Professor of Biology and Director of the Living Earth Collaborative at Washington University in Saint Louis. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.
Photo by Dick Bartlett.
Dick Bartlett found this lizard a week ago, deep in the rainforest along the Rio Mazon, Dpto Loredo, Peru. He says “The blue irises initially indicated transversalis but the more I’ve thought about it, the more unsure I have become.” Anyone able to identify it?
Phelsuma guimbeaui from Mauritius.
Despite the brilliant colors, the natrual history of day geckos (Phelsuma) is little known. The most recent issue of Herpetological Conservation and Biology includes a very nice study on the habitat use of two Mauritian species, showing that they are most abundant in native forest and pointing out that, thanks to their pollinating services, they are keystone species. An interesting point is that even though day geckos are essentially Old World anole doppelgängers, in their habitat use they differ in rarely leaving the trunks of trees. One of the authors is legendary ornithological conservationist Carl Jones, almost single-handedly responsible for preventing the extinction of several Mauritian bird species.
Here’s the abstract:
Many fragile ecosystems across the globe are islands with high numbers of endemic species. Most tropical islands have been subject to significant landscape alteration since human colonisation, with a consequent loss of both habitat and those specialist species unable to adapt or disperse in the face of rapid change. Day geckos (genus Phelsuma) are thought to be keystone species in their habitats and are, in part, responsible for pollination of several endangered endemic plant species. However, little is known about key drivers of habitat use which may have conservation implications for the genus. We assessed the habitat use of two species of Phelsuma (Phelsuma ornata and Phelsuma guimbeaui) in Mauritius. Both species showed a strong affinity with tree trunks, specific tree architecture and are both restricted to native forest. Tree hollows or cavities are also important for both species and are a rarely documented microhabitat for arboreal reptiles. Both P. ornata and P. guimbeaui avoid areas of high disturbance. Our data suggest that active conservation of Phelsuma requires not only the protection and restoration of native forest, but also implementation of forestry practices designed to ensure the presence of suitable trees.
We’ve had a number of previous posts on orange-colored brown anoles, but here’s a nice blog post that discusses them a bit further, with a bonus photo of a yellowish green anole. Christina Chappell, the majordomo of serenityspell.com, reports that the lizard was seen in the northern part of the Everglades. And, no, in case you’re wondering, the photo was not altered in any way.
The Faculty of Arts and Sciences at Harvard University has a quaint but lovely tradition of reading a “memorial minute” to honor deceased members of the faculty. I recently came across the minute concerning Ernest Williams, which was presented in 2009 and published in the Harvard Gazette.
At a Meeting of the Faculty of Arts and Sciences on May 19, 2009, the following Minute was placed upon the records.
Ernest Williams was a man of many contrasts. Biology at Harvard in the third quarter of the last century was full of outsized personalities—titans in the field with strong opinions and no reservations about expressing them. In such company, Williams appeared a wallflower, seemingly wishing to be anywhere but in the midst of their arguments. Yet, one-on-one, Williams had an incisive wit and a dry sarcasm—discussions with him were always stimulating and provocative as he never missed a chance to challenge one’s thinking, sometimes quite pointedly.
To some, Williams’s work came across as old-fashioned. His subject, systematics — the study of the evolutionary relationships of species—is among the oldest in science, and his papers — florid and opinionated and, above all, long—recalled an approach to scholarship no longer in vogue. Yet much of his work was boldly innovative; some papers are still widely cited, and in several cases his work was well ahead of its time, presaging approaches to the study of evolutionary biology that were not to catch on for several decades.
Ernest Edward Williams was born January 7, 1914, in Easton, Pennsylvania, the only child of middle-aged parents. Like many boys, particularly of that time, he grew up loving nature and spent many hours capturing salamanders and other creatures. After attending Lafayette College, Williams joined the Army, serving in Europe during World War II. Upon his return, Williams entered graduate school at Columbia University, where he was the last graduate student of the great anatomist William King Gregory.
Williams’s doctoral thesis focused on the structure of the neck vertebrae of turtles and how variation among species reflects their evolutionary heritage. The work demonstrated the combination of careful attention to detail with the ability to interpret results in the broader context that was to characterize Williams’s career. More than fifty years later the work is still foundational in understanding the evolution of turtle diversity.
In 1950, after completing his degree, Williams moved to Harvard, where he initially served as a laboratory coordinator for the anatomy course of the legendary paleontologist Alfred Sherwood Romer, then subsequently was appointed as an assistant professor and made coordinator of a General Education course on evolution. The Museum of Comparative Zoology’s Curator of Herpetology, Arthur Loveridge, retired in 1957, and Williams was appointed to take his place. In 1970 Williams rose to the rank of professor and in 1972 became Alexander Agassiz Professor of Zoology.
Williams initially focused on continuing his work on turtle systematics, leading to a series of publications including a still-important treatise published with Loveridge in 1957. Williams soon realized, however, that the museum’s collections were inadequate for the detailed analysis he conceived, which required large samples from many populations. This recognition that the museum’s herpetological collections were wide in scope, but lacking in depth, led Williams in two directions. First, it compelled him to work greatly to expand the Herpetology Department’s holdings, ultimately leading to a quadrupling of the department’s collections (to more than 300,000 specimens) by the time he retired as curator in 1980, making the Museum of Comparative Zoology (MCZ) one of the greatest herpetological repositories in the world. Second, it led Williams’s attention to focus on lizards in the genus Anolis, a very species-rich group from the Caribbean and Central and South America. A previous curator of herpetology and director of the MCZ, Thomas Barbour, had extensively collected anoles in the Caribbean; Williams, whose focus was much more evolutionarily-oriented than most systematists of the day, recognized that this group could be a model for studying large-scale evolutionary and biogeographical phenomena.
And, indeed, they were, and still are.
Photo by Miguel Landestoy, from the New Yorker’s website
Well, actually it first came to light during a BBC expedition to film solenodons, but more recent legwork by AA contributor Miguel Landestoy has rediscovered the animals near Pedernales in western Dominican Republic. Miguel’s efforts are chronicled in a delightful article in the New Yorker.
2014 was a good year for AA. 220,000 viewers in 195 countries (and that doesn’t count the 200 subscribers who get each post hand delivered to their email inbox–sign up now!*), 307 new posts, 1570 page views on one day. Guess which post that was? And who do you think the most frequent commenter was, with 76 comments? WordPress has kindly provided a list of information and stats, which you’re welcome to peruse.
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The big question–were they making s’mores?
The first anole paper of 2015 is a doozy. Everyone loves to roast marshmallows around a campfire. Turns out that “everyone” includes crested anoles, A. cristatellus! Read all about it in the paper by Norman Greenhawk in the new journal Life: the Excitement of Biology.
Photo by Julia Klaczko
This is an article wrtten by Stephanie Pappas and posted on livescience. It reports on a paper just published in the Journal of Zoology by Julia Klaczko, Travis Ingram, and me:
A lizard’s penis evolves six times faster than any of its other parts, a new study finds.
The study is the first to directly measure the evolution rate of the penis of any species, though researchers have long suspected that the male genitalia evolve faster than other body parts, said study researcher Julia Klaczko, a biologist at the University of Campinas in Brazil.
“What we see is, sometimes, very close species have very different hemipenes or genitalia,” Klaczko told Live Science. Hemipenes are the pair of organs that make up the version of a penis found in snakes and lizards. But dramatic genital differences are seen among closely related animals with penises, as well. [The 7 Weirdest Animal Penises]
Quick-changing penises
Because penises are often so different even in species that otherwise look almost identical, researchers frequently use genitals to discriminate between different species. Klaczko and her team chose to measure the genitals of 25 species of Anolis, a group of lizards that live in the Caribbean. Anolis lizards are a well-studied group, and researchers have lots of information about the relationships between the species, as well as their habitats and body shapes, Klaczko said.
The lizards’ hemipenes are tubular structures with a groove through which semen can flow. The researchers measured the length and width of the hemipenes in several specimens of each species. For comparison, they also measured the length of the lizards’ limbs, which evolve in response to the vegetation in the animals’ habitats, and the size of their dewlaps, which are the flaps of tissue near the throat that the lizards use for communication.
Next, using mathematical modeling, the researchers estimated the rates of evolution necessary to arrive at the differences in genitals, limbs and dewlaps. The result
? Male genitalia change six times faster than either legs or throat flaps, making them more diverse in shape and size from one another than the other body parts.
Picky females or sexual warfare?
Klaczko and her colleagues aren’t sure what drives the rapid alterations in hemipenes. One possibility is that females pick mates with pleasing penises, whether that means their genitals are more stimulating or abetter “fit” in the female genitalia.
Another, less cooperative, possibility is that male and female lizards are locked in an evolutionary arm’s race in which both are trying to control reproduction. If this is the case, then males may be evolving genitals that give them an advantage in fertilization, while females evolve their genitals in an attempt to take that advantage back.
One known example of such a sexual arms race is the duck. Some duck species have corkscrew vaginas that spiral in the opposite direction of the males’ corkscrew penises, so the females can better resist unwanted mating attempts.
So far, the researchers haven’t studied female Anolis genitals, in part because vaginas are just harder to dissect and measure than hemipenes, Klaczko said. The next step, she said, is to try to understand the drivers in the variation in hemipenes’ shape and whether it has to do with differences in habitat, relationships between species, or some other factor.
The researchers reported their findings Jan. 5 in the Journal of Zoology.
Another news article on this research was just published on the Discovery News website.
Anolis allisoni displaying. Photo by Pablo Bedrossian
Sister WordPress blog pablobedrossian has a nice post with photos and videos of A. allisoni from Los Cayos Cochinos in Honduras.
Introducing Anolis alocomyos.
Gunther Köhler and colleagues have done it again!This time, they’ve taken Anolis tropidolepis in Costa Rica and divided it into three species in the December 2014 issue of Mesoamerican Herpetology.
The back-story: the A. pachypus complex (as the authors refer to it, except using the generic name Norops) has in recent years been split in Panama into four species, but complex member A. tropidolepis remained intact in Costa Rica. These lizards are long-limbed, narrow-padded lizards found near the ground at high elevations.
Based on eight years of collecting, Köhler and colleagues now split the group in Costa Rica into three species that are somewhat genetically differentiated at the 16s mitochondrial gene and that differ in hemipenial morphology and to some extent in scalation. One of the OTUs (operational taxonomic units), comprised of a single individual, has the mtDNA of one species and the hemipenis morphology of another and is interpreted as evidence of hybridization.
The paper includes interesting discussion of bar-coding and how one goes from degree of genetic differentiation to decisions on species delineation.
One highlight of the paper was the icon shown below, which occurred at the bottom of one of the pages at the end of the article without explanation. A quick look at the other two papers in the issue revealed that each has its own logo–nice!
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