Maybe the classic Darwin evolutionary tree would…
What do you think about the hypothetical case?
Last June, we had a discussion of tail regeneration (that was continued just last week), as part of which I stated that three-tailedness is known in lizards. And sure enough, here’s an example of it, albeit an agamid (at least it starts with “a”). Alan Templeton, of fruit fly and collared lizard fame, is the photographer, and the shot was taken in Kiryat Yam in northern Israel, close to the Mediterranean.
Species, anyone? And, if I’m not mistaken, agamids don’t have tail fracture planes, which explains the lousy looking regenerated tails. But why the triple? Anyone got a photo of an anole doing that? A quick Google failed to find any, but did come up with this.
Last month, we had a trio of papers [1,2,3] on the awesome anolifauna of a tiny park in Miami, which currently hosts five anoles, four introduced from Cuba, Hispaniola and Jamaica, and with a fifth, from Puerto Rico, only blocks a way. Now Janson Jones has joined the chorus, adding his observations from a visit in 2011. Check out his fascinating observations on A. sagrei and the gang on dust tracks on the web.
They say redheads have more fun, but is that true in the brown anole world? We’ve had a lot of discussion of A. sagrei that are overall orangey in color, but less about the coppertop look that seems to pop up in populations far and wide. We certainly see it on some of small Bahamian islands, but not others. The photo above is from Florida, courtesy of Karen Cusick’s Daffodil’s Photo Blog. Who else has seen the redheads, and where? And any idea of their significance?
It’s that time again, time to invite/implore AA readers to contribute posts. All are welcome. Have any interesting questions about anole biology, cool photos? Want to comment on a recent (or not-so-recent) paper of interest? Or tell us about your research plans or results? Anole Annals is a forum for all of these, and anything else anole-related. And now’s a particularly good time, as your trusted correspondent is leaving the country for several weeks. Fear not, there will be reports from the field, but it’s a good time for contributions from any and all! If you’ve never posted before, it’s easy, and instructions can be found here or contact the AA Editorial Offices at email@example.com.
Pat Shipman, AA‘s correspondent in the Little Cayman bureau, reports: “We are very familiar with the individuals of A, maynardi that count our house in Little Cayman as their territory. The individual shown here regularly sleeps on our screen porch in the gap at the top of the door. He is shown in May 2011 in the photo on the left. Judging from the landmarks in the photo, his total length was about 23 cm at that time. Early in Dec. 2012, we saw him again and noticed he had lost his tail. By early February–roughly 2 months–he had regenerated about half of his tail (see photo on right). Judging from reported rates of tail regeneration in A. carolinensis, this is rather fast growth. Of course, warm temperatures accelerate growth and the average temperature here year-round is about 85 degrees (Editor’s note: sure, rub it in). We’re trying to get the photos scaled exactly so we can estimate size & growth better, but this seems remarkable.”
I expect that rates of tail regeneration have been reported in anoles, but I don’t know where off-hand. Anybody know of relevant research? Some googling tells us that tail regeneration was a hot topic in the late 60’s and early 70’s and, in fact, there was a paper entitled “Factors influencing rates of tail regeneration in the lizard Anolis carolinensis” by Maderson and Licht (Experientia Volume 24, Issue 10, pp 1083-1086). Am I too lazy to dig out of the internet? Heck no, but apparently it’s not to be found digitally. Sorry! But wait–it is, only you have to look under the journal’s new name, Cellular and Molecular Life Sciences. In any case, here’s the abstract…oops. There is no abstract. But here’s a section from the beginning of the Discussion: “Our results indicate that temperature may influence at least 3 different aspects of the regenerative process…Comparison of results obtained between 21 and 32 °C indicate that the higher temperature accelerates both rates of blastema formation and subsequent regeneration rates. However, the latter process is seen to be considerably more temperature dependent than the former when Q10 values are compared. Finally, temperature influences the final form of the regenerated tail, a smaller proportion being replaced at the lower temperature.”
And, for Pat, here’s the key figure on tail regrowth:
Who is this Uwe Bartelt, who has ferreted out such a surprisingly large number of anole postage stamps? Well, you can read all about him. Especially if you read German. And if you do, please give us more details. The photos make clear that he’s got a great setup for anole husbandry, with all kinds of cool anoles. Check it out. And translate it!
A while back, we had a post that featured a photo of a male brown anole sticking its leg off the ground and out to the side in an odd manner. Readers speculated that this was to get the body and leg off the hot surface of the ground. AA contributor Miguel Landestoy has sent in a photo of A. cybotes doing more-or-less the same thing, although less awkwardly, and Miguel, too, speculates that this is for thermoregulatory purposes: “the guy may be avoiding the heat on the very reflective surface on the banana/plantain leaf (see that also fingers are also lifted).” This is, of course, reminiscent of the famous dancing behavior of the African lacertid lizard Aporasaura anchietae, which lives in the Kalahari desert and stands on two legs, rhythmically alternating which feet are in contact with the hot sand (check out the remarkable BBC video).
Maybe so, but I’m not convinced. I’ve seen behavior like this many times, and it didn’t necessarily seem to occur in ultra-hot conditions, though maybe I just wasn’t paying enough attention. Thoughts, anyone?
More eye candy for the anole-loving evolutionary biology crowd. This one is a sumptuous photo of A. distichus by inspired photographer and AA contributor Miguel Landestoy, advertising February 2013 Evolution readers to the presence of a paper on dewlap color by Julienne Ng and colleagues, about which we have already reported.
Astute readers will realize that this is the fourth time since mid-2010 that Evolution‘s editors have had the wisdom to put an anole on the cover. Anyone remember seeing a stickleback or cichlid there?
The most recent issue of Herpetological Review (December 2012) includes an article by Ted Townsend, “Proposal to Alter Anole Taxonomy and Ecological Nomenclature.” Townsend does an admirable job of summarizing the issues and, most importantly, includes a shout out to Anole Annals (“an internet forum frequented by anole researchers”). Also notable is the wacky photo that appears to the left of the article (and the left of this text).
Is this a long-tongued anole or an anole-shaped chameleon? And, regardless, can a lizard subsist on a lint-based diet (which would include, I would presume, table crumbs and dead insects)?
For 50 years, scientists have been cataloguing the relationship between area of islands or other patches of habitat and the number of species they contain. In general, the bigger the area, the greater the number of species. In recent years with the rise of interest in incorporating a phylogenetic perspective to all manner of questions, some have wondered how the phylogenetic variety (the degree of relatedness among species) changes with area. In an important new paper, Helmus and Ives take a theoretical perspective to understand what the expectation is for the relationship between phylogenetic diversity and area. Most excitingly, they illustrate their method using data from anoles on Caribbean islands.
Here’s how they describe what they’ve found: “While there was a strong relationship between Anolis species richness and Caribbean island bank area (Fig.3A; Losos 1996, Losos and Schluter 2000), we found no overall relationship between Anolis phylogenetic diversity and island bank area (Fig. 3B) …The greatest variation in phylogenetic diversity was associated with the overall level of in situ speciation … [T]here is a strong PDAR for the seven Caribbean island banks with at least one in situ speciation event (Fig. 4A). The estimated phylogenetic diversity values of these seven banks are dominated by in situ speciation as opposed to among-island allopatric events (Cuba had 2, 47, 49 colonizations, in situ events, species richness, respectively; Hispaniola had 4, 33, 37; Puerto Rico had 3, 11, 14; Jamaica had 1, 5, 6; Guadeloupe had 1, 3, 4; Grenada had 1, 1, 2; and St. Vincent had 1, 1, 2). The strong Anolis SAR causes a strong positive PDAR for these banks because species richness and the number of in situ speciation events positively correlate (Figs. 3A and 4B). If island assemblages were only derived from in situ speciation, then, according to the neutral macroevolutionary model we used, phylogenetic diversity is expected to positively increase, and then plateau with the number of in situ speciation events (Fig. 4C), which is the same relationship we found for the seven island banks (Fig. 4B). On at least the four Greater Antilles islands, island area sets a limit to the number of Anolis species that can arise via in situ speciation (Rabosky and Glor 2010). Thus, when there are no external colonizations that add large amounts of external evolutionary history to island assemblages, positive PDARs are expected.
It is the balance of ancestral colonizations to in situ speciation, therefore, that affects regional phylogenetic diversity. This balance is thought to be determined by a race between colonists, where initial colonist species will diversify if another colonist species does not arrive and establish too soon after the initial colonization event (Gillespie 2004). For Anolis, this balance is related to island area, the timing of island emergence and species diversification, and island isolation (Losos 2009). For example, the largest island bank, Cuba, is the center of Caribbean Anolis diversity and was likely colonized twice, by the ancestor of most Caribbean Anolis, and possibly to all Anolis (Nicholson et al. 2005), and more recently by a colonist species from Hispaniola, whose ancestor was originally Cuban (Mahler et al. 2010). Cuba thus contains a large amount of phylogenetic diversity, not because it has received outside colonists, but because it is large in area and contains old diverse lineages that have arisen via in situ speciation. Small and spatially isolated banks such as those in the lower Lesser Antilles (e.g., Grenada) have had few ancestral colonizations and few in situ speciation events that together result in low phylogenetic diversity. In contrast, species assemblages on small and non-isolated banks (e.g., the Acklins bank of the Bahamas) are completely derived from among-island colonization’s, and thus, have high phylogenetic diversity similar to the Cuban bank (Fig. 3B). Macroevolutionary simulations should thus be extended to include these isolation effects. However, the model and the Anolis data suggest that, in general, PDARs should be flat for oceanic islands whose species assemblages are an outcome of both in situ speciation and multiple colonizations.”
Firstly, let me start by offering my sincere apologies for the standard of photography you are about to view. As you AA readers have become accustomed to Jonathan’s flowing prose, and other members’ excellent use of modern photographic equipment, I must warn you not to expect either here!
As has been mentioned previously, the IBS Conference was a tremendous success, and firstly huge congratulations must be passed on to (a potential anologist in the making?) Ken Feeley for all the hard work and effort. The lack of talks concerning arguably one of the world’s most studied vertebrate biogeographic systems did not detract from the high levels of anole hunting that ensued over the course of the conference!
After a wonderful afternoon visiting Miami’s most bizarre lizard community, the following day provided an opportunity for conversations to be followed up from the previous night’s conference dinner (as some graduate students’ memories may have appeared a little hazy on Saturday morning). Much of the day was spent wandering around FIU’s Biscayne Bay Campus eagerly trying to find the dozen knight anoles that were promised to us the previous night by resident expert, and thoroughly nice guy, Sean Giery.
Sean has spent the past 3 years observing the A. equestris community on this campus, and has assured me that he will bless AA readers with a synopsis of his eagerly awaited dietary analysis paper in the near future. The day started brightly, with two juveniles being found in close proximity to each other; however with just he and I as the only observers, it was tough to include these individuals in the promised dozen.
At the start of lunch, and confronting the midday heat with the enthusiasm of schoolboys on a day trip, we regrouped with some extra eyes and headed back out to continue on our quest. Although A. sagrei, A. carolinensis and A. distichus were abundant, these were still not the target species. A loud thump behind us saw us all swivel in synchrony, like a troop of sunburnt and slightly dehydrated Michael Flatley fanatics, to be confronted by a rather startled green iguana that had just plummeted 10 feet after submissively losing a dispute to a larger male. The campus had previously been awash with a healthy population of green iguanas; however the big freeze of 2009 reduced this significantly so that the only survivors were those small enough to retreat underground. Continue reading
In the era of Big Data, we can ask questions that would have been inconceivable just a few years ago. Consider the types of questions we can ask using Google’s Ngram Viewer, which uses full-text searches of >4% of all books ever printed to characterize relative word or phrase usage over time (this approach was initially described in a 2011 Science paper about “Quantitative analysis of culture using millions of digitized books“).
Among the most important questions one might ask with the Ngram Viewer is “What is the most written-about lizard genus?” I did some preliminary scouting to assess the relative usage of some of the lizard genera that I guessed would be the most popular. I quickly narrowed my queries to the five taxa – Anolis, Sceloporus, Varanus, Lacerta, and Gekko – that I think give the most interesting graphs for discussion. I excluded other potentially popular genera from my queries for for a few reasons. Iguana is very popular, but I eliminated it because it is often used colloquially to refer to lizards that don’t necessarily belong to the genus Iguana. Eumeces never appears as frequently as the other genera in my searches. Pogona is immensely popular as a pet, but usage of this genus name is still far below the others in my list.
Lacerta jumps out to a big early lead and maintains a strong lead throughout the 19th century, thanks to its widespread use in Latin-language literature from the 19th century and countless books about the European fauna (Ngrams Viewer even provides links to the books or articles containing the phrase of interest!).
In the early 20th century, Anolis joins the competition as one of the most popular lizard genera, and opens up a sizeable lead by the 1980s that it maintains until the turn of the 20th century. Although Anolis is briefly surpassed by Varanus in the 2000s, it nudges back into the lead by the end of 2008!
There you have it folks, quantitative proof of the popularity of Anolis! Have I failed to consider some genera that might be competing with Anolis in the lizard genus popularity contest?
Caribnature.org contains a series of video essays about nature, the environment and exploration in Haiti, based on fieldwork led by Blair Hedges at Penn State University. The video above gives details on a trip to a never before scientifically explored mountain range in southern Haiti where the Haitian giant twig anole, A. darlingtoni, was rediscovered 25 years after it was last seen. In addition, a number of new species of frogs were discovered. The mountain chain still contains forest and wildlife because it is far from roads and people, and thus has not been completely deforested. To get there, Hedge’s team were dropped off by a helicopter.
The website also contains links to other useful information about Haiti, as well as a beautiful poster of Haitian biodiversity, which can be requested.
The side-blotched lizard, Uta stansburiana, is one of the most widely-studied lizard species, thanks largely to work by Barry Sinervo and colleagues on the evolution of alternative mating strategies (a.k.a. the rock-paper-scissors game in lizards). The most recent report on the evolution of this interesting species investigates reproductive isolation between two populations of Uta that diverged within the last 22,500 years. One of these populations is found on lava flows and the others if found off the lava flows. This report by Corl et al. (2012) is noteworthy because recent work on a range of other organisms suggests that some “rules” for the evolution of reproductive isolation are shared across the tree of life. Do these rules also apply to lizards?
To my knowledge, patterns of reproductive isolation have only been investigated experimentally in one other genus of lizards: Lacerta (Rykena 1991, 1996; Olsson et al. 2004). This work with Lacerta suggest substantial intrinsic reproductive isolation between species resulting from low fertility and high rates of developmental defects in hybrid crosses. Studies of Lacerta also support Haldane’s Rule because females hybrids (ZW) suffer more fitness consequences than male hybrids (ZZ).
By conducting experimental hybridization studies between these two populations of Uta, Corl et al. (2012) were able to show that significant reproductive isolation has evolved between populations, largely in the form of pre-zygotic post-mating isolation; inter-population crosses produce significantly more unfertilized than fertilized eggs relative to intra-population crosses. Corl et al.’s results are also consistent with at least one general rule for the evolution of reproductive isolation that has been reported in other organisms; asymmetric reproductive of isolation between the two Uta populations is consistent with Darwin’s Corollary to Haldane’s Rule.
How does all this relate to anoles? My lab is interested in this work because we’re in the midst of a major project designed to answer questions about intrinsic reproductive isolation in Anolis. Anthony Geneva reported on some preliminary results of this work earlier this year and we hope to have more to report sometime in the near future.
Rykena, S. 1991. Hybridization experiments as tests for species boundaries in the genus Lacerta sensu stricto. Mitteilungen aus dem Zoologischen Museum Berlin 67:55–68.
Rykena, S. 1996. Experimental interspecific hybridization in the genus Lacerta. Israel Journal of Zoology 42:171–184.
Not quite sure what to make of this, so I thought I’d throw it out to the AA readership. Almost a year and a half ago, I wrote several posts about a field expedition to Ecuador to study the phenacosaur, A. orcesi. Recently, the blog Ponderingspawn.com posted this: “Poonam absolutely delighted me with his poem: This poem is inspired by the traalivs of searching for the elusive Phenacosaurus orcesi during a trip to Baeza, Ecuador last summer:The phenacosaur awakens from dreams of juicy prey,The volcano Antisana shines brightly in the day.Perched on a twig, he rests safely assured,“Those silly humans don’t know what they’re looking for!”Skirting the road edges with trucks whizzing by,No lizards in sight, oh! how time doth fly.Binoculars in hand and scanning the brush,The orcesi are hidden in the leaves so lush.The day slips by till the moon rises high,The time for finding an orcesi is nigh.Alack! Alas! A lizard in sight!But it’s only A. fitchii, try as we might.
Ah yes, the elusive Phenacosaurus Orcesi. I know it well, having once made battle with the beast in the depraved depths of an Irish glen (Pheancosaurus can only live in depravity, so therefore the glen must have been depraved, yay logic!). And now two times are nigh, that of Jesus and of finding the elusive (and depraved) Orcesi. Perhaps there is a connection?”
Get all the details in the newly posted paper by Eckalbar et al. in BMC Genomics “Genome reannotation of the lizard Anolis carolinensis based on 14 adult and embryonic deep transcriptions,” just posted on BMC Genomics. Here’s the low-down: “The green anole lizard, Anolis carolinensis, is a key species for both laboratory and field-based studies of evolutionary genetics, development, neurobiology, physiology, behavior, and ecology. As the first non-avian reptilian genome sequenced, A. carolinensis is also a prime reptilian model for comparison with other vertebrate genomes. The public databases of Ensembl and NCBI have provided a first generation gene annotation of the anole genome that relies primarily on sequence conservation with related species. A second generation annotation based on tissue-specific transcriptomes would provide a valuable resource for molecular studies. Here we provide an annotation of the A. carolinensis genome based on de novo assembly of deep transcriptomes of 14 adult and embryonic tissues. This revised annotation describes 59,373 transcripts, compared to 16,533 and 18,939 currently for Ensembl and NCBI, and 22,962 predicted protein-coding genes. A key improvement in this revised annotation is coverage of untranslated region (UTR) sequences, with 79% and 59% of transcripts containing 5′ and 3′ UTRs, respectively. Gaps in genome sequence from the current A. carolinensis build (Anocar2.0) are highlighted by our identification of 16,542 unmapped transcripts, representing 6,695 orthologues, with less than 70% genomic coverage. Incorporation of tissue-specific transcriptome sequence into the A. carolinensis genome annotation has markedly improved its utility for comparative and functional studies. Increased UTR coverage allows for more accurate predicted protein sequence and regulatory analysis. This revised annotation also provides an atlas of gene expression specific to adult and embryonic tissues.”
Every now and then we’ve had posts on this blog about non-anole lizards with anole-like dewlaps (e.g. 1, 2). Many agamids have flaps of skin under their throats that begin to resemble a dewlap, but male lizards in the South Asian genera Sitana and Otocryptis have the most “anoline” dewlaps I’ve seen so far. Indeed, some readers were almost fooled by Sitana’s resemblance, in both dewlap and dorsal patterning, to anoles. I spent the summer of 2012 documenting aspects of the display behaviour, morphology, and ecology of Sitana–here are some of my findings
Despite its ubiquity across much of peninsular India and Sri Lanka, Sitana remains relatively unstudied. Individuals across much of the range are classified as a single species, Sitana ponticeriana, despite substantial variation in dewlap morphology. It turns out that there are at least three dewlap variants, which occur, for the most part, in allopatry. Note the gradation in dewlap colouration between the three “morphs.”
For those people who like to watch videos of yule logs burning in a fireplace, the tropical equivalent is this video of Puerto Rican anoles displaying. It features cristatellus, evermanni, pulchellus, krugi, stratulus and gundlachi. A second video on the Fleishman Channel has more displays. And the nice tropical bird soundtrack is very relaxing.