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Author: Jonathan Losos Page 48 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.
An iguanito. Photo from the Coastal Star.
A nice article in the Coastal Star just reported on the spread of knight anoles through Florida. The article contains numerous nuggets, such as quotes from the Florida Fish and Wildlife Commission stating that they’re worried about bigger things (e.g., pythons, tegus), that they’re locally called “iguanitos,” and that iguanas are rebounding from freeze-caused mortality in the recent past and are mainly a problem for pooping by people’s pools.
Championship round, lightweight division. Photo from Daffodil’s Photo Blog.
We periodically post pictures, videos and stories of male anoles duking it out with each other [e.g., 1,2], but over on Daffodil’s Photo Blog is evidence that such squabbling starts at a young age. Check out how the little fellas, with barely a dewlap to speak of, nonetheless behave just the same as their elders.
Last week, Yoel Stuart and colleagues (including me) published a paper demonstrating that green anoles had rapidly (ca. 20 years) evolved an increase in toepad size as a result of upward shifts in habitat use caused the presence of brown anoles.
The Discovery Institute, an organization devoted to the advocacy of creationist views, posted a blog yesterday saying, basically, “this is not news?” After summarizing the study, here’s what they have to say:
“….these scientists found that when a new species of lizards invaded another’s territory (in fact the new species was placed there intentionally by the researchers, meaning they weren’t quite studying “natural” selection), the old one sought higher ground. That seems like a smart thing to do. To go along with the new territory, they subsequently evolved “larger toepads (see here for a picture).
After reading this, what I really wanted to see was the precise sizes of the toepad and compare the changes. But alas that information is not in the paper. I tried downloading the supplemental materials but it’s not there either. So let’s assume that the toepad size changed a lot. What have we shown?
Not much. We’ve seen that the size of lizard feet can change in response to invaders’ driving a species to perch at higher levels in the trees. No new traits arose. Only the size of a pre-existing trait changed. Again, that’s interesting but such changes in the size of lizard feet do very little to explain the origin of lizards in the first place, even if these changes happen in just a few generations.
If we take seriously the statement from the authors that the modest results from this study can help test “evolutionary hypotheses about phenomena … on time scales too long for direct observation,” then that implies that over long periods you might be able to change the size of an organism or some of its body parts. Since when is that news?”
Not many anoles have blue dewlaps, so we were delighted to see Ann Stafford’s tweet of this lovely conspersus from Grand Cayman strutting its stuff.
Anole eggs found in a tomato pot. Photo by Karen Cusick.
The egg-laying habits of anoles are surprisingly little known. On Daffodil’s Photo Blog, Karen Cusick recently reported on the discovery of eight–count ’em, eight!–anole eggs in a tomato plant pot. Readers, where else have you found anole eggs?
Also, whose eggs are these? Both green and brown’s occur in Karen’s backyard. In Anolis Newsletter V, Todd Vincent provided tips on how to tell them apart.
Brown and green anole eggs. Photo by Todd Vincent.
And for some delightful footage on baby anoles, let’s not forget this old post.
Anolis phyllorhinus. Photo by Bret Whitney
Anolis dissimilis. Photo by Paulo Melo Sampaio
In a fascinating new paper, Ivan Prates and colleagues report on a phylogenetic analysis of Amazonian Dactyloa clade anoles with implications for a number of important topics in anole evolution.
The authors generated new mitochondrial and nuclear gene data for many Amazonian Dactyloa and combined those data with existing data from previous studies. Of particular note was inclusion of Anolis dissimilis, until recently known from only a single locality, and the Amazonian horned anole, Anolis phyllorhinus.
The paper had four main results, which I’ll go through seriatim. First, the overall phylogeny is very much in accord with Castañeda and de Queiroz’s previous work. The biggest difference is that A. dissimilis occurs in a distinct clade with A. neblinus and A. calimae. A relationship between the latter two species had been suggested by the previous work; A. dissimilis had not been included in those studies. The three species have quite disjunct geographic distributions (Amazonia, western Colombia, and the tepuis of the Guiana Shield, so finding them to comprise a distinct clade is interesting.
Anolis punctatus. You can almost see a horn ready to burst forth from the tip of that snout. Photo by Arthur Georges.
Second, as the figure below illustrates, A. phyllorhinus, as expected, groups with A. punctatus, whereas A. proboscis groups with the phenacosaurs (heterodermus group; though A. proboscis is not actually included in the analysis because genetic samples were not available; however, recent studies clearly indicate that A. proboscis belongs with this clade). Prates et al. note that, other than the horn, A. phyllorhinus and A. punctatus are morphologically very similar. I’ll take that one step further–you can almost imagine the antecedents of the horn as a swelling on the tip of the snout of A. punctatus. And, in addition, note that the horns of the two-horned species are very different-looking. Although Williams placed them in the species group, he did note that they actually didn’t look at that much alike. We now know that he was correct in this observation–hornedness is a convergent trait in anoles (no, I’m not calling it horniness).
Third, Prates et al. calculated divergence times, calibrated with three fossils that can be confidently placed in iguanian phylogeny.
Posted by Lorie on Birds and Blooms.
Gunther Kōhler and colleagues have just published in Zootaxa a new revision of some Mexican anoles, including the description of six new species and the sinking of one species. Rather than describing the work, I think it would be more effective to present the title and abstract:
A revision of the Mexican Anolis (Reptilia, Squamata, Dactyloidae) from the Pacific versant west of the Isthmus de Tehuantepec in the states of Oaxaca, Guerrero, and Puebla, with the description of six new species
GUNTHER KÖHLER1, RAÚL GÓMEZ TREJO PÉREZ, CLAUS BO P. PETERSEN & FAUSTO R. MÉNDEZ DE LA CRUZ
We revise the species of anoles occurring along the Pacific versant of Mexico west of the Isthmus de Tehuantepec in the states of Oaxaca, Guerrero, and Puebla. Based on our analyses of morphological and molecular genetic data, we recognize 21 species, six of which we describe as new (i.e., Anolis carlliebi sp. nov., A. immaculogularis sp. nov., A. nietoi sp. nov., A. sacamecatensis sp. nov., A. stevepoei sp. nov., and A. zapotecorum sp. nov.). Furthermore, we synonymize Anolis forbesi Smith & Van Gelder 1955 with Anolis microlepidotus Davis 1954. Of the recognized species, six have smooth ventral scales (i.e., Anolis dunni, A. gadovii, A. liogaster, A. omiltemanus, A. peucephilus, and A. taylori) and 14 have keeled ventral scales (i.e., A. boulengerianus, A. carlliebi, A. immaculogularis, A. megapholidotus, A. microlepidotus, A. nebuloides, A. nebulosus, A. nietoi, A. quercorum, A. sacamecatensis, A. stevepoei, A. subocularis, A. unilobatus, and A. zapotecorum). In one species, A. macrinii, the ventral scales vary from smooth to weakly keeled. For each species we provide color descriptions in life, color photographs in life, descriptions and illustration of hemipenis morphology (if available), descrip-tion of external morphology, distribution maps based on the specimens examined, comments on the conservation status, and natural history notes. Finally, we provide a dichotomous key for the identification of the 21 species of anoles occurring along the Pacific versant of Mexico west of the Isthmus de Tehuantepec in the states of Oaxaca, Guerrero, and Puebla.
Karen Cusick, author of Lizards on the Fence and tender of Daffodil’s Photo Blog, writes:
You may remember that the Wild Amelia Nature Festival (Amelia Island, FL–just north of where I live) chose the green anole as their Critter of the Year for 2015. I was looking at the Wild Amelia website and they are already starting to gear up for the festival, which will be held May 15-17. They’ve designed a new website logo featuring a green anole, and there are going to be tee shirts with the logo. The website button to buy a tee shirt doesn’t work yet, but that should be fixed as the festival gets closer. I’m going to check on that.
There’s only a small size image of the logo so far, but I’m attaching it anyway. It looks like it’ll be a nice shirt.
They’ve scheduled a series of nature-based seminars in the months leading up to the festival, and the last one is May 12, when the director of the Jacksonville Zoo, Tony Vecchio, will give a presentation about the green anole and the Zoo.
I’ll let you know if I hear any more anole-related news about the festival!