Category: All Posts Page 86 of 154

Rapid Evolution to Urban Environment in Puerto Rican Anoles

From New Scientist:

Lizard on reddish wall
Clinging on with ease

Kristin Winchell

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

Anoles of Luquillo, Puerto Rico: ID Help

I did a bit of herping in Luquillo on the northeast coast of Puerto Rico and the abundance of anoles and frogs  was incredible. I was hoping for help IDing these guys and any insight you might have on these species. I think the first three are the same species?

  1. We found this sleeping anole perched up on the back of a sign.

Luquillo

2)    Anole, Luquillo

3)        Luquillo

4)

Luquillo

5) Luquillo

6) This last one was found in the Yunque, not in Luquillo. Not the best photo, but it was a beautiful anole.

anoleYunque

Thanks again!

Gentle Gorilla Befriends Green Anole

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 pagesAnolis 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?

More Anole Related Tweets

tweet2

and

pushups

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

fieldworkfail

Teaching Kids How To Dewlap

Anolis lizards have established their place in the annals of college textbooks. There are also a growing number of resources available for elementary and high school teachers to bring the biology of anoles into their classrooms as well. The Howard Hughes Medical Institute (in collaboration with Jonathan Losos) developed several online modules around anoles: one on the diversity of Anolis lizards, another on speciation, and a virtual lab integrating those topics. Michele Johnson also has several classroom exercises on here website, LizardsandFriends.org, some of which have been discussed on AA previously (here and here). I am writing today to share another exercise with our readers that was a recent success with a group of young scientists-to-be.

Dewlapping fifth graders at GEMS 2016

Dewlapping fifth graders at GEMS 2016

I recently introduced Anolis lizards to a group of fifth and sixth grade students at a conference aimed at getting young girls interested in the STEM professions. With around 130 girls learning about topics ranging from gemstones, programming, seeds, and urban wildlife the event was a undeniable success. My session introduced the diversity of topics that our community addresses with Anolis lizards. After explaining to students how they could figure out what lizards are anoles at the local pet stores (dewlaps and toepads), I used anoles to demonstrate how animals can communicate without talking. My exercise amounts to a game of charades where the students have a dewlap, a display-action-pattern, and a key representing four species from Puerto Rico (thanks to Travis Ingram). The display patterns are not as complex as real dewlap displays, but were made to allow the students to easily act them out and distinguish between the patterns and it worked great. The kids thought this was a lot of fun and it gave me the opportunity to pepper the discussion with additional comments about animal communication. I originally designed the exercise for fourth through seventh graders, but a curious three-year-old played along just as well during one session. I would be happy if other people used this exercise for their own outreach activities. It can be downloaded here.

In closing I will add that the students were impressed by the brown anole I brought with me. I imagine I would have left a more lasting impression if I brought a knight anole. Things to remember for next year.

Lizard Jumping–Watch It Stick the Landing

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!

High School Student Seeks Help Understanding Phylogenetics and Pogona: Help Needed

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?

Anole CT-Scans in the Tweet-o-sphere

tweet

State of Anole Knowledge: Insights from Anole March Madness

WAnole MM16e just wrapped up our Anole March Madness tournament in which we brought to you many fictional battles of mainland and island anoles. We researched each species included in the tournament and highlighted some little-known facts about the participants. We told you about dewlap colors, ecomorphs, habitat use, invasion, body patterns and colors, and much more. But finding this information for each species was more challenging than we originally expected. The state of anole knowledge is certainly imbalanced.

Looking at the number of Google Scholar citations for each species shows just how imbalanced our knowledge of different species of anoles is. Of the species we included, only three of the mainland species had more than 200 citations and none had more than 600. In contrast, of the island species, six had more than 200 citations and Anolis cristatellus had a whopping 1230 citations! Within regions there is quite an imbalance, too — check out how many more studies there are on Central American species compared to South American species (orange and red) and on Greater Antillean species compared to Lesser Antillean species (light and dark blue). This is perhaps unsurprising to many. We all know that anole research tends to be biased towards Caribbean species, but it was surprising to me how large this bias is!

This gives a sense of how much information is available for the species we highlighted in our tournament. For a few species, we were not even able to find photos (at least with appropriate usage rights) and for many the only information we could find was native range, color, and body size. For example, Anolis placidus had only five Google Scholar citations to go by, few images (other than specimens), and really no ecological information other than its ecomorph. But it must be named the “Placid Anole” for a reason, right? So we ran with that. Even with the paucity of information for some species, we were able to piece together some interesting stories highlighting some of the unique adaptations, ecology, and morphology. Here are some of my favorites with links for more information.

Anolis aquaticus and Anolis macrolepis were our two representative aquatic anoles. These species are adapted to streamside living, using the boulders as foraging grounds and for quick escape from predators–swimming, running across water, and even remaining submerged to get away from a threat! We used these behaviors in our stories–allowing both species to have sure footing in their stream side home and escape into the water when necessary.

Another unique anole we featured was Anolis onca, the only anole to have lost its toepads entirely. Anolis onca is adapted to a beachy life, making its home in sandy substrates and perching on bushes. We played this as a strength in round 1. It’s not clear what the functional reason for the loss of lamellae is–as has been suggested on Anole Annals, perhaps the sand renders lamellae or setae useless. The reasons for this morphological outlier are yet to be explored, but we figured A. onca must have an advantage in the sand over other anoles!

Anolis proboscis (photo by Luke Mahler)

Anolis proboscis (photo by Luke Mahler)

 

Of course we had to feature the Anole Annals darlingAnolis proboscis. Here at Anole Annals we’ve covered everything from  babies hatching with tiny horns to discussion of their odd looks to the “rediscovery” of this odd Pinnochio anole. What exactly that horn is for seems to be up for some debate still, but it seems that it is likely involved in sexual selection: male-male competition or female choice. And the part in the battle where the anole wiggles his snout? Yep, they do that!

 

Anolis gorgonae (photo by Luke Mahler)

Anolis gorgonae (photo by Luke Mahler)

A crowd favorite from our tournament, but alas not the champion, was the only completely blue anole: Anolis gorgonae. This anole didn’t make it too far in our tournament because his bright blue body made him extremely visible on the forest floor. The blue may help camouflage them way up in the canopy, but it seems that down low they are visible against the green leaves from a distance. We wanted to root for him too, but how does something that visible not get eaten to extinction?

 

And finally, we made sure to feature a few of the anole kings: the crown giants. We know our readers here at Anole Annals love their giant anoles. These monsters of the canopy seem like they could beat out just about anything (or eat them!), and so it was in our tournament. In the end it was too tough to decide between the beloved Anolis equestris and the lesser-known giant of the mainland, Anolis frenatus.  And so we enlisted the help of the mainland-island competition vs predation debate (reviewed in Losos 2009 – p.159) and had a monkey swoop in to help us decide (yes, this happens!). We wondered, could the predator-naive A. equestris establish itself in a land full of predators like the forests of South America? Despite being successful at invading Miami and some other Caribbean islands, it doesn’t seem to have established itself in South America… yet.

 

On behalf of all of the contributors to Anole March Madness 2016 we thank you for playing along with us. We hope to bring you another tournament next year, so let us know if you want to help make that happen!

Anole March Madness: The Dramatic Conclusion!

Anole MM16

If you missed the live Twitter broadcast of the final round, here it is: the conclusion of Anole March Madness 2016. In the final round, Anolis equestris represented the island anoles and Anolis frenatus represented the mainland anoles to answer the question every anole biologist ponders: are island anoles or mainland anoles superior?

Without any further ado, here’s the final match!

Page 86 of 154

Powered by WordPress & Theme by Anders Norén