“Discovery of a giant chameleon-like lizard (Anolis) on Hispaniola and its significance to understanding replicated adaptive radiations”
D. Luke Mahler, Shea M. Lambert, Anthony J. Geneva, Julienne Ng, S. Blair Hedges, Jonathan B. Losos, and Richard E. Glor
Newly discovered Hispaniolan Anolis lizard suggests a novel Caribbean ecomorph
Unexpected lizard discovery sheds new light on a classic pattern of island evolution
The Anolis lizards of the Greater Antilles are famous in the biological sciences, and for good reason. Well-studied ecologically, Greater Antillean anoles are a textbook example of replicated adaptive radiation – a phenomenon in which related species evolving on different islands diversify into strikingly similar sets of species that occupy the same ecological niches (e.g., long-tailed grass dwellers, bright green canopy lizards, and stocky brown lizards that perch low on tree trunks surveying the ground for passing insects). There are six of these Anolis specialist types, and the fact that the same forms evolved independently on different islands suggests that the evolution of island communities can be deterministic. That said, not all Greater Antillean anoles have a matching counterpart on another island – roughly one-fifth of the region’s anole species stand out as ‘exceptions to the rule’. Most conspicuous among these unique lizards are Cuban anoles from the Chamaeleolis group. Chamaeleolis look more like chameleons than typical anoles. They are large, cryptic, and slow-moving, and cling to lichen-covered branches high in the canopy. There’s nothing like these Cuban lizards on the other Greater Antillean islands.
Or so we thought. In a new article in the American Naturalist, a team of researchers led by Luke Mahler from the University of Toronto report on the unexpected discovery of a large, distinctive Anolis lizard from Hispaniola. They’ve dubbed it Anolis landestoyi in honor of Miguel Landestoy, the charismatic Dominican naturalist who first observed the species and recognized it as new. The discovery of a large new lizard species on such a well-studied Caribbean island is remarkable in its own right, as Hispaniola has been well-trodden by researchers and isn’t the first place one might search for undiscovered reptiles. But that’s not the only thing that makes this lizard so interesting. Anolis landestoyi is unlike any other anole from its own island, but is strikingly similar to Chamaeleolis anoles from Cuba. Although they occur on different islands, both are large, reclusive, chameleon-like lizards that blend perfectly with the canopy branches on which they perch. Where previously Chamaeleolis stood out as a strange Cuban oddity, it now has a doppelgänger on neighboring Hispaniola.
Like the discovery of a missing puzzle piece, A. landestoyi clarifies our view of replicated adaptive radiation in anoles, adding new support for the idea that the assembly of island faunas can be substantially deterministic. Furthermore, this unexpected new lizard is a welcome reminder of the continued potential for basic discovery to reveal new insights in well-studied groups. It also highlights the urgency of such discovery for conservation. Although brand-new to science, A. landestoyi is already at risk. The new species is restricted to a unique habitat only found in a small area in the western Dominican Republic. Although it occurs within a reserve, its habitat is nonetheless rapidly disappearing due to illegal deforestation. Read the Article