Author: Jonathan Losos Page 30 of 129

From New Scientist:

Kristin Winchell

By Carolyn Beans

City living comes with unique challenges. If you’re a lizard, scaling a windowpane without sliding off is one of them. One lizard has already evolved traits to help it do just that.

“Urban areas are just another environment. The animals that live there aren’t somehow immune to natural selection,” says Kristin Winchell of the University of Massachusetts Boston.

Her team compared males of the anole lizard (Anolis cristatellus) in the Puerto Rican cities of Mayagüez, Ponce and San Juan with those in nearby forests.

They found that city lizards regularly clung to objects like walls and windows, proving that they use the full urban environment instead of restricting themselves to wild patches more similar to their forest roots.

Compared with forest-dwellers, city lizards had longer limbs and more lamellae – scale-like structures that help their toes stick to surfaces. These traits probably enable them to stay attached to slippery urban perches. “I chased a lizard that ran straight up a window 30 feet and was out of reach in 15 seconds,” says Winchell. “I couldn’t catch this well-adapted lizard.”

The team also raised urban and forest lizards from the Mayagüez region in the lab and found that differences in limb length and scale number remained, suggesting a genetic basis to the urban lizards’ abilities.

The anole frequently wows scientists with feats of rapid evolution in natural environments. The new finding suggests that this capacity applies to cities as well.

Other urban animals also adapt. We know, for example, that birds alter calls to be heard over city noise and leafcutter ants adapt to elevated temperatures in an urban heat island.

But well-studied examples are rare. “Urban evolution is a really young field,” says Winchell.

Evolutionary biologist Jason Munshi-South of Fordham University in New York agrees. “There aren’t many documented cases of urban evolution yet, but people are going to start looking for them in earnest,” he says.

Munshi-South believes Winchell’s study is an excellent addition to this emerging field. “The next step,” he says, “which I’m excited to see them do, is to identify the genes underlying these adaptive traits.”

Winchell says that, ultimately, understanding urban adaption could help conservation. “Having a grasp on which animals tolerate urbanisation gives us a better idea of which ones we need to focus on when preserving natural habitats,” she says.

Evolution, DOI: 10.1111/evo.12925

The Dodo provides the full details, but here’s the gist: “I was at the zoo watching the gorilla exhibit [at the San Diego Zoo], and that little lizard came up and just froze when the gorilla started playing with it. He picked it up by the tail a few times, poked at it, but never killed it.”

As Yoel Stuart reported previously in AA‘s pages, Anolis carolinensis has become established at the San Diego Zoo. Who knows which of the zoo’s denizens will be the next to adopt an anole?

and

and this tweet, in turn, refers to this post:

This video, shot by Johann Prescher, is of an Anolis lineatus from Curaçao, gracefully jumping from one tree to another. Note, however, what it does just as it lands, pulling up its forebody to contact the trunk with all four legs simultaneously, like a flying squirrel. The mechanics of jumping in anoles have been well-studied, but the mechanics of their landing, not so much. Good research project waiting to be done!

A letter in Anole Annals’ inbox. Can anyone help?:

I am a student from xxx High School in New York. As a science research student interested in phylogeny of squamata, I have come across Bayesian Inference quite a lot. I have spent a lot of time researching bayes theorem and how it relates to phylogeny, but have yet to find an article that makes sense to me as a sophomore in High School. Do have an explanation to bayesian inference and how it used in phylogenetic research? Being interested in phylogenetics, I have looked into researching phylogenetic relationships of Pogona based on molecular data. I have yet to find a taxonomic revision of Pogona, the latest one I found only used morphological data, Taxonomy of Pogona (Reptilia: Lacertilia: Agamidae) by Witten in 1994. Do you think this would be a good topic for me? In addition to selecting genera to study, I have had trouble understanding the methodology that goes into phylogenetic studies. For the most part the methodology resembles collecting DNA data through PCR, then bayesian analysis is run using MrBayes. Can you explain to me the process of choosing primers for use in PCR? Can you explain what and how data is inputted into MrBayes? Would you or anyone you may know possibly be interested in assisting me with my research in the phylogeny of squamates?

From Skip Lazell’s 1972 monograph

Like many other biodiversity journals, the contents of the Bulletin of the Museum of Comparative Zoology are available on the Biodiversity Heritage Library. However, the BHL can be somewhat cumbersome to deal with, if not downright counterintuitive. Just today, I downloaded Lazell’s spectacular, classic monograph on the Lesser Antillean anoles, full of detailed descriptions, lovely illustrations (as above) and incisive commentary. Every digital library should have a copy, and so here’s your chance to get one easily, by clicking on this link. But note: the link apparently is only good for 30 days (and someone had to try it twice to get it to work, so be persistent). Also note: it’s a big file, so be patient as it downloads.

Enjoy! And after you look it over, write a nice comment for Skip, AA‘s all-time leading commenter, to read.

George Gorman in the field

George Gorman, guru of all things Anolis, writes in:

49 years before Barack Obama’s historic visit to Cuba , I made a historic visit to Cuba but did not visit the Castro brothers, nor was there a baseball game played in my honor. I did, however catch a lot of Anolis,and send a letter to Science about my trip … which was published.”

Read it here.

A recent paper in Science Advances by Daza et al. reported on 12 amber lizard fossils from Myanmar. First author Juan Daza provided an author’s view of the paper two days ago, but I thought I’d add a little more–mostly some cool visuals and links to reporting in the press–here. Particularly notable were a specimen that appears to be on the evolutionary way to becoming a chameleon and gecko with different toepad structures. You can read nice summaries of the articles in the Christian Science Monitor and the BBC.  Anoles even make an appearance in the nifty figure summarizing what we know about fossil amber lizards (more on amber anole fossils).

A common question is whether green anoles (A. carolinensis) and brown anoles (A. sagrei) can interbreed. I am unaware of any hybrids between the two species, and given their long evolutionary separation, it seems unlikely that they could reproduce successfully. Nonetheless, occasional reports of interspecific matings are made, and here’s another.

Mitchell Gazzia posted this photo on his Facebook page, and provided these details:

Took place in late June of 2012 in Melbourne, the Lake Washington area in Brevard County…very close to the intersection of Lake Washington and Turtlemound roads.