| | Category | ZO | L24 | Mitochondrial DNA Phylogeny of the Family Alligatoridae |
| | Abstract | Despite the prevalence and importance of the family Alligatoridae |
| | throughout the Americas and China, few large-scale studies including |
| | most taxa at the species and subspecies levels have been conducted. |
| | Due to conflicts between genetic and morphological characterizations and |
| | a lack of resolution in studies of phylogenetic relationships, the |
| | systematics of the family remain ambiguous. In this study, we constructed |
| | a complete phylogeny of almost all taxa within Alligatoridae using |
| | mitochondrial DNA sequences from cytochrome oxidase c subunit 1 and |
| | cytochrome b in order to resolve these ambiguities. We used sequences |
| | of DNA amplified by polymerase chain reaction (PCR) from individuals of |
| | the species Caiman latirostris, C. yacare, Melanosuchus niger, |
| | Paleosuchus palpebrosus, and P. trigonatus, and many sequences from |
| | NCBI, to construct high-resolution maximum likelihood and Bayesian |
| | inference trees, and calculate percent divergences for each gene. Our |
| | results were generally consistent with currently accepted taxonomies, but |
| | with many additional findings. We found evidence that the C. latirostris |
| | lineage diverged from Caiman soon after the divergence of Caiman from its |
| | common ancestor with Melanosuchus, suggesting that M. niger may be |
| | more closely related to C. latirostris than to other members of Caiman. |
| | Individuals highly divergent from their species were identified in both C. |
| | latirostris and P. trigonatus, which may represent distinct evolutionary |
| | lineages. We also found support for indications of hybridization between |
| | C. c. chiapasius and C. c. fuscus in northern Mesoamerica and confirm a |
| | specific clade of C. c. crocodilus identified by Venegas-Anaya et al. |
| | (2008) as being worthy of special conservation concern. Finally, we |
| | found evidence for possible admixture between C. crocodilus and C. |
| | yacare and indications that relations between them are highly complex. We |
| | advocate further research in alligatorid systematics using techniques |
| | such as microsatellites, and support efforts toward the conservation and |
| | sustainable management of crocodilians. |
| | Bibliography | Ross JP. 1998. In: Ross JP, editor. Status survey and conservation action |
| | plan: revised action plan for crocodiles. Gland, Switzerland: IUCN-The |
| | World Conservation Union. World Wide Web Edition |
| | <http://www.flmnh.ufl.edu/herpetology/CROCS/CSGpublications.ht>. |