The results of the informal, unscientific, potentially bogus poll would seem to indicate that the answer is a resounding “No.”
Welcome to the first of what will be a series of primers on identifying Mexican Anolis lizards. When I was first becoming familiar with Mexican anoles, there were a few traits that stood out as being valuable for identification purposes. The goal is to make some posts outlining the traits and how to use them to identify anoles if you ever have the need. Let’s get started!
To begin, I want to stress how difficult it can be to identify many anole species in Mexico. The majority of species in the country are variable in dorsal patterning and roughly the same size (~40-60 mm SVL). On one of my early trips, I was shocked to find that four sympatric species in Guerrero had essentially identical size and dorsal patterns. Identifying them to species can be tricky if the individual in question is a female or juvenile, making it difficult to use dewlap coloration as the primary diagnostic trait for identification. Interestingly enough, one of the best ways to rule out species was to look at size and keeling of dorsal and ventral scales.
Scott Thomson, an administrator for Wikispecies, is pondering whether to adopt the proposed classification of anoles, splitting the group into eight genera, and wants to know what the community thinks. Here’s your chance to weigh in!
If you want to learn more, read Scott’s post and comments on it.
Reptiles are important models for studying phenotypic plasticity because they are quite sensitive to environmental conditions experienced during development, and naturally experience a broad range of environmental conditions during this time. There are a number of interesting biological traits of reptiles that make them particularly interesting models for research on phenotypic plasticity. For example, temperature-dependent sex determination, where incubation temperature irreversibly determines sex during development, is a fascinating polyphenism that is widespread among reptiles. Additionally, the sensitivity of developing embryos to environmental factors (like temperature or hydric conditions) has been implicated as a primary force behind the evolution of various maternal reproductive strategies including viviparity or nest-site choice. Accordingly, there exists a rich literature documenting the effects of embryonic environments on the phenotypes and survival of reptiles during early life.
A major shortcoming of this literature, however, is that the vast majority of studies terminate shortly after hatching. That is to say, our understanding of phenotypic plasticity in reptiles is biased towards phenotypes apparent in early life. Yet we rarely know if these phenotypes are persistent or transient, or if conditions experienced during development have delayed effects, or effects on reproductive traits. Together with my coauthors Fred Janzen and Dan Warner, we have recently published a review that discusses the shortcomings of terminating plasticity studies during early life, and highlights the important contributions that have come from the relatively few long-term studies in existence. We call for studies that specifically look at the effects of embryonic environments on adult phenotypes, and offer a number of approaches to address this problem.
Enter the Anole. There are a number of anole species that are very tractable models for experiments addressing the influence of embryonic conditions on adult phenotypes, reproduction, and survival. Anolis sagrei, for example, readily breeds in captivity, is highly fecund, and reaches reproductive maturity in a matter of months. Anoles are tractable for detailed assays on reproduction in the laboratory, and raising anoles from egg to adult in the lab is entirely feasible under reasonable timelines. Though it is no small task, it is very possible to incubate hundreds of anole eggs under different conditions, mark the babies upon hatching, and then release them into the field in a place where migration is not possible (like a small island). Periodically sampling that island can give insights into the effects of incubation conditions on adult phenotypes and survival under natural conditions. Phil Pearson and Dan Warner recently published a paper using such a methodology.
Of course, we also encourage such long-term studies for everyone working with reptiles, even those that are very long-lived (like turtles). But there is a dearth of studies that address the effects of embryonic environments on adult phenotypes in reptiles, and I hope that anoles are a key group that help address this shortcoming. So let’s get after it, Anolologists!!!!
Anole Annals has dropped the ball on staying current with recent papers about the systematics and taxonomy of anoles. So, here are two highlights over the last two years.
Last year, Steve Poe and 10 co-authors from five countries published a phylogeny including all species of anoles based on all available data. It was a tour de force and the paper was far-ranging, discussing the many implications of their phylogeny for anole evolution, biogeography and other topics. Among other topics, the paper sank a number of anole species, presented a phylogenetic taxonomy of anoles and argued that this taxonomy solves the problems posed in the debate on generic classification of anoles in the traditional Linnean taxonomic framework.
Here’s the abstract from that paper, published in Systematic Biology:
Anolis lizards (anoles) are textbook study organisms in evolution and ecology. Although several topics in evolutionary biology have been elucidated by the study of anoles, progress in some areas has been hampered by limited phylogenetic information on this group. Here, we present a phylogenetic analysis of all 379 extant species of Anolis, with new phylogenetic data for 139 species including new DNA data for 101 species. We use the resulting estimates as a basis for defining anole clade names under the principles of phylogenetic nomenclature and to examine the biogeographic history of anoles. Our new taxonomic treatment achieves the supposed advantages of recent subdivisions of anoles that employed ranked Linnaean-based nomenclature while avoiding the pitfalls of those approaches regarding artificial constraints imposed by ranks. Our biogeographic analyses demonstrate complexity in the dispersal history of anoles, including multiple crossings of the Isthmus of Panama, two invasions of the Caribbean, single invasions to Jamaica and Cuba, and a single evolutionary dispersal from the Caribbean to the mainland that resulted in substantial anole diversity. Our comprehensive phylogenetic estimate of anoles should prove useful for rigorous testing of many comparative evolutionary hypotheses.
This year in Zootaxa, Nicholson, Crother, Guyer and Savage published a paper following on Poe et al.’s. The paper does not have an abstract, but the title says it all: “Translating a clade based classification into one that is valid under the international code of zoological nomenclature: the case of the lizards of the family Dactyloidae (Order Squamata).” In short, the article argues that the traditional Linnean classification system is not going away any time soon, and that the clades recognized by Poe et al. are easily translatable into genera in the traditional system, as revealed in the figure above.
In a post just published, an administrator for Wikispecies asks if they should follow this proposed reclassification of anoles. If you have comments, please make them on that post.
Hi everyone. I recently received and have to determine what to do with the following paper (editor’s note, for background, see this recent post):
- Nicholson, K.E., Crother, B.I., Guyer, C., & Savage, J.M. 2018. Translating a clade based classification into one that is valid under the international code of zoological nomenclature: the case of the lizards of the family Dactyloidae (Order Squamata). Zootaxa 4461 (4): 573–586. DOI:10.11646/zootaxa.4461.4.7
As an administrator and bureaucrat at Wikispecies I have to decide how to proceed with this group of reptiles. I have made a tentative start here but please realize this is a simple start easily undone.
I recall the last time this came up, in 2012. I joined the discussion at the time. However, despite my comments at the time, I did not follow splitting the genus up then. In the end, my view is for stability and consensus. By stability, I mean the actual meaning of stability under the ICZN code, which does not apply here. But consensus could.
Why is this paper different? Well, first up, last time it was a PhyloCode paper and as such is relatively easy to ignore, as it does not submit to the rules of nomenclature. However, this time it is an ICZN compliant paper so you cannot ignore it. As stated many times, names are to considered as valid on publication or refuted–there is no ignore. So the above paper may be refuted, but not ignored.
Last time, many argued that the genus is monophyletic. This is not really an argument against splitting. It’s a position statement. The order Testudines is also monophyletic, should every turtle species (275 living species) all go back into the genus Testudo? The current genera or lack of them present are only a reference to the history of research. It does not mean it is the most suitable arrangement.
More importantly is diagnosibility. Can the new proposed genera and their inherent species be adequately diagnosed? This is a more important question.
Note that a genus with some 500 species is generally considered too big. Many writers over the years have deemed between 100-200 species about the maximum size wanted. However, this does still need to address the previous point on diagnosibility.
Another point people brought up last time was stability. Well, stability actually refers to the mononomial and whether a name can be replaced by a forgotten name. It is used as a reason to reverse priority. This is the code purpose of stability. Note that the combination first up does not have to be stable, and second is a taxonomic decision, not a nomenclatural one. Hence outside the code.
So what I am after: Basically I want to see through any commentary if the people who work on anole’s are likely to use this new nomenclature. If they are, I will adopt it at Wikispecies. That will require the moving and reorganisation of some 550 pages. I do not take that on lightly. Hence I am asking you, the people who work on anoles, first. My decision will be based on the answers I get. I do not work on anoles. I am a turtle and tortoise specialist. But I do have a job to do at Wikispecies.
For your information, I have discussed this briefly with Peter Uetz at Reptile Database also. He also was not sure what to do, but remembered the last time it came up here. So I am reaching out to all of you on this issue. I am after consensus, not stability. As I said, stability does not apply here. But I will say that to reject the nomenclatural proposals of Nicholson et al. (2018) does require a refutation. They have presented to science in good faith in a very good journal, Zootaxa. We cannot ignore this and as a taxonomist, I will not.
In advance, I thank everyone for their comments. I think this issue needs to be openly debated.
The photo above was taken by Steen Christansen and brought to our attention by the anole-loving, neuroethology-studying, mayor of South Miami, Philip Stoddard (thanks, your honor). It’s a brown anole, aka, a festive anole.
Who’s got the best caption?
Panthera, a fabulous group that works for the conservation of big cats, puts up fascinating posts on their website. This one first appeared in mid-September 2018.
September 4, 2018
Mature male leopards are at least 60% larger than females, and broader, with larger chest girths and longer, bulkier heads. But there’s something else you may notice that sets males apart: Their thick necks can be adorned with a loose flap of skin hanging underneath. These skin folds are called dewlaps.
Dewlaps are observed in a variety of species throughout the animal kingdom, most notably in certain birds, lizards, and hoofed mammals. In mature male leopards, a well-developed dewlap is prominent and one of the best ways to determine age.
However, the function of leopard dewlaps remains unknown and largely unexplored. Since they are a sexually-dimorphic feature—meaning only one sex exhibits the trait—scientists speculate that this enigmatic ornament is linked to sexual selection or male fitness.
Of another conspicuous, sexually-dimorphic feature among cats—the mane of a male lion—Charles Darwin postulated: “[It] forms a good defense against the one danger to which he is liable, namely the attacks of rival lions.”
The idea behind this hypothesis is that adaptations such as body armor or weaponry, like antlers on male deer, increase the ability of males competing against other males. Most often the winner is the lucky male who gets to mate with the female and pass on his genetics.
On the other hand, results of more contemporary research indicate that injuries sustained during fights between lions don’t appear to differ between maned and non-maned sub-adult males or even females. This outcome suggests that the mane/neck area is not a high-target region during fights. Instead, observations find that the back and hindquarters seem to be the targeted areas during confrontations.
Many biologists believe that a male lion’s mane serves as an indicator of sexual fitness. Studies using life-sized toy lions sporting contrasting mane colors and lengths found that male lions were more likely to approach the imposters with lighter, shorter manes, while female lions were drawn more to models with darker manes. These results suggest that males with shorter, blonder manes are less intimidating to rival males, and thus perceived to have lower overall fitness.
We can apply this theory to hypothesize about the functions of a dewlap on a male leopard. However, fights between elusive male leopards are rarely observed and documented by scientists. This makes it difficult to confirm if the leopard’s dewlap has any defensive functions. Likewise, it’s hard to determine if it serves a similar purpose to that of a large, dark mane in sexual selection, as an indicator of fitness and longevity.
Another speculation about the dewlap is that it simply makes mature leopard males appear larger and more intimidating to rivals. Typically, as a male leopard ages, his dewlap enlarges. Mature males hold wider territories and have more opportunity to mate with females.
This also means that there are more opportunities to come into conflict with other males seeking the same territory and females. It would be ideal to avoid physical confrontation, and potential injury, by being able to display fighting capability and fitness, thus deterring potential rivals without physically engaging them. Fighting with other males has potential to lead to injury or death. Even the smallest injuries can fester and inhibit hunting abilities, leading to a decline in body condition that could result in death.
Younger and smaller males may be dissuaded from engaging in a fight with a larger male sporting a more pronounced dewlap. Alternatively, estrous females may select a male with a larger dewlap, perceiving him to have greater fitness than his peers. As of yet, no studies have been conducted to determine if dewlap size correlates with testosterone levels or is linked to reproductive success as an indicator of longevity.
AA reader John Thomas questions whether curly-tailed lizards (Leiocephalus carinatus) actually eat anoles, based on his own observations in Florida (see comments on this post). Let’s see proof, he says! Bob Powell rightly points out the scientific literature on this topic and refers to the Schoener et al. paper from 1982 on the diet of curly-tails in the Bahamas. And here’s a photo from that paper! I’ve seen at least two other photos people have taken of such predation–anyone got more?
Hello All, I’m an ecologist that studies species-habitat relationships, among various other things. I’m presently working on a book that will describe 10 methods of statistically analyzing habitat and also try to provide a conceptual unification of how capital-E ecologists and wildlife ecologists have traditionally viewed habitat and its importance. I’m looking for real empirical datasets to analyze. Data for Anolis species would be great given their importance in testing ecological and evolutionary theory, and their specific habitat preferences. The dataset could be for a single species or multiple species. It could have either microhabitat data (e.g., observations of Anolis individuals at different perch heights and stem diameters, tree species perched on) or macrohabitat data (e.g., amount of vegetation or canopy cover within a 10 m diameter of lizard location). Really any kind of environmental or habitat data would work. Ideally, the dataset would also have environmental data from locations where lizards were not observed (so-called absence points). If you have a dataset that you’d be willing to share please contact me at joseph.veech@txstate.edu. THANKS!