Author: Jonathan Losos Page 22 of 129

Liam Revell has developed a method, which he explains in Phytools.

A rose by any other name would still smell as sweet. But what if there’s an anole sleeping inside of it?

Photo by Karen Cusick

Karen Cusick writes on Daffodil’s Photo Blog that she’s never seen anything like this, and neither have I.

Michele Johnson (top) and Manuel Leal (bottom). For more on the Leal lab’s march-related activities, check out the post on Chipojolab.

From the pages of Facebook. Specifically, from Paul Marcellini Photography (check out the beautiful photos on his website). Note that we previously featured another account of a nesting female hummingbird attacking an anole, in this case Anolis stratulus in the Virgin Islands.

here’s a close-up, from Marcellini’s FB page:

Steve Arnold, snake biologist extraordinaire, has a secret love of anoles. Or at least he takes pictures of them on his travels. Here are two anoles from Pico Bonito National Park in northwestern Honduras. Anyone know what they are?

Photo by Barb Karl

Everyone who has studied anoles in the field has had the experience of an anole displaying towards him- or herself. Do anoles actually display to real predators in the field? We’ve even had one AA post reporting a test of that. But there are few observations of such displays. So we were delighted to receive the following note from Barb Karl of Leland, North Carolina:

I was mowing my lawn and was startled by a green lizard that jumped to a nearby tree. I researched what type of lizard it was since we just moved to North Carolina a short while ago and wanted to see what it was.  I found that it was an anole.  I felt bad that I had startled him, so put some live mealworms on the fence as a peace offering.  I checked a little bit later and he was back on the fence, hopefully eating the mealworms.  Then a short distance away a wren appeared in the bird feeder tray.  I watched the anole, he was still on the fence and started going up and down (almost like he was doing pushups and his throat pouch would go in and out). It was like he was trying to make himself bigger so the bird would not want to mess with him.  It was an awesome sight!

I spotted a second Anole on a tree a distance away from the first one.  Can’t wait till they visit again.  Next time I will try and catch a video if it happens again.

Tobias Uller at Lund University is studying phenotypic plasticity in anoles to address the evolutionary significance of such plasticity. He’s interviewed at David Sloan Wilson’s site, This View of Life. The whole interview is interesting, but here’s the snippet on anoles:

One of my projects, with evolutionary developmental biologist Nathalie Feiner, will test if plasticity shaped diversification of Anolis lizards. These lizards are textbook examples of an adaptive radiation because, across the Caribbean, a single species gave rise to multiple species, each locally adapted to a different habitat. We are particularly interested in limb morphology since it is a defining feature of adaptive differences between species; lizards that run around on broad surfaces, such as tree trunks, have longer limbs than those who cling onto twigs, for example.

Anolis equestris. Image used with permission of Tobias Uller.

We already know from work by Jonathan Losos and others that limb growth is plastic in Anolis. What we do not know is if evolutionary diversification of limbs took place through modification of those particular components of bones that respond to mechanical stress during growth – as would be predicted if plasticity ‘took the lead’ in evolution – or if adaptive divergence between species is unrelated to plastic responses within species. To test the concordance between plasticity and evolutionary diversity we rear a lot of lizards from several species on different surfaces and combine this with detailed measures of skeletons of very many species across the entire Anolis group.

We should also remember that plastic responses in some cases can carry over to the next generation. In experiments on water fleas, which have the advantage that they can reproduce clonally so we can rear genetically identical individuals in the lab, we will test the hypothesis that such maternal effects (or non-genetic inheritance) facilitate adaptation to new environments. In some ways, this works just like plasticity within a generation. That is, successful accommodation of environmental stressors enables populations to persist and gives natural selection something useful to work with, thereby providing directionality to evolution.

But here there is another twist that has to do with the evolution of inheritance. As populations adapt, selective removal of costs and negative side-effects should make maternal effects behave like signals, sent from mothers to tell offspring about the environment they are likely to encounter. This process, therefore, describes the evolution of a type of inheritance system.

We cannot study the conversion of an environmentally induced stress response to a detection-based inheritance system in the lab. But we can compare water flea populations that have been exposed to the same stressor, such as metals or toxins, for a different number of generations in the wild. Ultimately, this should give insights into how inheritance systems evolve and how they come to transmit information.

Aposematic warning patterns are supposed to have evolved to warn potential predators to stay away. But do they work? An experimental study at the La Selva Biological Station in Costa tested that hypothesis on common ground anoles, Anolis humilis. Baruch et al., writing in the Journal of Herpetology, presented the anoles with clay models painted in an aposematic or cryptic color. The models were dangled in front of the lizards and wiggled around, simulating a flying insect. Sure enough, the lizards went after the cryptic models nearly half the time, but almost completely ignored the orange and black ones. Aposematic patterns work!