Anole Annals

Invertebrates associated with Hispaniolan anoles. Scale bar in right panel is in millimeters.

The invertebrates in the image above were photographed yesterday in the Dominican Republic. Today’s trivia is related to these invertebrates and consists of three questions:

1. What are these invertebrates and how do they interact with anoles?

2. How many individuals are in the right panel (note: all of these individuals were associated with a single anole)?

3. How do these invertebrates factor into Dominican folklore?

Hybridization in Action?

By Rich Glor

On August 15, 2011

In Notes from the Field

Photo copyright R. Glor 2011.

Perhaps this is Anole Annals’ first NSFW post, but the mating event depicted in the photo above was such an exciting observation and photographic opportunity that I can’t help but share. Yesterday we discovered a new contact zone between two phenotypically and genetically distinct populations of Anolis distichus along the Rio Bani (this contact zone is along the river’s eastern bank rather than along its well-traversed western bank). Along a narrow zone of contact (~500 m), green bodied, orange dewlapped populations of A. d. ignigularis come into contact with gray-bodied, yellow dewlapped populations of A. d. ravitergum. While sampling this contact zone, we ran across the copulating pair pictured above. The fact that the male is predominantly gray and the female predominantly green may be an indication that this is a hybridization event between A. d. ravitergum and A. d. ignigularis; genetic analyses on tissue samples collected from the pair will soon provide the answer!

If it is a hybrid pair, its likely to be more successful than others reported recently on anole anoles (e.g., A. carolinensis and A. sagrei); although hybrids between A. d. ignigularis and A. d. ravitergum are rare in nature, our captive mating experiments have yielded hundreds of eggs and offspring from matings between A. d. ravitergum and A. d. ignigularis.

Anolis scriptus- An Archipelagic Anole

By Graham Reynolds

On August 15, 2011

In Notes from the Field

Though they are not as flashy as some of their West Indian relatives, Anolis scriptus, the Southern Bahamas Anole, is an ecologically important and interesting component of the herpetofauna of the distal end of the Bahamas Archipelago. Small and brown to brownish green, they seem to be rarely photographed or discussed, so I thought they deserved a post on Anole Annals. These are individuals from the Turks and Caicos Islands- where they are ubiquitous on most emergent land- from the largest islands at over 290 square km to the smallest rocks with some vegetation. Interestingly, this species has been shown to modify its perch height in response to the presence of predators (more on predation in a later post). When curly-tailed lizards (Leiocephalus psammodromus) are around, the anoles are more arboreal (Smith 1994;1995). However, we have found this to be the case mostly on smaller islands, while on larger islands the anoles will still use the ground and lower tree trunks, even in close proximity to high densities of curly-tailed lizards.

How Many Times Have Lizard Dewlaps Evolved?

By Jonathan Losos

On August 15, 2011

In New Research

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

Stills from Anole Fight Along the Rio Bani!

By Rich Glor

On August 13, 2011

In Notes from the Field

These stills are of an anole fight we saw yesterday along the Rio Bani. This fight happened on a rock between two male Anolis distichus ravitergum. On the left, the two males are facing off. In the middle, one male is charging and biting the other. On the right, the two are tumbling down the boulder. Shea Lambert recorded the video and plans to post a version with slow-motion and music sometime soon; it should be epic.

The Anole Genome: Coming Soon To A Newstand Near You

By Jonathan Losos

On August 12, 2011

In Anoles and Anolologists in the News

Paper accepted, proofs corrected.

Next, the movie adaptation. But who will play Green Anole?

More On New Dactyloa Phylogeny

By Jonathan Losos

On August 11, 2011

In New Research

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!

Find the Anole: Phenacosaurus Edition

By Melissa Aja

On August 9, 2011

In Anole Annals Trivia

Phenacosaurus orcesi, Ecuador

Here is a shot recently taken during our first “Day in the Life of a Phenacosaur” video recording. We tracked this subadult male from 6 am to 6 pm!

Crossing the Rio Bani in Search of Anolis distichus

By Rich Glor

On August 9, 2011

In Notes from the Field

In the Dominican Republic, there are few anole hunting localities more famous than the Recodo Road, a road running along the Rio Bani just west of Bani (you can get some background on this locality from several previous blog posts 1, 2, 3). Anthony Geneva, Shea Lambert, and I arrived here on Sunday to continue our studies of speciation in the distichus species group. One feature of this road familiar to anyone who’s visited are the river crossings that are necessitated by the absence of bridges. With a 4×4, these crossings are a piece of cake when the water is low, but completely impossible when the water is high. After a recent tropical storm, both of the two required crossings are on the verge of uncrossability. We made it through the first one (see photos above), but have decided to hold off on attempting the second until the river settles a bit more. Note the beautiful Kapok (Ceiba) tree at the first crossing, which is one of the oldest and most beautiful native trees in the region (it’s also from a genus with rather remarkable transatlantic dispersal capabilities [Dick et al. 2007]). More soon on the lizards we’re seeing so far!

Chance, Fate, The Existence of God…and Anoles

By Jonathan Losos

On August 8, 2011

In Anoles and Anolologists in the News

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.