Reptile & Amphibian Forums

Hallo all!
I wanted to see if I could elicit a discussion about comparisons between two more common notions held throughout many Anolis communities: do you hold that the Anolis specialists (ecomorphs like trunk-crown and twig for example) evolved independently on each island, again and again in the same fashion? Or does the notion that as sea levels rose and larger archipelagos shrunk into smaller ones, populations were forced into isolation where speciation, radiation, and adaptation occurred? How would the latter work out with new ideas on the phylogeny of this genus with DNA evidence possibly disproving the theory? What are your thoughts on these older notions in light of recent research?

Another theory rising from current research holds that as the West Indies formed through volcanic activity, anoline lizards crossed to this newly formed archipelago either by landbridge during the time when sea levels were lower, or by rafting on driftwood and debri, or were blown by storm, then were isolated as sea levels rose again after the last glacial period. There is now some convergence toward a mobilist model depicting a Cretaceous volcanic island arc that extended from Mexico/Chortis in the north to Ecuador in the south, gradually moving through the developing portal between North and South America, then colliding with the Bahamas Platform in the middle Eocene. During this 70-million-year history there was an extremely complex pattern of collision/separation and submergence/emergence that provided opportunity both for vicariance and dispersal in the migration, evolution, and speciation of the flora of the Greater Antilles.
If ongoing research continues to prove these anoline lizards immigrated from mainland South America, it will again challenge the phylogeny of the Genus and rework the taxonomic tree.