Year: 2011 Page 35 of 42

About a week ago, an esteemed foreign colleague asked if I had a PDF of Ernest Williams’ famous 1983 Lizard Ecology book chapter on the evolution of the anole ecomorphs. I didn’t, nor did anyone else to my knowledge, so I scanned it today. In doing so I was able to renew my appreciation for just how LONG this gem is – nearly FIFTY PAGES including refs. I hope that no one ever has to scan it again!

To that end, readers may now find scans of this long-out-of-print work here. It comes in two flavors: slightly higher resolution or OCR text-searchable. Enjoy!!

PS. As a teaser, here’s Figure 2 – the ubiquitous ecomorph figure that’s found its way into countless anole presentations over the past quarter century.

Parapatry, Species’ Geographic Ranges, and the Green Anoles of Hispaniola

By Jonathan Losos

On March 21, 2011

In New Research

Anolis chlorocyanus (photo @ Rich Glor). Anolis chlorocyanus occurs north of Mertens' Line, A. coelestinus to the south. Map on right (from Glor and Warren, 2011) illustrates that suitable conditions for both species occur in the range of the other species (the warmer the color, the more suitable the area).

Many sets of closely related species exhibit a geographic distribution in which species only come into contact at their range border, with one species replacing another across the geographic landscape. Such a “parapatric” distribution could be explained in many ways, such as:

1. The species are adapted to different environments, and their distributions reflect geographic differences in environmental conditions;

2. The environment does not change geographically, but the species are so ecologically similar that neither is able to displace the other from its current range;

3. The species are not reproductively isolated; when they come into contact, they interbreed, thus preventing coexistence;

4. The species are newly-arisen, and have not yet expanded their ranges into sympatry, or one species has not yet displaced the other completely.

A case in point are the large green anoles of Hispaniola, Anolis chlorocyanus and A. coelestinus. Except for their dewlap, these two trunk-crown species are nearly identical in morphology, and they also occupy similar structural habitats. Yet, A. coelestinus occurs only in the southern peninsula, whereas A. chlorocyanus occurs throughout the rest of the island.

More microsatellite markers

By jjkolbe

On March 18, 2011

In New Research

Sequencing of the Anolis genome holds great promise for unlocking the genetic basis of anole phenotypic variation – such as dewlap coloration and limb length differences – and it also makes for a nifty way to discover new molecular markers, such as microsatellites. Wordley et al. report in a recent article on mining A. carolinensis expressed sequence tags (ESTs) for repeats and then blasting the EST-derived sequences against the genome to obtain the genomic sequence and its location on assembled chromosomes. From these sequences, they designed primers, tested them out in A. carolinensis, and, importantly, attempted to amplify them in multiple, phylogenetically diverse species. They identified 8-25 new variable markers for apletophallus, carolinensis, distichus, porcatus, and sagrei, which can be added to the existing resources designed for carolinensis, cristatellus, distichus, luciae, roquet, oculatus, and sagrei, which also work for some related species. Happy genotyping!

When an anolologist goes mouse trapping…

By Melissa Aja

On March 18, 2011

In Notes from the Field

from Michele Johnson:

Two weeks ago, I had the opportunity to join one of my colleagues, mammalogist David Ribble, in the data collection for a vertebrate biodiversity survey he’s working on at Bamberger Ranch in Johnson City, Texas. (Incidentally, David is a grad school pal of Jonathan Losos – it’s always a small world.) We trapped rodents, checked pitfall traps, lifted cover boards, and jumped out of the truck when we saw snakes in the road. This was my first experience trapping mammals, and I was impressed by the many similarities, and the important differences, between field studies of rodents and anoles.

This is not an anole. It’s a Peromyscus pectoralis from Bamberger Ranch, with a fresh ear tag.

The similarities:

1. When you grab an animal, it pees on you.

2. If you don’t hold on tight, the animal gets away. (The perils of working with students…)

3. If you don’t hold on right, you get bitten.

4. When you catch males, you confirm the sex by everting the penes.

5. Tails can come off – oops!

6. We all pose our specimens in unnatural positions. (Mice get a “Superman flying” pose; anoles a “mid-jumping jack” pose.)

7. Field work is better with beer.

The differences:

1. You can lure mice into little traps using food. It would be awfully convenient if anoles fell for such a trick.

2. If an anole bites your finger, you can blow on its face until it lets go. If a mouse bites your finger, you bleed all over everything.

3. Male mice only have one penis, poor guys.

4. If takes way more work to make a mouse specimen than an anole specimen – you have to skin it, stuff it, and pin it. I prefer fixation with nasty chemicals.

Assuming my lists are exhaustive, it’s clear that the study of anoles has more similarities than differences with the study of their amniotic brethren. Still, I think I’ll stick with anoles.

PS – For those of you wondering, the rodents we trapped were Sigmodon hispidus (cotton rat) and Peromyscus pectoralis (white-ankled mouse), and the herps we caught were Sceloporus undulatus, Acris crepitans blanchardi, and Thamnophis proximus. It was very cold that weekend.

Find the Anole: Disney World Edition

By Rich Glor

On March 17, 2011

In Anole Annals Trivia

This shot was taken by anole biologist Todd Jackman on Main St. USA during a recent trip to Disney World. Can you spot the anole?

All About Sleeping Anoles

By Jonathan Losos

On March 16, 2011

In Classics from the Literature, Natural History Observations, New Research

Anolis princeps sawing logs in Ecuador.

There have been a number of posts recently discussing various aspects of the sleeping biology of anoles (e.g., here, here, and here). Anoles spend 1/3 to 1/2 of their lives asleep, so it is not surprising that there is a small cottage industry of research papers describing where they sleep, in what position, and with whom. The most recent addition to this genre is a very nice paper on A. uniformis in Mexico, which reveals that this species is typical in sleeping on leaves with its body in line with the long axis of the leaf. The paper includes a brief, but thorough review of the literature on anole sleeping and thus is a good entrée to the literature.

A somewhat less brief review of the literature might go something like this

Visualizing Anole Convergence in Morphospace

By Jonathan Losos

On March 15, 2011

In New Research

Evolution of species in a two-dimensional morphospace. Axes are from a principal components analysis of morphology; symbols represent different ecomorph classes.

Over on the Phytools blog, anole biologist and comparative methods guru Liam Revell provides a program to visualize the evolution of traits in multivariate space, termed a “phylomorphospace.” This method plots species’ values and connects the points to portray their phylogenetic relationships. Most imporantly, the example he uses is none other than Greater Antillean anole ecomorphs, using a figure developed by Luke Mahler and pictured above. The diagram above illustrates convergence of the ecomorphs by showing that members of the same ecomorph class occur in the same parts of morphological space, even though many members of each ecomorph are not closely related to each other. Each large dot represents an extant ecomorph and the color indicates ecomorph class; small dots are internal nodes of the phylogeny. Admittedly, these spaghetti-grams can be hard to follow for large phylogenies, but they do give a sense of how traits have evolved and the extent to which convergence occurs.

More on Mainland Anole Predation

By Agus Camacho

On March 14, 2011

In Natural History Observations

In the Western Andes of Colombia one of the most common bird species is the Black-billed Thrush (Turdus ignobilis, known as Mirla).

In the picture, a Mirla is eating an anole and although it is hard to see what anole species it has in its beak, it is possible to say what species it is not. In this particular locality (vereda Chicoral, Valle del Cauca, Colombia, 1700 m) three anole species occur sympatrically –Anolis ventrimaculatus, A. eulaemus and A. antonii. The first two are frequently found inside forest fragments and to a lesser extent it is possible to find them in the edge forest, but never in crops or cultivable lands, but the third species, A. antonii, a fuscoauratoid anole, is easily found in the edge forest and in crops (tea crops in this case) and very hard to see inside the forest. This picture was taken by my friend Giovanni Chavez-Portilla which he kindly shared with me. It was taken from a second floor of one country house in this locality in November 2008.

The Anole’s Pajamas

By Jonathan Losos

On March 13, 2011

In Classics from the Literature, Natural History Observations

Anolis gemmosus from Mindo, Ecuador

One of the reasons that spot-lighting for anoles at nights works so well is that many anole species adopt a lighter color in the evening. This was first noted by Reverend Lockwood in an article in the American Naturalist in 1876 who noted that his captive anoles were usually brown during the day, even when on a green leaf, and were green at night, even when sleeping on brown surfaces. He concluded (p.13): “The belief that the color of the contiguous object is mimicked for the sake of protection is, I think, not confirmed by the observed facts. The truth is that in this matter of animals enjoying life there is a higher law than that of mere intention. I shall call it the law of spontaneous expression, which has its base in another law, to wit, that a joy unuttered is a sense repressed. Why should green be the favorite night-gown of our sleeping Anolis? I timidly venture the suggestion that it is because the animal is disposing itself for the luxury of sleep, its color changes being the utterances of its emotions . . . Whether it be the expression of enjoyment of repose, comfort, or emotional joy, the highest manifestation is its display of green.”

Photo Caption Contest

By Jonathan Losos

On March 11, 2011

In Natural History Observations, New Research

We’ll all give a big hand to whomever provides the best caption for this photo. While you’re ruminating about something clever, notice that this adult male Anolis sagrei, collected from an introduced population in Taiwan and reported on here, is quite fat and sassy (or at least fat). Clearly, the extra appendage did it no harm. Who knows, maybe it even helped! Many anoles with three legs have been collected over the years (more examples always welcome). The existence of five-legged anoles means that it is now statistically possible to examine the relationship between limb number and sprint speed. Stay tuned.