All posts by Adam Algar

About Adam Algar

Associate Professor at the University of Nottingham (UK). My research focuses on niche limits and dynamics across scales, from individual organisms to the globe. Mostly lizards.

The Contronymic Effect of Behaviour on Evolution: Does Behaviour Promote or Retard Evolutionary Change?

Anolis shrevei on a rock. Photo courtesy of Katharina Wollenberg Valero.

Anolis shrevei on a rock. Photo courtesy of Katharina Wollenberg Valero.

Back when I was an undergrad, we were given the impression that animal behaviour and ecology (and evolution for that matter) were distinct disciplines. ‘Behaviour’ had its own classes, professors, and students, mostly separate from the ecologists. The disciplines also have their own, aptly named, journals: Animal Behaviour vs. Ecology. Of course, even then we knew that this division wasn’t a hard boundary and journals like The American Naturalist explicitly included ecology, behaviour and evolution, but we still didn’t think of these disciplines as inseparable. The impression seems to have stuck because fast forward 15 years and I was recently surprised when a colleague, upon hearing about our work on microhabitat use in agamids said, “I didn’t know you did behaviour.” Well, until that moment, I didn’t know I did either! I simply hadn’t thought about what we were doing in that way. Upon reflection, it should have been obvious, just like it should have been obvious that the behaviour/ecology distinction was a false one. I have no idea how widespread my once-perceived separation of ecology and behaviour is, but the fact that there’s a need for a journal, Behavioural Ecology, that specifically merges them suggests they’re still not perfectly integrated.

So why natter on about behaviour, ecology and evolution? Because a recent paper by Martha Muñoz and Jonathan Losos, published in The American Naturalist, is a fine example of why these shouldn’t be separated. Muñoz and Losos set up a dichotomy of hypotheses about how behaviour influences evolution: on the one hand, exploratory behaviour can expose species to novel selection pressures, stimulating evolution, but on the other, behavioural fidelity could shield species from those same selection pressures, ‘forestalling’ evolution. So, which is it? Well—spoiler alert—it’s both. So long nice dichotomy. To reach their findings, the authors looked at thermoregulatory behaviour and how it affects adaptation to high elevation habitats in the Anolis cybotes species group (specifically cybotes, armouri and shrevei). They found that, despite much cooler temperatures at higher elevations, high and low elevation species had selected temperatures in the lab and maintained similar body temperatures in the field, via increased thermoregulation at high elevations. Thus, despite the cooler temperatures, anoles hadn’t evolved to prefer colder temperatures on mountaintops. So behaviour halts evolution, right? Yes but no. To thermoregulate so extensively, anoles had to seek out warmer microhabitats, specifically boulders. And we know what happens when anoles change their perch type: evolution! Muñoz and Losos found that shrevei and armouri had flatter skulls, consistent with life on the rocks, as well as shorter hind limbs (but no differences in toe length or lamellae number). The evolutionary basis of the morphological change in head and femur traits was confirmed by a common garden. Nifty.

Effects of behavioral thermoregulation on evolution of high elevation anoles. On the left, thermal environment, body temperature and lab-selected-temperature of low and high elevation anoles. On the right, morphology of high and low elevation anoles in the field and in a common garden. Modified from Figs 1 and 2 in Muñoz and Losos (2017).

Effects of behavioral thermoregulation on evolution of high elevation anoles. On the left, thermal environment, body temperature and lab-selected-temperature of low and high elevation anoles. On the right, morphology of high and low elevation anoles in the field and in a common garden. Modified from Figs 1 and 2 in Muñoz and Losos (2018).

The overall message of the paper is clear: the same behaviour inhibited evolution along one niche axis and promoted it along another. Muñoz and Losos argue that the lack of evolutionary change in thermal traits arises from the Bogert effect, where behaviour limits exposure to novel selection pressures. However, there is a chance that the lack of evolution could be due to other constraints, like a lack of genetic variation. Testing this would require an experiment with a control group of lizards that couldn’t behaviourally avoid thermal selection pressures. A previous paper by Muñoz, Losos and others, provided just such a natural experiment. In that study, Muñoz et al. found that lower CTmin has evolved in high elevation cybotoids, relative to low elevation ones. Why? Because at night, when its coldest, anoles are unable to behaviourally thermoregulate to avoid the cold –voilà, a control where the Bogert effect was negated. And once behaviour was removed from the equation? Evolution! This finding adds even more weight to the role of behaviour in inhibiting the evolution of thermal traits in this system. Cool stuff (I make no apologies for that pun).

There’s lots more in the Muñoz and Losos paper than I touched on here so give it a thorough read. It goes a long way to destroying any divisions that might still exist between behaviour, ecology and evolution and it makes a strong case for why we need to consider multiple niche dimensions when we talk about niche evolution and conservatism. Plus, it gave me an excuse to use the word ‘contronymic.’

Muñoz, M.M. & Losos, J.B. 2018. Thermoregulatory behavior simultaneously promotes and forestalls evolution in a tropical lizard. The American Naturalist. DOI:10.1086/694779.

Video of Running Trunk-Ground Anole Needed

I’m looking for a bit of help and where else to turn than the dedicated readers of Anole Annals? Does anyone have a short video clip (ca. 10 seconds) of a trunk-ground anole running on either the ground or a trunk that they’d be willing to share? I’d like to use it for a couple of upcoming talks, and for teaching. Proper credit would, of course, be given. Plus I’ll buy you a beer if you ever happen to be in Nottingham. I’ve got a few short clips of sagrei but unfortunately the frame rate went screwy when I tried to convert them, hence the appeal. The point is to contrast a trunk-ground’s movement with this clip of carolinensis (shot by Leslie Bode on the Anhinga Trail, Everglades, FL):

If you have something suitable that you’re willing to share, please either leave a comment, or you can email or tweet me (adam.algar[at]nottingham.ac.uk, @acalgar).

Thanks!

Globalization and the 50-Year-Old Predicted Reorganization of Anole Biogeography

helmus_etal_fig2I caught an anole lizard and tossed it ten feet or so out into the water. To my dismay, it popped to the surface, swam expertly back to the shelter of the trees, and climbed up a mangrove trunk. Well, I continued, suppose a full hurricane blew an anole so far away on open water it couldn’t get back. Our little experiment shows that it could swim to the nearest islet if it were not too far away.

So wrote E.O. Wilson (1995 p. 271, Warner Books, NY) in his autobiography, Naturalist, reflecting on his island defaunation work with Daniel Simberloff. From his ‘little experiment’ (I can hear animal care committees cringing), Wilson postulated that anoles could, if they had to, disperse from island to island across open water. Whether anoles can cross water, however, isn’t that important. Rather, what’s important is that they rarely do. Anoles’ status as a symbol of island biogeography and adaptive radiation is largely due to the fact that isolation and the resulting low gene flow among islands set the stage for in situ speciation and adaptive radiation. In fact, much of what we (and island biogeography in general) owe to anoles, we owe because they don’t swim so well. And they don’t colonize new islands very often.

Or rather, they didn’t.

A new paper in Nature by Matt Helmus, with AA stalwarts Luke Mahler and Jonathan Losos, shows how human-mediated dispersal of anoles among Caribbean islands is reorganizing anole biogeography in a very predictable way. I suspect many who have worked on anole island biogeography, me included, have considered what to do about recent introductions and have often, like me, dropped them out of a dateset with the goal of trying to discern the ‘natural’ pattern. Helmus et al., however, saw the spate of recent anole introductions across the Caribbean as an opportunity, rather than a nuisance. Their great leap came from realizing that this reorganization of anole Caribbean biogeography should be predictable from the basic tenets of island biogeography theory.

Based on MacArthur and Wilson’s equilibrium theory, adaptive radiation theory and drawing on Losos and colleagues’ past work from 1993 and 2000, Helmus et al. predicted three patterns: 1) Species-impoverished islands (for their size) should have more exotics than more saturated islands, 2) The phylogenetic diversity of islands should increase due to exotic establishment, and 3) Human-mediated introductions should degrade richness–(geographic) isolation relationships. In short, they found evidence consistent with all of these patterns. Furthermore, they showed that economics that has replaced distance as the key determinant of island isolation. Needless to say, these are very exciting results that have supplied a key test, at biogeographic scales, of some classic theory*. It’s a must read.

This paper is also important because it shows how ‘blue skies’, curiosity-driven science can help us understand and, most importantly, predict how human activity will impact ecological systems. Did MacArthur and Wilson know, more than half a century ago, that their work would predict how increasing globalization and trade embargoes would affect modern biodiversity? I doubt it (cue someone pointing out in the Comments the exact line in the ETIB where they do predict this). However, regardless of whether they knew it at the time, this is exactly what their theory has done. As Helmus et al. state (p. 545): “Our results support the theory that it is the influence of geographic area and isolation on … speciation and colonization that fundamentally determine island biodiversity”. However, as they crucially find, what we now need to do is rethink how we define ‘isolation’. We can’t leave ourselves out of the equation any more. It’s economics, not geography, that matters now. Thus, not only does Helmus et al.’s paper test a long-standing theory, but it provides a clear example of the importance of fundamental scientific theory for understanding and predicting ecological dynamics in the ‘Anthropocene’.

In conclusion, the observation that humans are moving anoles — and other taxa — around faster than they could make their own way will come as a surprise to no one. But finding that the subsequent reorganization of life can be predicted by island biogeographic theory is fantastic (it should be pretty clear by this point that I like this paper. A lot). So if you haven’t read the paper, you should. I know it’s a terrible cliché to call a study ‘elegant’. So I won’t. I’ll call it damn elegant.

*I can’t help but mention that Helmus et al.’s findings were mostly based on good old-fashion OLS regression and ANOVA, and visualized using simple scatterplots – No fancy-shmancy statistical machismo here (phylogenetics aside). Just a clear set of predictions that could be parsimoniously tested. Chapeau.

Editor’s note #1: nice summaries of this paper have been written by Ed Yong’s Phenomena: Not Exactly Rocket Science blog and by Emily Singer in the new online Science magazine Quanta.

Editor’s note #2: The paper grabbed the cover of Nature.

Helmus et al. cover

This, in turn, joins a long list of recent science journal covers sporting an anole:

covers

When the Going Gets Cold, Anoles Get Colder

CTmax, Tb, and CTmin of cybotoid anoles & env. temperature. Modified from Fig 2 in Muñoz et al.

CTmax, Tb, and CTmin of cybotoid anoles & env. temperature. Modified from Fig 2 in Muñoz et al.

AA contributor Martha Muñoz’s work on altitudinal variation in the cybotoid anoles has already netted her the Raymond B. Huey award and of course, been featured on AA. A big chunk of this work, co-first authored with Maureen Stimola, has just been published by the Proceedings of the Royal Society B. If you haven’t read it yet, check it out.

I love this paper. However, in the spirit of full disclosure, I’m completely biased as I happen of be one of the co-authors. But I’m sure I’d love it anyway. Why? In part because it tests a clear hypothesis using multiple lines of evidence and eliminates confounding explanations – characteristics every paper should have. It also has cool (or should I say hot?) results. However, more than this, I think this paper demonstrates the power of combining good ole’ fashioned (yet cutting edge) field work with macroecological and macroevolutionary models, demonstrating how these different approaches can really complement each other.

What did Muñoz and company find? Briefly, they looked at hot and cold tolerance (CTmax and CTmin) of six species of cybotoid anoles on Hispaniola, in relation to elevation. They found far more variation in CTmin than CTmax across species (and populations). By bringing in a little macroecology, they showed that CTmax isn’t correlated with environmental temperature, but CTmin is, i.e. when the going gets cold, the anoles get colder – sort of. The catch is that while CTmin strongly tracks temperature, daytime body temperature does not. This is a neat result in and of itself and fits well with a big, recent, data-mining paper showing similar trends across hundreds of both ecto- and endothermic species. But while it doesn’t have the breadth of that paper, Muñoz et al. were able to go further. Firstly, bringing in a little macroevolutionary analysis, they showed that yes, CTmin has actually evolved significantly faster than CTmax. Neat, but at this point you should be asking yourself, “What about acclimatization?” and “Is this just plasticity?” Muñoz et al. asked the same thing and headed back to the field. A lot of work later and the answer was no. An acclimation experiment rejected this possibility.

At this stage, most macroecological and macroevolutionary analyses would have to stop at the identification of a clear, and intriguing pattern of fast past evolution of cold tolerance along an elevation gradient, but little CTmax evolution. The Discussion of such a paper would suggest potential hypotheses to explain the pattern and that would be that. But Muñoz et al. again went further and, by working in the field to measure perch use and operative temperatures, worked out why . The key result showed that lizards can behaviourally thermoregulate to escape the heat, thus reducing selection on heat tolerance, i.e. the Bogert effect. However, the nighttime cold cannot be escaped (actually, it can, by moving to England where it hasn’t dipped below -2 deg C this winter. Enjoy that polar vortex America!), leading to selection on cold tolerance.

Like I said, very cool results and a real testament to the power of using field experiments and macroevolutionary models to inform each other and go beyond what each approach could do in isolation. So please read it, challenge it, and build on it.

The Anole Effect In Taxonomic Research Bias

Everyone (who reads this blog) knows that anoles are one of the most fascinating groups of organisms on the planet. We also all know that this makes them a remarkably popular lizard genus to study, a topic that Rich Glor has addressed on this blog previously. However, while dominant in some fields (and meetings, like Evolution or SICB) anoles scarcely make an appearance at others (ESA, IBS). This raises the question of whether anoles are really as popular as we think? How do they stack up to other sexy taxonomic groups like mammals, birds or bees?

A recent tweet and blog post by Chris Buddle from McGill gives the basis for an answer. He used a (quick and dirty) Web of Science search to find the number of publications per species within 15 haphazardly chosen Orders, merging these into higher taxonomic groups for visual comparison:

Buddle showed that research publications are strongly biased toward mammals (no surprise there), then herps, then birds (I admit, a priori, I thought 2nd and 3rd would be reversed). However, the obvious question which jumped to my mind (and, I’m sure, to yours) was: how do our favourite dewlapping demons compare? A quick search on Web of Science with search string ‘Anole OR Anolis’ (yes I could have gone with anol*, but this picked up a few thousand extra hits for anolyte) gave approximately 12,686 hits. Using The Reptile Database‘s number of 393 anole species (cue argument now), I roughly mapped the anole results on to Buddle’s plot:

Modified from: www.scilogs.com/expiscor/biodiversity-bias-the-relationship-between-taxon-diversity-and-research-publications

Modified from: www.scilogs.com/expiscor/biodiversity-bias-the-relationship-between-taxon-diversity-and-research-publications

Anoles win! Perhaps not surprisingly, anoles are remarkably well studied given their diversity, at least compared to other groups defined at the Order level (keep in mind that, because publication intensity is uneven within taxa, averaging across a more diverse group will tend lower the numbers). Nonetheless, anoles annihilate the carnivores, which Buddle highlights as the most studied order with a publication to species ratio of 7. However, let’s not forget that the vast majority of these studies are on sagrei or carolinensis, so there are still hundreds of under-studied anoles (and really, can a species be over-studied?)

Lastly, before we get too smug about the popularity of our exalted study genus, with its publication to species ratio (pub:spp) of 32.3, I did a quick look at the numbers for the genus Parus. This genus (even after lumping it in with Poecile, Cyanistes, Lophophanes, and Periparus) had a pub:spp = 327.1. And within the herps? Well, Sceloporus clocks in at 85.7. And Xenopus‘ pub:spp is 12451.3! Of course, Xenopus’ ratio is heavily influenced by biomedical research. Also, as I mentioned above, the uneven study of species within genera means averaging over a diverse genus like anoles will drag down the ratio, compared to less diverse genera like Parus, Sceloporus, or Xenopus. Even so, while anoles are clearly very popular, we undoubtedly still have a lot of work still to do.

WTF Anole Evolution?


The website WTF Evolution has been popping up around the ecology and evolution blogosphere lately. It was recently featured by Jerry Coyne at Why Evolution is True and by Jeremy Fox at Dynamic Ecology. However, if you don’t read either of these blogs, or haven’t heard about the site, I suggest having a look – it’s pretty funny (especially ‘Fiddler crab’). Best of all, however, is that anoles are featured (and they’re the only organism to get a video)! The example is one featured on Anole Annals previously and is from a study by Casey Gilman in Duncan Irschick’s lab. The video shows that when anoles jump from springy perches, the recoiling perch can hit them in the tail, throwing them off balance. As the captionist at WTF Evolution notes, not a great thing for a lizard that spends a lot of time on branches: “Great work, Evolution“.

 

IBS Update: Sub-Fossil Anoles on Anguilla

Hello once again from the IBS in Miami. As I mentioned in my last post, anole presentations are a little thin on the ground here (though not around the conference centre where, with the help from some locals, we saw sagrei, carolinensis, equestris and distichus today).

I did have the opportunity yesterday to check out the the second of two anole presentations here – a new look at the sub-fossil lizard communities, with a focus on a question familiar to many readers of this blog: What’s the deal with A. pogus on Anguilla?

Has A. pogus ever been on Anguilla? Nope.

The study is being led by Melissa Kemp, from Liz Hadly’s lab at Stanford. Melissa has re-analyzed lizard dentaries from excavations on Anguilla that featured heavily in an anole character displacement versus taxon cycle debate in the early 90s.

By analyzing the size distribution of anole dentaries dating back 10,000 years on Anguilla, Melissa argues that not only is there a lack of evidence for a taxon-cycle involving A. pogus, but that there’s no evidence that A. pogus has occurred (in meaningful numbers) on the island at all! To further test this, Melissa has sequenced a portion of cytochrome b for five specimens thus far, all of which have turned out to be A. gingivinus, with more sequences coming down the pipeline.

Anoles aren’t the only lizards Melissa has uncovered – with Thecadactylus, Ameiva and Leiocephalus all present. Anoles have dominated the fauna in all but the earliest (and sparsely sampled) time slice and Leiocephalus was historically present (but probably not abundant) but disappeared several thousand of years ago and has not reappeared in the sub-fossil record since.

This was my first exposure to sub-fossil analysis of lizard communities and I was definitely impressed. I don’t have a sense of how much similar work there is in the literature (but I’m sure readers of the blog can educate me), but there seems substantial scope to collaborate with zoo-archaeologists to get more specimens and data on past trait variation and anole assemblage composition.

Where Are The Anoles?

Missing anoles? Or missing anole biogeographers?

As you may (or may not) know, the 6th meeting of the International Biogeography Society (IBS) is underway in Miami, FL.

So here I am, in the anole invasion capital of the world, with the Caribbean on the doorstep, and a look through the conference program reveals a paltry TWO talks on our favourite lizards. Contrast this with Martha Munoz’s reports from SICB, with 18 (or so) anole talks. Of course, there’s something to be said for quality over quantity and the two anole presentations here do a good job of flying the flag. Yesterday Jonathan Losos kicked off one of the symposia with a talk on anole traits, function and biogeography (with a smashing blue / yellow colour scheme), and later today I’ll be searching out a poster on anole fossil assemblages (post forthcoming)

Nonetheless, I still can’t help wonder, where are the anole biogeographers? You can’t look through a text on island biogeography, species area curves or adaptive radiation without finding a dewlap. So the question is, are people not doing anole biogeography anymore? This isn’t the case, so it can only be that either the IBS isn’t on the radar, or people choose not to go. Either way, you’re missing out on a great meeting – it’s an excellent opportunity for the anole research community to radiate and reach a slightly different audience.

Novel Environments: The ‘Fancy Dress’ Party

Anole masks. Note: The dewlaps looked a lot pinker under natural light!

Organisms that colonize a new landmass are often faced with strange environments and selection pressures. Biologists are no exception. Having quasi-recently emigrated to England, I can tell you that, from a North American perspective, the UK can be pretty strange. One of the novelties, along with saying ‘Ta’ and not heating buildings, is the ‘fancy dress’ party. If you’re American or Canadian, then ‘fancy dress’ probably conjures images of black tie, tails and sherry (Downton Abbey anyone?). But no. ‘Fancy Dress’ is when otherwise regular people don ridiculous costumes and drink a lot (wait, that does sound like Downton Abbey). The reasons behind this custom (the dressing up, not the drinking) are unknown to me. Maybe it’s because there’s no Halloween and thus no annual outlet for looking like an idiot?

Anyway, the point is that this year, our departmental party’s theme was Noah’s Ark. Of course, this left us with only one option. If the world’s going to flood, then we’d better be sure there’s a pair of anoles on board. After all, think of the opportunity for radiation when the waters recede. All it took was a little duct tape, papier-mâché, paint, an artistic spouse and voila, Anolis masks! Of course, I can’t believe that I’m the only one who has ever attempted an anole costume – anyone else have any pics to share of their efforts?

Feeling isolated? New Research by Wang et al. Shows You’re Not The Only Anole Feeling That Way

Proportion of population genetic divergence accounted for by isolation-by-environment and isolation-by-distance in 17 Anolis species (from Wang et al.)

Identifying the factors contributing to population genetic divergence is important for understanding how many evolutionary processes play out in geographical space. Plus, it’s just plain interesting. In a new paper in Ecology Letters, Ian Wang, with Anole Annals stalwarts Rich Glor and Jonathan Losos, tested the roles of environment and distance in determining spatial patterns of population genetic divergence of 17 anole species on the Greater Antilles. To give the game away (spoiler alert!), the short answer is that both play a role, with some interesting variations among islands and species. However, it’s not just Wang et al.’s results that are interesting (more on those later), but also how they went about getting them.

Wang et al. tested two (not mutually exclusive) hypotheses for population genetic divergence. The first was isolation-by-distance (IBD), where distance and dispersal barriers prevent gene flow among populations. The second was isolation-by-environment (IBE), where there is either selection against dispersers, or a preference to remain in the environment where individuals are locally adapted. To test these hypotheses for each species, the authors first quantified environmental dissimilarity among populations using the Worldclim dataset, MODIS vegetation data, and elevation. Next they measured geographic distances among populations, but with a twist. To incorporate the idea that certain environments will be easier to disperse through than others, Wang et al. constructed environmental niche models. They then used the resulting (reverse) suitability values as a proxy for the ‘resistance’ of an area to movement and calculated the weighted distance between populations using two methods: least-cost pathway and all-possible-paths (circuit distance).

Armed with these measures of environmental dissimilarity and geographic distance, Wang et al. used structural equation modeling to determine the contribution of IBE and IBD to genetic divergence (they redid the analysis a few other ways, to ensure their results were robust. Short answer: they were). They found that both IBE and IBD had a role, but that distance was of greater importance, with collinearity being much less of an issue than I, at least, initially guessed. Their results were relatively consistent across species and islands, though a few species, mostly Hispaniolan, were exceptions (you’ll have to read the paper to find out which ones). Regardless of whether you’re more interested in the general pattern across species (and islands), or in the exceptions, Wang et al.’s study will undoubtedly generate more research questions and spur future work.

Lastly, one of the paper’s aspects I liked best was how the authors used environmental niche models. Species distribution/environmental niche/ecological niche/spawns-of-hell models get a lot of flak from a lot of sources. Much of this is even deserved – however, this is often more the fault of the modeller than the model. As Wang et al. have shown, such models can still provide useful and interesting insights into ecological and evolutionary process. In fact, anole biologists are leaders in new and informative ways to exploit such models. Wang et al.’s paper certainly continues this (emerging) tradition.

Wang, IJ, Glor, RE & Losos, JB. 2012. Quantifying the roles of ecology and geography in spatial genetic divergence. Ecology Letters. doi: 10.1111/ele.12025

This Is Not A Madagascan Day Gecko

What baby wouldn’t love this?

We all know that geckos want to be anoles. But I fear I have unearthed a plot by an unidentified group of gecko-groupies to elevate the lowly gecko in the eyes of the public by forcing innocent anoles to masquerade themselves as (gasp) Madagascan day geckos. It all began several weeks ago, under the guise of a day trip to London to take in a little-known sporting event involving heroic UK demi-gods and demi-goddesses versus some other people (or so the BBC told me). Late in the day, we found ourselves wandering one of our favourite London haunts – the Natural History Museum. The mission: a gift for our soon-to-be-born niece (and where else would you go to find a gift for a newborn other than a natural history museum gift shop?). In the book section, I found a potentially better option: My First Book of Reptiles and Amphibians. It looked perfect – what baby wouldn’t love to be lulled to sleep by a full page close-up of a mouse disappearing down a viper’s throat or tidbits of information like “An adder’s bite is rarely fatal. It can cause mild swelling, and is very painful, but it is unlikely to kill you.” Imagine what herpetological feats said child would achieve later in life!
Continue reading This Is Not A Madagascan Day Gecko

Competition, Predation, and Selection: The Usefulness of Scientific Debate

Kidd Cay, one of the islands included in the Calsbeek and Cox (2010) study (photo from Losos and Pringle, 2011).

Chances are that if you read this blog, then you also tend to note when Nature publishes something anoley.  Thus, you’re probably already aware that last week Losos and Pringle published a reply to a paper by Calsbeek and Cox that appeared in Nature last year.  In that paper, C&C concluded that competition is a more important agent of selection than predation for island anoles.  In their reply, L&P point out limitations in the original study’s major assumptions, experimental design, and statistical analyses.  Rather than go into all the gory details, I suggest you look at their reply directly.  Just don’t let your non-anolologist colleagues or family members get a look at their Fig. 1a or you’ll lose any credibility you might have once garnered by speaking about the rigours of field work.  As is usual, C&C have also published a reply to the reply where they respond to the criticisms, re-performing some analyses.  Again, I don’t want to focus on the details; I’d rather let each reader decide for themselves.

Personally, I enjoy reading replies and replies to replies and if it gets to a reply to a reply to a reply, well even better!  It’s the way science should work – someone publishes something, there is debate, and the scientific community self-corrects if necessary.  However, recently an article in Ecosphere entitled “Do rebuttals affect future science?” by Banobi et al. challenged this view. Continue reading Competition, Predation, and Selection: The Usefulness of Scientific Debate