According to NOAA, the eye is over Abaco right now, with sustained wind speeds of 115 mph
Author: Jonathan Losos Page 115 of 130
Professor of Biology and Director of the Living Earth Collaborative at Washington University in Saint Louis. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.
Doesn’t look good. Staniel and particularly Abaco are right in the path of Irene–Category III for Abaco. Hang in there, lizards and people!
AA readers may recall a series of post this past May, in which I discussed research on anole ecology and evolution in the Bahamas. Those posts discussed studies that have been ongoing in Abaco for several years on the effect of predators (curly-tail lizards) on anoles, as well as studies initiated this year to the south in Staniel Cay.
Hurricane Irene, predicted to reach Category IV status, is now bearing down on the Bahamas from the south. And if you examine the hurricane’s track, you’ll see that she is aiming right at our study sites. What will happen? In the past 13 years, we’ve had three experiments terminated by hurricanes. Please cross your fingers, toes, and any other extremities in hopes that fourth time is a charm.
The field of anole ecomorphology was born 50 years ago this month when Bruce Collette published his pathbreaking paper, “Correlations between ecology and morphology in anoline lizards from Havana, Cuba and southern Florida” in the Bulletin of the Museum of Comparative Zoology. It was this paper that first explicitly detailed the relationship between morphology and habitat use in Anolis lizards and this was the start of the research program of Rand, Williams, Schoener and others that today has made Anolis a textbook case of ecomorphological diversification. Indeed, because the term “ecomorph” itself can be traced to Ernest Williams’ classic 1972 paper (see p.56 of Lizards in an Evolutionary Tree), in many respects, this month represents an important landmark in the development of the field of ecological morphology.
So, what did the paper say? The summary says it all: “This paper has attempted to correlate ecology with morphology in six species of Anolis from southern Florida and Havana, Cuba. It is felt that with proper ecological data, valid correlations can be made that can lead to an appreciation of the significance of characters often used in taxonomic analysis. Also, light is shed upon the structural adaptations that allow related sympatric species to occupy the same geographical area without facing deleterious competition. It has been shown that selection has acted so that lizards will usually match the color of their natural background. Examples have been shown to support the idea that peritoneal pigmentation is connected with exposure to radiation. The value of long legs to terrestrial lizards has been shown. Short relative tail length has been correlated with arboreality. The more arboreal members of a group of sympatric species have been shown to be larger and have more lamellae than terrestrial species. Data have been presented to support the contention that increased numbers of lamellae are an adaptation to increased arboreality.”
And who was this Bruce Collette?
Polychrus gutturosus flashing its stuff. Photo from http://www.bijagual.org/images_reptiles/reptiles_image_links/pages/polychrus_guttorosus_3_JPG.htm
One interesting implication of the recent finding that Anolis and Polychrus are not closely related concerns the evolution of the dewlap. The two genera were long thought to be close relatives in part because they both possess what appear to be similar dewlaps. The new phylogeny indicates that these structures are not indicative of common ancestry, but rather that the two clades have convergently evolved very similar structures.
Dewlap-like structures have, in fact, evolved repeatedly in iguanian lizards (the clade that contains iguanids [in the old, broad sense], agamids, and chameleons). Some of these dewlaps are different from that of anoles—such as the flap of iguanas and the triangular dewlap of Draco—but the dewlaps of the agamid genera Sitana and Otocryptis are dead ringers for those of anoles. In fact, one might argue that Sitana out-anoles anoles with its regal fan pictured below.
Sitana ponticeriana. Photo by Niranjan Sant from Lizards in an Evolutionary Tree
Paper accepted, proofs corrected.
Next, the movie adaptation. But who will play Green Anole?
Barely even kissing cousins: A. aequatorialis on the left and A. fitchi (photo thanks to Chris Funk) on the right.
The new Castañeda and de Queiroz phylogeny of Dactyloa is an important advance in our understanding of anole phylogenetics. Prior to this paper, relationships among clades within Dactyloa had been little studied; indeed, the monophyly of Dactyloa was in question, with a viable alternative being that Dactyloa is a paraphyletic group from which the rest of Anolis sprang. Not only have Castañeda and de Queiroz convincingly laid this possibility to rest, but they have identified five strongly supported clades. As the previous AA post on this paper noted, these clades are geographically coherent, revealing five geographically distinct theaters of Dactyloa diversification.
The paper has important implications in several other respects:
1. Size evolution: Dactyloa is known for its giant anoles (officially defined by Lazell as an anole exceeding 100 mm in snout-vent length). Almost all giant Dactyloa belong to the latifrons clade, all members of which, save one, are giants.
2. Convergence: In a number of cases, species that were thought to be closely-related were found to occur in different clades. The most amazing of these are A. aequatorialis and A. fitchi (pictured above), so similar in appearance and ecology that they were thought to be sister taxa that replaced each other on opposite sides of the Andes. However, it turns out that they are not at all closely related and belong in different clades.
3. Evolutionary divergence: an underexplored aspect is the extent of evolutionary diversification within clades of Dactyloa. Though much remains to be learned, it is clear that diversification has been quite extensive, as a number of the clades contain an ecomorphological array of species. The Western clade, for example, contains species such as festae, peraccae, chloris, aequatorialis, and gemmosus, which are very distinct from each other morphologically and utilize different parts of the structural habitat. Collecting the necessary morphological, ecological and behavioral data to trace the pattern of Dactyloa radiation will be an exciting challenge in the coming years!
In sum, this paper importantly advances our understanding of anole evolution. If now we could only crack that Norops nut!
Unidentified anole by Miguel Landestoy from the Philadelphia Inquirer. Who can name that species (not Miguel!)?
Faye Flam’s Planet of the Apes column in today’s Philadelphia Inquirer is entitled “Is Life Inevitably or Chance? Lizards May Tell.” Turns out that anoles may hold the answer to some of life’s most profound questions.
Phenacosaurus orcesi. Photo by Melissa Woolley.
As I prepared for our current trip to Ecuador to study the natural history of Phenacosaurus orcesi, I feared that we would not find any lizards. After all, until recently, the species was known from only two specimens. What if we simply couldn’t find them?
These fears were assuaged when I reviewed the literature—scant as it is—on phenacosaur ecology. In the most comprehensive study, Miyata found 77 P. heterodermus individuals in blackberry bushes in five afternoons of observations at a site near Bogota. On seeing the previous AA post, Vic Hutchison also recalled finding P. heterodermus in blackberry bushes in Colombia. George Gorman mentioned to me that he collected phenacs in a suburb of Bogota in the summer on 1968, and he recalls that “it was a like Lesser Antillean experience…rather than a ‘mainland’ experience, in that the lizards were abundant, easily collected, and on fenceposts and hedges.” In addition, the original description of P. vanzolinii states that “the local people say that the ‘camaleon o camaleon’ is common in the fields of maize.”
From all of this information, I formed the hypothesis that finding phenacs would be easy, that we’d be awash with data and would finish so early that we could go traipsing off elsewhere in Ecuador. In other words, I set myself up for the Principle of Unsympathetic Magic to rear its ugly head, and it did so with a vengeance.