Greater Antillean anoles would not be a model system for studies in ecology and evolutionary biology without the foundation provided by a century and a half of careful work by anole systematists. Because their contributions often go unrecognized, I thought I’d use this post to call attention to the work of some of the most important figures in Greater Antillean anole systematics. I’m going to focus here on alpha-taxonomy, and specifically on description of new species (we’ll do later posts on the history of anole phylogenetic systematics and descriptions of subspecies). The majority of the nearly 120 species of anoles found on Cuba, Hispaniola, Jamaica, and Puerto Rico were described by five key figures and their colleagues.
Reproductive cycle of Anolis trinitatis, from Licht and Gorman (1970).
All anoles lay only a single egg at a time, but that doesn’t mean that no variation exists among species in reproductive cycles. Still the most comprehensive study of this topic is Licht and Gorman’s (1970) comparison of nine populations of seven species throughout the Caribbean (downloadable as part of AA’s “Classics in Anole Literature” Initiative—pdf contributions welcome!). They found that reproductive activity was most constant through the year in the two southernmost species examined, A. trinitatis and A. griseus from St. Vincent. In the remaining species, both sexes showed some degree of seasonal fluctuations, although reproductive activity by at least some individuals occurred in almost all months. The authors considered rainfall to be the primary factor driving variation in reproductive activity, although in a later paper, they reconsidered and suggested that seasonal temperature cycles were probably more important.
Despite the ease with which such data could be collected, relatively few studies in the past four decades have followed up on this work. One such study on a Colombian anole was featured in AA recently, but for the most part, little work of this sort has been conducted in recent years. Who knows what surprises await an anole comparative reproductive biologist?
Recently AA asked George Gorman for some thoughts on this work, and he provided the summary below of the several papers he and Paul Licht wrote in the first half of the 1970’s on anole reproductive cycles:
Licht and Gorman. 1970. University of California Publications in Zoology 95:1-52.
Famous figure from the Williams (1972) paper in which the term "ecomorph" was introduced.
I just read another paper that uses the term “ecomorph,” this one in reference to populations of insects. We anolologists know that Ernest Williams introduced the term “ecomorph” in his classic 1972 paper (available here), defining an ecomorph as those “species with the same structural habitat/niche, similar in morphology and behavior, but not necessarily close phyletically.” The terms “ecomorph” and “ecomorphology” are now widely used. Was Williams really the one who coined the term? And is its current use consistent with the ideas he developed?
Herpetological Review has recently made available all the covers going back to the advent of color photographs in 1995. I found them on <a href=”https://www.facebook.com/media/set/?set=a.180287091987312.50983.178914018791286″>Herp Review’s Facebook page</a>. As far as I could tell, this shot of Anolis tranvsersalis from the Sept. 1999 issue is the only anole to grace an HR cover. Time for another one, I’d say!
The field of anole ecomorphology was born 50 years ago this month when Bruce Collette published his pathbreaking paper, “Correlations between ecology and morphology in anoline lizards from Havana, Cuba and southern Florida” in the Bulletin of the Museum of Comparative Zoology. It was this paper that first explicitly detailed the relationship between morphology and habitat use in Anolis lizards and this was the start of the research program of Rand, Williams, Schoener and others that today has made Anolis a textbook case of ecomorphological diversification. Indeed, because the term “ecomorph” itself can be traced to Ernest Williams’ classic 1972 paper (see p.56 of Lizards in an Evolutionary Tree), in many respects, this month represents an important landmark in the development of the field of ecological morphology.
So, what did the paper say? The summary says it all: “This paper has attempted to correlate ecology with morphology in six species of Anolis from southern Florida and Havana, Cuba. It is felt that with proper ecological data, valid correlations can be made that can lead to an appreciation of the significance of characters often used in taxonomic analysis. Also, light is shed upon the structural adaptations that allow related sympatric species to occupy the same geographical area without facing deleterious competition. It has been shown that selection has acted so that lizards will usually match the color of their natural background. Examples have been shown to support the idea that peritoneal pigmentation is connected with exposure to radiation. The value of long legs to terrestrial lizards has been shown. Short relative tail length has been correlated with arboreality. The more arboreal members of a group of sympatric species have been shown to be larger and have more lamellae than terrestrial species. Data have been presented to support the contention that increased numbers of lamellae are an adaptation to increased arboreality.”
“We have not far to go, indeed, to find our bi-colored masquerader; see the emerald-clad scamp as he eyes you from the brawny limb of the pecan, under which you stand. But what is he up to! You quietly watch him, and his employment seems to be of such a nature that he soon completely ignores you, and proceeds with it at all risks, and at all costs. The mystery is soon solved, and we can readily appreciate this agitation, this bowing and strutting, and all manner of quaint motions, as if the very last drop of his quaint lacertilian blood was on fire—for coyishly, and with all due deference, reclines before his lordship, his chosen mate, exerting all her chameleonic powers to hide her blushes by vain endeavors to match the colored pattern at her command. He can withstand her charms no longer, and for the moment, laying aside all dignity, and the object of his affections not unwillingly submitting, in the next instant finds herself in the passionate embraces of her lord, who, to make sure that he has actually won his coveted prize, winds about her lithe form, perhaps in some mystic love-knot, his entire caudal extremity, and blinds her eyes, first on one side and then on the other, by extension of the flaming ornament at his throat.”
Ok, you can’t actually find this on the bookstand at the local grocery store. Rather, it’s from a paper by a captain in the U.S. Army Medical Corps, R.W. Shufeldt, published in the American Naturalist in 1883. Romantic interludes notwithstanding, the paper presents a remarkably accurate and detailed report of the natural history of A. carolinensis (in which he referred to the green anole as the American chameleon, Anolis principalis).
Anolis nitens (formerly A. chrysolepis). Photo from http://www.sciencephoto.com/images/download_lo_res.html?id=907650178
Today I had a chat with an evolutionary biologist who specializes on the evolution of tropical forests. We were discussing the effect of climate change on the Amazon, and he first made the point that dire warnings about the Amazon are possibly slightly overstated. Yes, the rainforest may be in big trouble, but it’s not as if the trees will fall down and the area turn into barren desert. Rather, there are many dry-adapted tree species in South America, and they will probably take over, replacing wet forest with dry forest. Conversation then turned to what is known as the Pleistocene Refugia Hypothesis (PRH), the idea that during the ice ages, the climate became drier because so much water was locked up in glaciers. As a result, so the theory goes, rainforests were fragmented as the forest was replaced in many places by other habitats. As a result, a formerly widespread species might become isolated into multiple, unconnected populations. The PRH suggests that these isolated populations often evolved into different species, and the famously high species richness of the Amazon may be a result of high rates of speciation resulting from a series of cycles of forest contraction and expansion. The PRH, however, has fallen on hard times for a variety of reasons, and I think it is safe to say that most workers in the field no longer favor it. Nonetheless, my colleague averred that the hypothesis has been too hastily discarded; in his mind, the idea has been caricatured, and more reasonable versions of the idea have merit and deserve more attention.
Core areas of A. chrysolepis distribution in the Amazon. Map H from Vanzolini and Williams (1970)
Of course, this conversation immediately turned my mind to one thought: anoles! In particular, it reminded me of two significant, yet in recent years little read, papers on Amazonian anoles. The first was a 1970 monograph in Arquivos de Zoologia by Paulo Vanzolini, famed Brazilian herpetologist and samba composer, and Ernest Williams on the pan-Amazonian anole then referred to as A. chrysolepis, now known as A. nitens, and soon to be divided into several species (stay tuned to these pages for more on that as the story develops).
Wade Davis, explorer extraordinaire, made his name as a graduate student at Harvard by proposing not only that Haitian zombies were real, but that they were created by ingesting concoctions that include tetrodotoxin, the toxin in pufferfish and the infamous Japanese delicacy, fugu. When the victim recovers (if he does), he believes he has become a zombie, and this belief is then taken advantage of by the voodoo priest.
Davis first reported his hypothesis, controversial to this day, in a 1983 paper. In that paper, he reports the results of three expeditions to Haiti, in which he documented the preparation of five separate zombie potions in four different villages. The process by which the potion is created is an elaborate and intricate ceremony, which the gentle reader may learn about by reading the aforementioned paper. For our purposes here, the interesting issue is the ingredients that go into the potion.
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!
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.
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
