Evaluating trans-tethys migration: an example using acrodont lizard phylogenetics.

Area of Science:

• Evolutionary Biology
• Molecular Phylogenetics
• Zoology

Background:

• Acrodont lizards, including Chamaeleonidae and Agamidae, exhibit diverse geographic distributions.
• Understanding their evolutionary history is crucial for deciphering biogeographic patterns, particularly those related to continental drift.

Purpose of the Study:

• To construct a robust phylogenetic tree for acrodont lizards using mitochondrial DNA sequences.
• To investigate the biogeographic history of acrodont lizards, focusing on their dispersal patterns linked to Gondwanan plate movements.
• To explore the evolutionary relationships between major lizard families and their geographic origins.

Main Methods:

• DNA sequencing of mitochondrial genes (ND1, ND2, COI) and intervening tRNA genes from 70 acrodont taxa and two outgroups.
• Parsimony analysis of aligned nucleotide sequences to infer phylogenetic relationships.
• Statistical examination of hypotheses regarding lizard dispersal via rafting on Gondwanan plates.

Main Results:

• Eight major clades within the Acrodonta were identified, with most agamid lizards forming three distinct clades.
• The Chamaeleonidae formed a distinct clade, weakly supported as sister to the Agamidae.
• All identified clades showed associations with landmasses derived from Gondwanaland, supporting a plate-tectonics-driven dispersal hypothesis.

Conclusions:

• The phylogenetic analysis supports the hypothesis that acrodont lizards dispersed via rafting on Gondwanan plates.
• Specific clades show clear associations with Afro-Arabia, India, Southeast Asia, and the Australia-New Guinea plate.
• These findings contribute to understanding major biogeographic themes in Asia, including vicariance and faunal exchange driven by tectonic events.