Related Experiment Video
Updated: Sep 28, 2026

Assessing Intertidal Populations of the Invasive European Green Crab
Published on: September 16, 2020
Genetic relationships of American alligator populations distributed across different ecological and geographic scales
Wade A Ryberg1, Lee A Fitzgerald, Rodney L Honeycutt
1The Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, Texas 77843-2258, USA. wryberg@neo.tamu.edu
Abstract:
Although much work has been conducted on coastal populations of the American alligator (Alligator mississippiensis), less is known about the population dynamics and genetic structure of populations of alligators confined to inland habitats. DNA microsatellite loci, derived from the American alligator, were used to investigate patterns of genetic variation within and between populations of alligators distributed at coastal and inland localities in Texas. These data were used to evaluate the genetic discreteness of different alligator stocks relative to their basic ecology at these sites. Observed mean heterozygosities across seven loci for both coastal and inland populations ranged from 0.50-0.61, with both inland and coastal populations revealing similar patterns of variation. Measures of F(st) revealed significant population differentiation among all populations; however, analyses of molecular variance (AMOVAs) failed to demonstrate any apparent geographic pattern relative to the population differentiation indicated by F(st) values. Each population contained unique alleles for at least one locus. Additionally, assignment tests based on the distribution of genotypes placed 76% of individuals to their source population. These genetic data suggest considerable subdivision among alligator populations, possibly influenced by demographic and life history differences as well as barriers to dispersal. These results have clear implications for management. Rather than managing alligators in Texas as a single panmictic population, translocation programs and harvest quotas should consider the ecological and genetic distinctiveness of local alligator populations.
Related Concept Videos
Evolutionary Relationships through Genome Comparisons
Conservation of Small Populations
Gene Flow
Genetics of Speciation
Gene Evolution - Fast or Slow?
In contrast, regions which code...
Phylogeny

