicate?

A low heterozygosity level in a population typically indicates a reduced genetic diversity, meaning that there are fewer different alleles present in the gene pool. When heterozygosity is low, it suggests that individuals within the population are more likely to be homozygous for certain alleles.

In this context, the presence of a common allele becomes significant. When a population has low heterozygosity, it often means that one or more alleles are dominating, leading to a situation where the frequency of heterozygotes decreases. Therefore, a population with low heterozygosity can point to the prevalence of specific alleles over others, which can have important implications for the population’s ability to adapt to environmental changes or withstand diseases.

Additionally, this scenario may arise from various factors such as inbreeding, genetic drift, or a small population size, which all contribute to reduced genetic diversity and higher frequencies of certain alleles. Thus, the correct interpretation of low heterozygosity is that it reflects a situation where one or more alleles are common, diminishing the overall genetic variation within that population.