Framework / Assessment California Forests and Rangelands: Proposed Indicators Summary To monitor genotypic variations in species populations. Populations with greater genetic variation tend to be able to adapt to changing circumstances and sudden environmental changes than populations with limited genetic diversity. Genetic variation may be measured by gene sequencing or morphological variation. This may be a data gap because of the intense resources that it takes to measure genetic variability, although some studies are being conducted on specific species, such as salmonids and Douglas-fir.