An Analysis of the Genome and Population Dynamics of the American Alligator, Alligator mississippiensis

American alligator

• Alligator mississippiensis

• Order Crocodylia

• Southeastern United States

• Sub-tropical environments

• Florida Everglades

Order Crocodilia

• Diverse sex-determining systems

• Exothermic

• Extreme physiology

• Most recent ancestor was 275 mya

• Mid- to upper Cretaceous Period

Why Study the American Alligator

• Genetic evolution of Amniotes

• Ancestral reptilian and amniote genomes

• Rates of Evolution

• Medical Implications

• Antibacterial Properties

Crocodilian Genome

• 16,642 Nucleotides

• Evolutionary Rate of Crocodilians

• Relationship between Birds/Crocodilians

• Divergence

Archosaur Ancestry

• Avian and Nonavian Relationship

• Avians have a smaller Genome Size

• Hox expression correlates to skeletal morphology

• Genetic Structure correlates to flight ability

Crocodilians Comparison

• American Alligator

• Saltwater Crocodile

• Neither produce sex-determining chromosomes

• Ancient Divergence in Late Pleistocene Period

Subdivisions in American Alligator Populations

• Homogenous mtDNA

• Demographic and Life History Differences

• Coastal and Inland Habitats

• East-West phylogeographic split

• Not a single cohesive population

Intra-population Variation

• Sub-tropical environments

• Differ in activity ranges

• Movement Rates

• Habitat Use

Intra-population Variation

• Consistent Behavioral Patterns

• Differences in exploration

• Effects on the Environment

• Different Ecological Roles

Conclusion• American Alligator is a Very Unique

Organism

• Dominates SE United States

• Expansive Genomic History

• Medicinal Properties

• Ancestral Archosaurs

• Social Dynamics