Author: Jonathan Losos Page 22 of 130

Poor Anolis, snack box of the jungle. Seems that just about anything will eat an anole. So, it’s not surprise to learn that the teid lizard Kentropyx calcarata joins the lizard of anole consumers. So report Franzini et al. in a recent report in Herpetology Notes. Anolis fuscoauratus was the unfortunate victim, the crime discovered by examination of stomach contents.

Consider two lizard species that differ in limb length, with one species having relatively longer legs than others. During development, how does this difference arise? Do the limbs start at the same length when they first appear in the embryo, but grow at a greater rate in the longer-legged species? Or is the initial limb bud longer in the embryo of the longer-legged species, and then the rate of growth the same in the two species, preserving the initial difference?

Thom Sanger’s elegant work showed that the latter answer is correct for Anolis: the limb buds of long-legged species start out longer and then grow in parallel with those of shorter-legged species.

But does this finding also hold when comparing across a broader range of lizards? Robin Andrews and Sable Skewes decided to find out, comparing embryos of a chameleon, two geckos, and the brown anole.

The answer: the same pattern as within anoles! And it applies to tail length (but not head length) as well as limbs.

Thanks to the work of Roger Thorpe and colleagues, Lesser Antillean anoles are renowned as an example of adaptive geographic variation. On many islands in the Lesser Antilles, populations in wet areas, where vegetation is lush, are green in color, whereas those in more xeric areas tend to be a drab gray, often with markings on their back. This pattern is repeated on many different islands, the convergent geographic variation thus making a strong case for the adaptive basis of anole coloration.

See Pavitra Muralidhar’s previous post for more information on geographic variation in Lesser Antillean anoles.

In a new paper in PLoS One, Thorpe takes this work a step further, asking whether we can use the parallel patterns seen across Lesser Antillean islands to predict the coloration of an anole species on another island. The focal species is Anolis bonairensis, which occupies the extraordinarily dry island of Bonaire (see our previous posts on this species).

The prediction: A. bonairensis should be grayer and drabber than populations of anoles that occur at the driest sites on Lesser Antillean answers.

The answer: yes! Just as predicted, Anolis bonairensis is one drab lizard. Score one for evolutionary predictability!

Anolis bonairensis is represented by the red circles. The x-axis goes from aridity on the left to the most mesic on the right. As you can see, A. bonairensis‘s color and patterning is well-predicted by variation in other species.

Anolis biporcatus, one of the prettiest of anoles. Photo by Thomas Marent

Anolis biporcatus is, if I’m not mistaken, the largest mainland beta/Norops anoles, attaining a length of ca. 100 mm snout-vent. In addition, it has an enormous geographic distribution, ranging from southern Mexico to Ecuador. In a new paper in Salamandra, a team of New Mexican and Ecuadorian biologists headed by Janet Armstead have sliced off part of the species, raising the Ecuadorian/Colombian A. biporcatus parvauritus to species status. They make this decision based on a detailed analysis of morphology and molecular data. Their data also find deep genetic subdivisions within A. biporcatus in Costa Rica, suggesting that there may be more cryptic species awaiting recognition.

A key difference between the species is the color of the distal scales on the dewlap of males, white in biporcatus, black in parvauritus.

Note, too, that like many mainland anoles, the males and females have very different dewlaps.

Here’s the distribution of the two species:

Two male festive anoles (Anolis sagrei) fighting in Texas. From netscape.net‘s Facebook page.

This is reminiscent of similar battles in Sitana, like the photo below. Of course, we know all about Sitana fights here on AA.

Liam Revell has developed a method, which he explains in Phytools.

A rose by any other name would still smell as sweet. But what if there’s an anole sleeping inside of it?

Photo by Karen Cusick

Karen Cusick writes on Daffodil’s Photo Blog that she’s never seen anything like this, and neither have I.

Michele Johnson (top) and Manuel Leal (bottom). For more on the Leal lab’s march-related activities, check out the post on Chipojolab.