Are the Data Sufficient to Split Anolis into Eight Genera?

Yesterday, I summarized the points made in Nicholson et al.’s recent Zootaxa rebuttal. To me, there are two main issues stemming from this paper. I’ll discuss the first today and the second tomorrow.

The first question is whether the eight proposed genera are monophyletic. There has been much criticism on this point in our pages and this was a central point in Poe’s critique. Nicholson et al.’s response strongly lays out their contention that all studies in recent times have found evidence for the same eight groups. They claim that there are very few species whose position is uncertain, not enough to worry about.

At this point, I personally don’t think it’s worth expending more effort arguing back-and-forth on this matter. Both sides have made their points. In a few years, we’ll have a lot more data on anole systematics and we’ll find out who’s right. If Nicholson et al. are correct that only a few species are in play (i.e., moved from one of their genera to another, as they have already done with A. christophei), then they’ll be vindicated. If they’re wrong and there are major upheavals to their preferred phylogeny, then their proposal will be seen as premature and misguided.

I don’t see the point in arguing this one any further.

The Battle Over Anole Classification Continues

For those of you who have been living under a rock for the last two years, here’s the short story. In 2012, Nicholson et al. published a monograph in Zootaxa on anole systematics and evolution that proposed dividing Anolis into eight genera. This paper has been much discussed and criticized in these pages (this might be a good place to start). In turn, Poe replied in Zootaxa with a critique widely considered to be overly aggressive in tone. Now, Nicholson et al. have responded to Poe in a nicely written rebuttal that for the most part clearly draws the lines on the areas of disagreement.

This Zootaxa paper is behind a pay-wall, so I thought it might be worthwhile to provide a summary of the main points of the paper in today’s post. In the next two posts, I will discuss what I see as the major issues moving forward.

I’ll summarize Nicholson et al.’s paper following their sections:

Introduction

The authors introduce the paper by citing Poe’s critique and stating: “We acknowledge that science benefits from vigorous, intellectual debate, but would have preferred his commentary to be more constructive, objective, and scientifically accurate. We therefore present this rebuttal to explain how Poe erred in characterizing our work, and missed the opportunity to present an alternative comprehensive taxonomy to replace the one against which he argues so strenuously. In this contribution we explain, and correct, Poe’s errors and misrepresentations, and argue that our taxonomy is likely to be adopted because it 1) eliminates the obvious problem that will arise if the family Dactyloidae contains only a single large genus (i.e., that a single genus obscures the evolution and diversity within the group and misrepresents or cloaks it), 2) conforms with the long historical trend of dissecting large, cumbersome groups into smaller sub-units, 3) is consistent with all recent phylogenetic studies for anoles in membership within clades we recognize as genera, and 4) aids in associating these lizards with the ancient land masses that shaped their history.”

I would only comment on this introduction by saying that criticizing Poe for not providing an alternative taxonomy seems off the mark. Poe made very clear what he thinks the preferred taxonomy is—one in which a single genus Anolis is recognized.

Monophyly and Anole Taxonomy

The paper begins by taking on the criticism that some of their eight genera are not monophyletic. They point out that for any group which has been the subject of multiple studies, there always will be some disagreements about clade membership. They review how they handled these disagreements: “We did not always follow one particular analysis or dataset (i.e., only follow the molecular data or only the Bayesian analysis) because, as systematists, we are all aware that there are always shortcomings in both the data and the analyses, especially when considering large, cumbersome groups. We integrated the available information to make these predictions, and these explanations are included in the systematic section for each group. Morphological and molecular data often disagree, and investigators are left to interpret those results.”

Character Diagnoses for Clades

This section rebuts Poe on a rather technical point about whether it is sufficient to cite diagnostic characters for a clade when those characters are identified from only one of many possible equally likely trees. Although an interesting debate, it is of minor significance compared to the bigger issues under discussion.

Recognition of Monophyletic Groups across Studies

This is the most important, and most original, part of the paper. The authors state: “Eight major clades are recovered in all studies that have broadly sampled anole taxa (Alföldi et al. 2011; Jackman et al. 1999; Nicholson et al. 2005; Poe 2004), including Pyron et al’s (2013) monumental reassessment of the Squamata. We classified these clades as separate genera because clade membership is so remarkably consistent among analyses, as is membership in 21 of 22 subgroups that we recognized within these genera (Figures 1–5). There are 12 species out of the 240 included in our combined molecular and morphological analysis that are unstable with respect to generic designation in our molecular-only tree, or other recent molecular-only phylogenies.”

Upon further examination of the 12 problematic species, the authors conclude that only “… 5 species that we placed in the genera Anolis (argenteolus, cyanopleurus, lucius, and spectrum) and Chamaelinorops (christophei) …may potentially, eventually, warrant different generic assignments than those we recommended.” Moreover, in a Note Added in Proof at the very end of the paper, the authors state “The recent analysis of several large datasets leads us now to recommend placing the species christophei into our genus Xiphosurus rather than in Chamaelinorops as we suggested in our 2012 paper.” This point refers to the recent papers by Pyron and Burbrink and Gamble et al., recently discussed in our pages (see comments). The authors conclude on this point: “Poe notes that node support for some of the eight major clades of anoles is weak, and concludes that more data are required to justify them. We continue to argue that the consistent recovery of eight dominant clades of anoles in multiple independent studies is sufficient justification for recognizing eight genera. In our view, the pattern is clear; the accumulation of additional data is going to recover these same eight genera.”

The most novel and important part of this paper is the figures 1-5, which show that, for the most part, the same eight clades have been detected time and time again. Here, for example, is the phylogeny from Jackman et al. (1999):

comparison to Jackman et al

And here’s a comparison to Poe’s own work: Continue reading The Battle Over Anole Classification Continues

Anoles (and Other Lizards) at SMBE 2014

SMBE2014-600x360The annual meeting of the Society for Molecular Biology and Evolution meetings start this weekend in San Juan, PR and there are a number of talks and posters to appeal to the squamatophile.

There are three presentations from AA contributors (Marc Tollis and Tony Gamble) using anole genomic data, as well as posters and talks on phylogeography of Puerto Rican Sphaerodactylus, and genome-scale studies of Sceloporus, skinks, and snakes. You can see the full list after the jump.

Continue reading Anoles (and Other Lizards) at SMBE 2014

Tongue Protrusion in Battling Male Anolis limifrons

limifrons displaying doc frogDoc Frog (a.k.a. Cesar Barrio Amorós) has the most amazing balcony anywhere. Previously, we posted photos of Anolis biporcatus mating and A. charlesmyersi being beautiful, taken from that overlook. Now the good doctor reports photographs of anoles taken not from his balcony, but on his balcony. Specifically, two male A. limifrons in a tense encounter.

We’ve had posts in the past of other anoles sticking their tongues out in male-male encounters (e.g., A. fuscoauratusA. stratulus). I wonder how widespread it is in the anole kingdom. I am unaware of any review of this topic, but the first place to start would be Schwenk and Mayer’s paper, “Tongue display in anoles and its evolutionary basis,” published in Anolis Newsletter IV.

Who else can report tongue use in anole displays?

limifron males combatting doc frog

New Papers on Convergent Evolution

Convergent evolution is Anolis Lizards’ middle name, and so it is with great interest that we read two brand-spanking new papers on convergent evolution. The first is by  Arbuckle et al. out of the University of Liverpool. Published in Methods in Ecology and Evolution, the paper describes a new method for quantifying the strength of convergent evolution. You’ll have to read the paper for the details, but the gist of the method is that convergence is greatest either when species are greatly different phenotypically from other species or when the convergent species are distantly related phylogenetically.

And the focal taxon used to demonstrate the method with empirical data? Why, none other than Greater Antillean ecomorphs. The paper found that in “In Anolis lizard data set, perhaps the most notable finding is that ecomorphs differ in the strength of their convergence—grass-bush and trunk-ground anoles stand out as having particularly strong convergence compared to others. Furthermore, some traits are more strongly convergent within some ecomorphs but not others. Therefore, patterns of convergence in particular traits are ecomorph specific.” Specifically, “analyses found the strongest convergence in limb length occurred in grass-bush anoles compared to the other ecomorphs, consistent with Losos’ (1990b, 2009) finding of relationships between limb length and jumping and sprinting (perhaps particularly important for grass-bush anoles). The strong convergence of lamellae number detected in trunkground anoles suggests that there is a notable degree of adaptation in this trait.”

The abstract of the paper is appended at the bottom of this post.

Meanwhile, in a non-anole example, Collar and colleagues, in a paper in the American Naturalist, looked at convergent evolution in snail-eating moray eels. The authors found that the durophagous eels evolved in generally the same direction morphologically relative to their non-snailivorous relatives, but that there was substantial variation among the shell-crackers, actually more variation than seen among their relatives.

collar figure

The authors explain this “imperfect convergence” in this way:  “we show that following 10 transitions to durophagy (eating hard-shelled prey) in moray eels (Muraenidae), cranial morphology repeatedly evolved toward a novel region of morphological space indicative of enhanced feeding performance on hard prey. Disparity among the resulting 15 durophagous species, however, is greater than disparity among ancestors that fed on large evasive prey, contradicting the pattern expected under convergence. This elevated disparity is a consequence of lineage specific responses to durophagy, in which independent transitions vary in the suites of traits exhibiting the largest changes. Our results reveal a pattern of imperfect convergence, which suggests shared selection may actually promote diversification because lineages often differ in their phenotypic responses to similar selective demands.”

Such imperfect convergence is not unknown among anoles. For example, Langerhans et al. showed that despite the convergence among the ecomorphs, there were also island-specific effects that produced variation among members of an ecomorph. Moreover, a larger scale example is the comparison of mainland and Greater Antillean anoles. Is the lack of convergence due to environmental differences, or is it an example of species evolving different adaptations to living in the same environment?

Exciting times for those of us interested in convergent evolution!

The abstract of the Arbuckle et al. paper: Continue reading New Papers on Convergent Evolution

New Ecuadorian Anole Named After Steve Poe

poei

And it’s a looker!

mapThe species, described recently in Amphibian & Reptile Conservation by Fernando Ayala-Varela and colleagues, comes from the western slope of the Andes in Ecuador. In appearance, it’s most similar to A. gemmosus, which occurs to the north. Detailed examination shows it to be most phenotypically similar to that species and A. otongae, and DNA analysis indicates that A. gemmosus is its sister taxon.

Check out the paper, which has lots of lovely photos not only of the new species, but of some of the species with which it is sympatric.

 

dewlaps

Where Do Sitana Sleep?

Sleeping Sitana

Sleeping Sitana

If you’re in the field looking for lizards, knowing where they sleep can be tremendously useful. Anyone who’s tried catching an anole at night knows how much easier this can be than catching it during the day.  When I began working with Sitana, therefore, I was keen to locate where these lizards slept. Being primarily terrestrial, it made sense that they would sleep under rocks, in cracks in the ground, or buried beneath grass, bushes, or leaf litter. I had some indirect evidence for the utilization of these locations as sleeping sites–I had seen lizards emerging from and retreating to these locations early in the morning and late in the evening, respectively.

However, I did not expect that fan-throated lizards would sleep completely in the open on the ground. Yet that is precisely what my colleague Divyaraj Shah recently observed. You can see the lizard’s head pointing downwards, resting on the ground below–he does not seem disturbed at this point.

Is it common for terrestrial lizards to sleep in open, unsheltered spots?

Distribution of Keratins in Lizard Scales

Keratins are the structural proteins of skin, hair, nails, feathers, and scales. There are 54 described  keratins in humans, a subset of which has also been found in the green anole genome. Distinct combinations of keratins in skin appendages are what give these tissues their unique properties such as flexibility, rigidity, or cornification (i.e., the process of forming an epithelial barrier). Lizards have a number of specialized scale types, likely due to the distinct distribution of keratins in those scales. Dating back at least a decade, Lorenzo Alibardi and colleagues have been making great progress describing the keratin gene family in lizards and describing the distribution of these proteins across the body. Alibardi has recently added to this long series with a description of keratin localization in the lamellae of Anolis carolinensis. Because I am not an expert in keratin biology I will let the Abstract give you the details:

ABSTRACT Knowledge of beta-protein (beta-keratin) sequences in Anolis carolinensis facilitates the localization of specific sites in the skin of this lizard. The epidermal distribution of two new beta-proteins (betakeratins), HgGC8 and HgG13, has been analyzed by Western blotting, light and ultrastructural immunocytochemistry. HgGC8 includes 16 kDa members of the glycine-cysteine medium-rich subfamily and is mainly expressed in the beta-layer of adhesive setae but not in the setae. HgGC8 is absent in other epidermal layers of the setae and is weakly expressed in the beta-layer of other scales. HgG13 comprises members of 17-kDa glycine-rich proteins and is absent in the setae, diffusely distributed in the beta layer of digital scales and barely present in the beta-layer of other scales. It appears that the specialized glycine-cysteine medium rich beta-proteins such as HgGC8 in the beta-layer, and of HgGC10 and HgGC3 in both alpha- and beta layers, are key proteins in the formation of the flexible epidermal layers involved in the function of these modified scales in adaptation to contact and adhesion on surfaces.

Fig. 10 from Alibardi 2014

Fig. 10 from Alibardi 2014

 

Evolution Program Released: Anoles Are Back in Strong Force

I may have given the Evolution 2014 logo an Anolis upgrade.

I may have given the Evolution 2014 logo an Anolis upgrade.

It’s that time of year again! The annual Evolution meeting is upon us. In just under a month, scientists from around the world will converge on Raleigh, North Carolina to learn about new and emerging trends in evolutionary biology. As with the Society for Integrative and Comparative Biology meetings, anoles have had a strong presence at Evolution. It appears that this year will be no different. A quick search for talks including the terms “anole” or “Anolis” yielded seven presentations, and so this meeting should be quite fruitful for those of us interested in what’s new and exciting in Anolis. You can view the list of scheduled presentations here – simply put Anolis into the keyword search at the bottom and all seven presentations will be displayed. Or just look below. As in previous years, we’ll be blogging live from the conference, so stay tuned.

Screen Shot 2014-05-28 at 7.08.36 PM

Screen Shot 2014-05-28 at 7.08.26 PM

brown anole

Female Preference in the Brown Anole

As a senior in college I wanted to study courtship behaviors, and the brown anole (Anolis sagrei) piqued my interest. In going through the literature, I noticed that some studies reported finding evidence for the presence of female choice in brown anoles and others reported that female choice didn’t occur in the species. So I decided to see if females exhibited a preference for males based on two different characteristics: male physiology and male territory quality, each of which would provide females with different benefits. I expected that females would choose males based on territory quality, because females usually mate with the males whose territories overlap theirs in the wild.

I tested for female preference in two different choice experiments using anoles that I ordered and had sent to my college, Colby College, in Maine. I was given access to a small storage closet (which I cleaned out) in the basement of Colby’s biology building in which I kept my crickets and anoles. To test for differences between males with different physiological traits, I tested male endurance by placing them on a treadmill and running them until they couldn’t run any longer. This was perhaps one of the most stressful parts of the experiment for me, since the lizards really didn’t like being put on the treadmill, so during this part of the experiment I got to chase many lizards around the room.

A brown anole running on a lizard treadmill

A brown anole running on a lizard treadmill

I then paired similarly-sized males with very different running times to see if females spent more time with one male over the other. For the preference tests, the males were tethered to posts in a mate choice box originally constructed for zebrafinches, and the females were able to run freely through the box.

In the territory tests, rather than pairing males with different endurance scores, I randomly placed males on the side of the box with many plants and twigs, or on the side without. In both tests, I recorded the amount of time females spent on either side as well as the behaviors of the males and females (I watched many hours of video to score behaviors).

This is the mate choice arena for the territory quality experiment

Mate choice arena for the territory quality experiment

My results were somewhat surprising; I found that in both experiments the more active male was the most preferred one. This was contrary to my prediction, especially since our measure of activity included all male behaviors, not just courtship behaviors. This is not surprising in the broader scheme of mate choice, since active mates are often preferred, and it’s interesting to see how anoles fit into the bigger picture of mate choice and sexual selection in general. This study is now published, so check it out if you’re interested in the details! Please feel free to contact me if you have any questions or would like a copy of the pdf.

Japalura – The Many Shades

Northeast India is a rather unexplored place even though it boasts huge biodiversity, mostly due to the numerous rivers and mountains that dot the landscape and form formidable barriers to dispersal. A majority of the taxa found in this region still await valid descriptions. I have been working on amphibians in the state of Arunachal Pradesh (one of the seven states that form the ‘Northeast’) during my undergraduate years and during my field work, I came across some very striking gular color morphs of the genus Japalura. The genus Japalura consists of 26 species which range from Northeast India in the west to Japan and Taiwan in the east, north to Shaanxi province in northern China and south to northern Vietnam. Of these, four species have been so far reported from Northeast India.

From the photographs taken in the field, Ulrich Manthey identified all of them as belonging Japalura andersoniana. If all of them are the same species, the variation in the gular coloration indeed comes across as striking. There was a note in Sauria (Bhosale et al 2013) that listed various morphs, but no speculations on what could be the possible causes. I have seen these lizards in Eaglenest Wildlife Sanctuary (EWS) and Talley Valley Wildlife Sanctuary (TVWS). The published note has color morphs from another place – Kamlung Wildlife Sanctuary (refer to the map for relative locations of the two places within Arunachal Pradesh)

The locations of Eaglenest Wildlife Sanctuary, Talley Valley Wildlife Sanctuary and Kamlung Wildlife Sanctuary

The locations of Eaglenest Wildlife Sanctuary, Talley Valley Wildlife Sanctuary and Kamlung Wildlife Sanctuary

The observations for each specimen with the corresponding number from #01- #05 is summarised from my field notes. Note: All the animals were encountered opportunistically; there was no dedicated sampling effort toward lizards whatsoever. Elevation recorded from a Casio altimeter watch.

Fig 2.

The different color morphs of Japalura species – The field notes are listed corresponding to #01-#05

#01 – EWS, June 2012, Adult, It is the most commonly occurring color morph in EWS. I have also seen juveniles with similar throat colors, Seen in the elevation range 1100m – 1600m asl.

#02 – EWS, May 2012, Adult, encountered at an elevation of around 1800m asl. I haven’t come across a second individual resembling this throat coloration.

#03 – EWS, June 2012, Juvenile, encountered at around 1990m asl; I have never encountered an adult with such coloration.

#04 – Juvenile, throat not very well developed, could possibly be a female, encountered at an elevation around 1350m asl where I have encountered larger individuals with no throat color.

#05 – Juvenile, however, an expedition the previous year by a different group found an adult with similar throat color, the only color morph seen in Talley Valley.

Even if they are the same species, it is quite possible that the different throat color morphs are divergent populations breeding in isolation, especially because apart from #01, the other color morphs have been reported from only particular localities. It is also important to survey more of the Northeast to see if the unexplored areas are home to novel throat color morphs. Speculations with just a few records would be rather vague.

New Paper Provides Standardization of Anole Systematic Characters

Gunther Köhler has just published a paper in Zootaxa describing the many characters used in anole species descriptions. Here’s how he explains the endeavor:

Anolis are important research organisms and many articles are published every year dealing with different aspects of the biology of these lizards. However, at this point we still lack detailed and standardized descriptions of all recognized species of Anolis. The species descriptions found in original descriptions, reviews of species groups, or faunal treatments are extremely heterogeneous in regard to content, usage of terms, semantic issues, and characters included. For example, some authors (e.g., Underwood & Williams 1959; Savage & Villa 1986; Köhler 2008) count the number of subdigital lamellae under Phalanges II–IV whereas others (e.g., Schwartz 1973; Williams 1995; Poe et al. 2012) report only the lamellae under Phalanges II and III. Even when the same characters are reported, often differences in definitions are evident with different authors scoring the same character differently, i.e., having different threshold levels for scoring qualitative characters (e.g., whether to consider a scale to be smooth, faintly, or weakly keeled, or not, slightly or distinctly enlarged relative to adjacent scales). Also, the way the data are generated can differ widely depending on the applied methodology. In 1995, Williams provided definitions for 37 morphological characters intended for usage in a computerized key for anoles. Williams’ (1995) approach aimed mostly to bring definitions and encodings of morphological characters usable in a computer program. Therefore, he was forced to simplify many of the included character states thereby masking the extent of variation actually observed in the genus Anolis. This article aims to provide definitions of external morphological characters that are useful in Anolis taxonomy with the goal of establishing a reference for future taxonomic work with these lizards. I am confident that a description containing the set of characters defined here will be reasonably complete for the majority of species. In species that show special morphological differentiations (such as the rostral appendage in A. proboscis), these special features need to be addressed of course. I have included many images illustrating the variation in the characters discussed, although I do not attempt to provide a comprehensive review of the variation in external morphology in anoles.”

A variety of morphometric characters from snout-vent length and head width to postcloacal scale width. Here’s one as an example:

Diameter of parietal scale. The longitudinal (LDP) and transverse (TDP) diameters of the parietal scale are measured. LDP and TDP both are measured at the greatest length and width, respectively. Slender projections of the parietal scale should be ignored in cases where these are beyond the normal concave or convex outline of the scale.

The heart of the paper is a description of a large number of scalation characters and their various alternative states. For example:

Condition of supraocular scales (CSO). These vary from smooth or rugose to weakly or strongly keeled; keeling can be uni- or multicarinate. Examples are given in Fig. 12.

Condition of circumorbital scales (COS). In many species of anoles, a row of small scales separates the enlarged supraocular scales from the scales of the supraorbital semicircles. Thus, this character refers basically to the scales situated medially to the enlarged supraocular scales; laterally to the enlarged supraocular scales usually numerous small scales are present without differentiated scales that can be identified as circumorbitals. Considerable intra- and interspecific variation can be observed in this character as exemplified in Anolis dunni (Fig. 13) with the circumorbital series varying from complete (one or more rows of scales) to incomplete or absent. Whenever one or more enlarged supraocular scales are in contact with scales of the supraorbital semicircles, the circumorbital series are incomplete or absent.

circumorbital

And one more set of examples:

Number of scales between supraorbital semicircles (IO). In most species of anoles a pair of semicircular series of enlarged scales is present in the frontal region between the supraocular discs. The minimum number of scales between the supraorbital semicircles is determined (i.e., usually at the narrowest point; Fig. 22).

Number of scales between supraorbital semicircles and interparietal plate (IP/IO). The minimum number of scales between the supraorbital semicircles and the interparietal plate is determined (Fig. 22). This character obviously is ignored in species that lack a differentiated interparietal plate (e.g., Fig. 22B).

Size of scales adjacent to interparietal plate (ScIP). The relative size of the scales surrounding the interparietal plate is noted. In some species the size of the scales anterior to the interparietal plate differs from those situated posteriorly to it. See examples in Fig. 22.

interparietal

This looks to be a very useful contribution, particularly as the number of newly described anoles continues to rise.

More Missing Limbs and a Lizard Slumber Party

Several days ago, I reported on skeletal anomalies from this year’s trip to the Bahamas and wondered what cool stuff we might see next. Much to my surprise, the next surprise turned up the very next day, in the form of Mexican anole maestro Levi Gray, making his first appearance in the Caribbean. Welcome to the big leagues, Levi!

The next night, Levi strolled down to our place to do some night herping–and wouldn’t you know?–en route the very first Anolis smaragdinus he had ever seen turned out to be of the three-footed variety. Add another example to our parade of limb-reduced anoles.

smaragdinus bahamasx

Later on, while out looking for more greens, we came across this pair of lizards snoozing.

sagrei sleeping threesomex

But closer examination shows that that’s not a pair, but a trio, with one anole sleeping on top of another. Now, that’s something I’ve never seen before!

sagrei doubledeckerx

Lastly, my favorite shots of the trip, now finished.

Anolis sagrei. Photo by Jonathan Losos

Anolis sagrei. Photo by Jonathan Losos

Anolis distichus. Photo Jonathan Losos

Anolis distichus. Photo Jonathan Losos

Anolis smaragdinus. Photo by Jonathan Losos

Anolis smaragdinus. Photo by Jonathan Losos

curlyx

 

 

Anole Phylogeny Activity for High School/College Level

phylogeny-example-geography-color

Hello, Anole Annals readers,

I work for the Howard Hughes Medical Institute’s Science Education Department. To support the anole film that Jonathan Losos talked about on this post, we developed a classroom activity to explore the morphology and the phylogeny of Caribbean anoles using photographs and DNA sequences. The resources are available from our BioInteractive.org website.

Students are given color photographs to sort different anole species into ecomorphs. Having grouped the species, they use an online phylogeny tool to build a phylogenetic tree from the DNA sequences from the same species. The results show that different species from the same islands cluster together, independent of the ecomorphs, suggesting that the ecomorphs are examples of convergent evolution. I’m sure Anole Annals readers are well-versed in this, but we tried to make the research accessible to high school teachers and students. Teachers are always looking for evolution resources that use actual DNA sequences.

Anole trading cards, used in the classroom exercises.

Anole trading cards, used in the classroom exercises.

Bahamian Lizards Reduce the Amplitude of Their Headbobs in the Presence of Predators

blogphoto

The Anolis literature is replete with examples of lizards altering the properties of movement-based displays in response to fluctuations in environmental conditions. Anoles modulate head-bob amplitude based on social context (Fleishman 1988) and social spacing (Stamps and Barlow 1973, Steinberg & Leal 2013), and head-bob speed based on background vegetation motion (Ord et al. 2007) and many other habitat variables (e.g., Ord et al. 2010). Our recent paper adds predation pressure to this growing list of factors that might affect the signal properties of anoles. Continue reading Bahamian Lizards Reduce the Amplitude of Their Headbobs in the Presence of Predators

Spotlight on Cuban Anoles, IV: Anolis allisoni

_1040037-2

Anolis allisoni, close relative of our friendly neighborhood A. carolinensis, is a remarkable lizard. It’s also no stranger to Anole Annals, and the populations found off the coast of Honduras were just featured here. We saw a lot of these lizards in Cuba, and the post is pretty picture heavy, so join us after the jump for blue-headed lizards.

Continue reading Spotlight on Cuban Anoles, IV: Anolis allisoni

Blue Head, Pink Dewlap

…can mean only one thing: Anolis allisoni. I’ve been trawling through twitter today. Searching on “anole” is no longer useful–the term’s been hijacked by very exuberant tweeters talking about the comic book character’s latest sexploits, but a search on “Anolis” still yields dividends. Including a nice article, in Spanish, on A. allisoni from the Cayos Cochinos off the coast of Honduras (discussed previously on AA). Included are some nice photos, like the one above, and several videos.

Anole Performance Meta-analysis!

http://onlinelibrary.wiley.com/doi/10.1002/ece3.528/full

Example of a three-task Pareto front in a 3D morphospace, Figure 9 in Sheftel et al 2013.

 

I want all of your old performance data.

Who am I? I am a Ph.D. student and the thrust of my dissertation project is to arrive at a better understanding of how selection, trade-offs and constraints act on suites of performance traits, leading to adaptive phenotypic shifts in populations and, ultimately, evolutionary change. I am particularly interested in constraints imposed on performance evolution by intralocus sexual conflict, and in the relationship between preferred and maximal performance.

What am I going to do with it? I am conducting a meta-analysis of existing performance data, which involves mapping suites of performance traits onto lizard morphospace and fitting a multivariate response surface. This surface can then be used (by everyone!) to predict trade-offs between different types of performance traits in various selective contexts, and to identify regions of morphospace associated with performance peaks and valleys. These areas, and the taxa that occupy them, would thus be of interest in terms of looking for behavioral compensation or other solutions. Conversely, areas of morphospace devoid of extant taxa may be indicative of insurmountable constraints or something even more interesting. Such insights will, I hope, inform more exploratory, experimental and comparative avenues of investigations.

I’m focusing on Anolis in particular to start with, and I’d like to quantify the relationships between the span of extant anole morphology and any and all whole-organism performance traits. But to do this, I need data! Lots and lots of data! And I don’t have enough :( Which means I need your data.

What I need:

 Raw data1 from previously published studies involving performance trait data along with morphological2 measurements for any and all Anolis species would be very useful and much appreciated. The more coverage of morphospace/performance space, the more useful and powerful the model!

If you’ve ever measured any of the following performance traits in anoles, you’ll probably be getting a grovelling email from me, but just in case you have somehow escaped my scrutiny, or don’t want to wait for the grovelling email, here is what I am looking at:

  • bite force
  • sprint speed
  • acceleration
  • endurance
  • exertion
  • maneuverability
  • jumping
  • climbing
  • clinging

Performance data for multiple traits measured in the same individual will be the most informative, but I will also need plenty of data on single performance traits. I have few other standards (as far as this project goes), so anything will be useful!

Thanks so much for reading this far! I sincerely hope this piques your interest and inspires you to share your work with me. I will of course be open to discuss any and all aspects of data-sharing, collaboration and subsequent use or availability of the data. All contributing authors will be acknowledged and papers cited, or whatever else is necessary! If you have anything you would like to contribute please feel free to contact me directly @ acespede@uno.edu.

1 I can use raw data files, in whatever format (e.g., .xls, .txt., .sys, .jpg of a lab notebook or rum-stained bar napkin).

2 I would be happy with anything from SVL-only to comprehensive measurements for individual limb components, toe pad area, etc. Body size and limb measurements are ideal!

(Figure from Sheftel, H., Shoval, O., Mayo, A., Alon, U. 2013. The Geometry of the Pareto front in biological phenotype space. Ecology and Evolution, 3(6): 1471-1483)