Archives: Evolution

Group selection, again. Yay.

I was amused to see that David Sloan Wilson took a weird poke at Dawkins, got thrashed by Jerry Coyne, and didn’t like it.  In fact, I was going to leave this as a link post, but while searching for a link to Coyne’s piece (Wilson can’t seem to figure out how to embed links to anything but his own blog in his posts) I came across a post by a blogger who calls him/herself “The Verbose Stoic”.  This piece is problematic on several points, but discussing this is going to take some space so I’ll do it here instead of a comment on Verbose Stoic’s blog;   from here on, I’m going to refer to him/her as VS.

VS starts off by questioning “examples”:

 What I want to talk about is the objections that Coyne raises against Wilson’s group selection theory:

Dawkins’s argument against the efficacy of group selection was that this form of selection is usually unsuccessful because groups are vulnerable to subversion from within by those selfish replicators. That is, “cheating” replicators that are “good” for individuals but bad for the group as a whole will tend to propagate themselves. Yes, altruism may help groups propagate, but altruistic groups are susceptible to invasion by cheaters unless the “altruism” is based on kin selection or individual selection via reciprocity.

That’s the main one, but he goes on to fill in more later:

Dawkins’s (and my) beef with group selection as a way to evolve traits that are bad for individuals but good for groups is that this form of selection is inefficient, subject to subversion within groups, and, especially, that there’s virtually no evidence that this form of selection has been important in nature.

Let me deal with the two minor ones before getting back to the main event. Starting with the last one, we can see that it’s a bad argument, because what Coyne is doing here is saying that one of the reasons to reject the examples Wilson’s giving of cases where group selection has been important in nature is … that you haven’t found examples of cases where it has been important in nature. Except, perhaps, for the specific cases Wilson is citing. You can’t in any way reasonably claim that the fact that you haven’t found examples of it yet means that you can dismiss this proposed example.

Look, Wilson isn’t citing any specific cases of group selection occurring in nature, mostly because there aren’t any.  When I say that, I mean that Wilson hasn’t been able to demonstrate that a trait arose because of group selection and not kin selection or natural selection or any other evolutionary force.  Wilson’s argument is that (1) group selection (a.k.a. “new” group selection or multi-level selection) is something different than any other variety of selection, and (2) that it is responsible for the evolution of traits such as altruism.  But (1) group selection reduces mathematically to inclusive fitness (follow the links in my previous post), and so (2) is trivially true.  Sure, it arose by “group selection”, but that’s an empty statement.  Wilson’s ‘proposed example’ is a theoretical model that was dealt with when he proposed it nearly 40 years ago (Wilson, 1975), and though it’s been refuted dozens of times since, he keeps holding on to it and insisting that he’s already won.   I’ll quote at length from West et al. (2007) to drive home the point:

It has since been shown that kin selection and new group selection are just different ways of conceptualizing the same evolutionary process. They are mathematically identical, and hence are both valid (Hamilton, 1975; Grafen, 1984; Wade, 1985; Frank, 1986a, 1998; Taylor, 1990; Queller, 1992; Bourke & Franks, 1995; Gardneret al., 2007). New group selection models show that cooperation is favoured when the response to between group selection outweighs the response to within-group selection, but it is straightforward to recover Hamilton’s rule from this. Both approaches tell us that increasing the group benefits and reducing the individual cost favours cooperation. Similarly, group selection tells us that cooperation is favoured if we increase the proportion of genetic variance that is between-group as opposed to within-group, but that is exactly equivalent to saying that the kin selection coefficient of relatedness is increased (Frank, 1995a). In all cases where both methods have been used to look at the same problem, they give identical results (Frank, 1986a; Bourke & Franks, 1995; Wenseleers et al., 2004; Gardner et al.,2007).

VS also isn’t happy about “efficiency”:

The first one is also a pretty bad argument when you look at evolution. The argument is that Wilson’s proposed solution would be inefficient, but it seems to me that one of the main thrusts of evolution is that it can indeed be — and often is — inefficient but as long as it works, that’s not a problem. When has it become a criteria for evolutionary explanations that it achieve maximal or even reasonable efficiency. To go down that route would risk re-introducing a need for a designer, to ensure that the mechanisms stayed efficient. That can’t be what Coyne wants. But, again, why is efficiency even a factor? Why would you sort evolutionary arguments by efficiency? Being more or less efficient isn’t a hallmark of evolutionary mechanisms, so if two mechanisms are proposed but one is more efficient than the other that says absolutely nothing about which one is more likely to be true.

Efficiency is a perfectly fine criterion to use, though the term is a little vague as used here.  Assuming that group selection is different from inclusive fitness (which it’s not):  if group selection results in an very slow rate of change in gene frequencies or a lower probability of fixation compared to inclusive fitness, then inclusive fitness is more ‘efficient’ and is more likely to be the cause of a trait fixating in a population.  At least, that’s how I would use the term;  I don’t want to put words in Dr. Coyne’s mouth, though I think that my view here is consistent with his usage and with the literature I’ve reviewed.  In other contexts, I’ve also seen ‘efficiency’ used to say that group selection wouldn’t actually the enhance relative fitness of altruism vs ‘cheating’ (which isn’t a great term for this, as I discuss below), which ends up in the same place.
In any case, VS seems to be confusing efficiency (whether Dawkins / Coyne would use it the way I do or not) with design.  Adaptations are often very badly designed, such as the case of the amazing recurrent laryngeal nerve, but that doesn’t say anything about how fast (or with what probability) genes for those adaptations spread through populations as a result of natural selection.  Even if group selection works the way that Wilson thinks it does, reasoning from the published theoretical models it’s easy to see why it would be an extremely inefficient process with its cycles of groups / reproduction as compared to overlapping generations with continual selection pressures.
VS finally goes onto what he thinks is the biggest error that Coyne makes:

That leaves us with the main complaint: cheaters. The main issue here is that there is an issue raised against the individual selection explanations of altruism as well, even kin and reciprocal altruism and it is … cheaters. Cheaters will benefit if they can get away with it, and so those individuals will prosper and those who are altruistic will be outstripped, and so altruism is not self-sustaining at the individual level. To get around this, the proponents of evolutionary explanations for altruism end up appealing to cheater detection mechanisms […]

Additionally, it seems to me that group selection can actually get this without having to apply specific cheater detection mechanisms. After all, group selection would imply that the relevant competing entity is the group. Thus, if a group has a significant percentage of people who are altruistic, then it outperforms groups that don’t. Thus, if you have a group where this happens and where too large a percentage of the group are cheaters, then that group will cease to get those benefits and be outcompeted and presumably eventually exterminated by the groups where that does not happen. Thus, group selection here becomes self-sustaining; if you are above or at the magical percentage that means you benefit from being altruistic, you benefit over other groups as long as it stays there, but if it ever drops below that your group may well collapse and your individuals, then, all lose. Note that we would still see cheater detection mechanisms emerge because they are mechanisms that make the group stable and so less likely to fall below that percentage and collapse.

It seems like VS might be on the verge of confusing old and new school group selection, as the bolded statements (my emphasis) suggest.  West et al.’s paper has a great figure that shows the difference between the two:

In the text of their article, they point out that “[a]nother way of looking at this is that the new group selection approach looks at the evolution of individual characters in a group structured population, whereas the old group selection approach looks at the evolution of group characters”.  VS’s own words make him sound like a disciple of Wynne-Edwards, which would be unfortunate since Wynne-Edwards was decisively crushed by George Williams in the 1960s.  But even if he’s just poorly recapitulating Wilson’s models, VS is still wrong on the evolution of altruism.  There are a number of possible explanations for altruism, including inclusive fitness, but I don’t want to get into a long conversation on how altruism might have evolved because I would have research and then write an inconveniently long book to do so.

Having said that, Coyne’s use of “cheating” (even in quotations) is a little unfortunate, because it overlaps with the literature on Prisoner’s Dilemma  and cooperation.  Cooperation and altruism are not the same concept (again, see West et al. for a good breakdown of the different concepts, or any text on social evolution);  altruism might be a subset of cooperation, depending on how you define the terms, but usually altruism comes at a cost to the altruist while cooperators do not necessarily pay a cost to cooperate.  “Cheating detectors” is more appropriate for a conversation about cooperation than altruism  (see also Figure 2 of this paper), which makes the rest of VS’s argument difficult to respond to.  I think that Coyne is using ‘cheating’ to refer to individuals who receive the benefit of altruistic acts without paying the price of altruism, but that’s not the same as cheating in models of cooperation.  (Honestly, ‘cheating’ isn’t a great word on a lot of grounds, including confusion with other areas such as signalling and an implication of conscious intent where none is necessary).

Returning to the posts that started this digression:  my honest belief is that this group selection debate should have been over years ago, but I will still support Wilson’s right to continue trying to make his case.  If he’s going to attack people like Dawkins and Coyne, though, he’d better learn to be prepared for them to hit back.  And though it’s unlikely that either of them will ever read this post, I’d like to tell them that they’re not alone.

P.S. Can I take this opportunity to point out a further example of Wilson claiming that people agree with him when they don’t?  If you read the end of Wilson’s second piece, he says:

For readers who are up for a challenge and want to learn more about the theoretical basis and empirical evidence for group selection from someone other than myself, I recommend Steven A. Frank’s “Natural Selection. III. Selection vs. Transmission and Levels of Selection (Journal of Evolutionary Biology, 2011). For Frank, it goes without saying that natural selection is a multilevel process and that the group level is often a significant evolutionary force.

I’ve actually read that paper.  In it, Frank once again points out that kin selection and group selection are the same thing:

The equivalence of r and Hamilton’s formal theory of kin selection establishes the exact equivalence of multilevel group selection and kin selection.

And then, after a long analysis, he compares the usage of the two methods in a section entitled (tellingly): Reasons to favour kin selection over group selection.  It contains exactly what the title says.  If you can get it and you like technical discussions of evolutionary biology, I urge you to read the paper yourself.  If you don’t, then just do me a favour and don’t accept Wilson’s claims about this paper at face value.

——–

David Sloan Wilson. A theory of group selection. Proceedings of the National Academy of Sciences, 72 (1):143–146, 1975.

S. A. West, A. S. Griffin, and A. Gardner. Social semantics: altruism, cooperation, mutalism, strong reciprocity and group selection. Journal of Evolutionary Biology, 20(2): 415–432, 2007.

Got questions about inclusive fitness?

Over at his blog, Andrew Gelman briefly mentions the recent profile of E. O. Wilson in the Atlantic, and along the way mentions the dustup over inclusive fitness that I may have mentioned here before  (did I? It’s hard to remember).   At the end, he makes a throw-away comment which drove me nuts:

The article also discusses Wilson’s recent crusade against selfish-gene-style simplifications of human and animal nature. I’m with Wilson 100% on this one. “Two brothers or eight cousins” is a cute line but it doesn’t seem to come close to describing how species or societies work, and it’s always seemed a bit silly to me when people try to loop everything back to a selfish-gene story.

I’ve been trying to think of a similarly aggravating comment to make about statistics in return;  maybe “lies, damned lies, and statistics”?  “You can prove anything with statistics”?  “Bayesian statistics suck because I don’t understand where priors come from?”  It bugged me enough that I left this comment:

It doesn’t seem like you know much about inclusive fitness, a theory has been massively successful in evolutionary biology. Despite the odd and unsupported comments made by Nowak et al., it stands firm as a well-supported and useful body of theory. Here’s a link to the letter published in response to Nowak et al.’s original article, signed by 137 authors including most of the field’s brightest minds:

http://www.nature.com/nature/journal/v471/n7339/full/nature09831.html?WT.ec_id=NATURE-20110324

The appeal to authority doesn’t mean that they’re right, of course, but extraordinary claims require extraordinary evidence; Nowak et al. have done nothing but ignore the entire published literature on inclusive fitness spanning decades and comprised of hundreds if not thousands of studies, while proposing a mathematical model that adds nothing to our understanding beyond what current theory already provides.

I respect your work on statistics, have always enjoyed reading your blog, and your book (BDA) is sitting on my shelf right now, but your offhand comment above is uninformed and very aggravating; I’d like to deal with that aggravation by offering to assist you in understanding one of the most powerful explanatory mechanisms in evolutionary biology. The letter above provides a succinct summary of the evidence that Nowak et al. ignore, but it might be a bit much for a non-technical audience; I haven’t published directly in this field, but I do work in evolutionary biology and I should be able to answer any specific questions you may have if you would like to pose them. If I can’t answer them myself, I will find people who can.

I’m not going to go into a full blown recapitulation of inclusive fitness theory and then defend it, because I’d have to write several inconveniently long books to do so.  But since I made the offer over there, I’ll make it here too for any interested readers:  if you have questions burning you up about this whole “inclusive fitness” thing, ask them here in the comments and I will do my best to answer them for you.  And if I don’t know what the answer is, I’ll find it.  No question is too small, though I make no promises on how long or short my answers will be!

I’ll leave off with a quotation from a fantastic book by Andrew Bourke that I’m reading right now, Principles of Social Evolution:

Like any large and active field of investigation, the theoretical study of social evolution is not free from disagreements and unresolved issues (e.g. Taylor and Nowak, 2007; West et al. 2007a).  Paradoxically, while the potential richness of inclusive fitness theory as a general theory of social evolution is still underappreciated, the theory is sometimes perceived as an entrenched orthodoxy. A tendency therefore exists for iconoclastically-minded theoreticians to derive models of cooperation in novel ways and then announce them to be fundamental additions to existing theory (e.g. Killingback et al. 2006; Nowak 2006; Ohtsuki et al. 2006; Traulsen and Nowak 2006).  It is healthy for orthodoxies to be continually challenged by new theories and new data.  However, to date, these models have fallen short of true novelty, as other authors have shown that their results are capable of being derived from inclusive fitness theory (e.g. Grafen 2007a, 2007b; Lehmann et al. 2007a, 2007b; West et al. 2007a).  Indeed, inclusive fitness theory has a long history of successfully assimilating apparent challenges and alternatives (Grafen 1974; Queller 1992; Lehmann and Keller 2006a).  This is not surprising when one considers its deep foundations in the theory of natural selection.  Although it is premature to declare a consensus, a substantial body of opinion therefore holds that claims of fundamental extensions to inclusive fitness theory will have to be radically innovative, as well as robust, to be accepted as such (e.g. Lehmann and Keller 2006a; West et al. 2007a).  For all these reasons, Hamilton’s (1964) inclusive fitness theory will underpin the conceptual reasoning employed throughout this book (pp. 22-23).

 

Group selection a done deal? Hint: no.

The modern theory of natural selection derives...

Image via Wikipedia

In reading Jerry Coyne’s review of David Sloan Wilson‘s new book, The Neighborhood Project, I came across this succinct summary of what I agree is the current feeling on group selection:

Group selection isn’t widely accepted by evolutionists for several reasons. First, it’s not an efficient way to select for traits, like altruistic behavior, that are supposed to be detrimental to the individual but good for the group. Groups divide to form other groups much less often than organisms reproduce to form other organisms, so group selection for altruism would be unlikely to override the tendency of each group to quickly lose its altruists through natural selection favoring cheaters. Further, we simply have little evidence that selection on groups has promoted the evolution of any trait. Finally, other, more plausible evolutionary forces, like direct selection on individuals for reciprocal support, could have made us prosocial.

These reasons explain why only a few biologists, like Wilson and E. O. Wilson (no relation), advocate group selection as the evolutionary source of cooperation. […]

At least, this agrees with my reading of the literature;  I’m hardly an expert in this area, but I’ve been swayed by the writings of people like Coyne and the pair of Stuart West and Andy Gardner (e.g. this paper, if you can get it;  this video is also well worth watching).  And nothing D.S. Wilson has ever written has convinced me otherwise.  Thus, I was especially surprised when I picked up a free copy of New Scientist from the Ultimo Big Night of Science – which, incidentally, was fantastic –  and saw that they had published an 8-page hatchet job (which is behind a paywall online here) by Wilson in which he claimed that group selection (a.k.a. multi-level selection or MLS) “is firmly re-established” in evolutionary biology.    “Today, though,” he writes, “there is near-universal agreement among those familiar with the subject that the wholesale rejection of group selection was mistaken and that the so-called alternatives are nothing of the sort” (p. viii).

One of the biggest problems with group selection is that it’s mathematically equivalent to other, better explanations of evolution like kin selection.  Wilson knows this:  he rather transparently tries to co-opt the criticism in the paper by stating it as though it works in reverse (“In addition, it has become clear that the supposed alternatives for the evolution of prosocial behaviour are actually equivalent to group selection”).  In what I consider a despicable move, he even quote mines Andy Gardner:  “‘Everyone agrees that group selection occurs,’ stated evolutionary biologist Andy Gardner in 2008.”  But it’s instructive to look at what Andy Gardner actually said, in this 2008 Nature summary of the ‘debate’:

 “Everyone agrees that group selection occurs,” says Andy Gardner of the University of Edinburgh, UK. Yet Gardner and his colleagues Stuart West and Ashleigh Griffin have trenchantly criticized David Sloan Wilson’s arguments on this subject — a critique to which David Sloan Wilson responded by initiating a lengthy debate in the community under the heading ‘If the theorists cannot agree…’.

Wilson leaves off the part where Gardner and his colleagues don’t agree with him at all, which is a favourite tactics of creationists.  I’ll leave the implication of that up to the readers.

So if everyone agrees that the two are mathematically the same, why not use group selection?  I’ll highlight the strong argument made by West, Griffin, and Gardner which you can read here.  In responding to Wilson’s critique of an article that the authors wrote, West et al. point out three things (p.376):

  1. “No group selection model has ever been constructed where the same result cannot be found with kin selection theory.”
  2. “The group selection approach has proved to be less useful than the kin selection approach.”
  3. “The application of group selection theory has led to much confusion and time wasting.”

If you’re interested in this issue, I urge you to read the linked PDF and follow up with some of the references they give.  I don’t know of clearer writers on this subject, and it’s a great place to start.

I disagree with a lot of what D. S. Wilson writes, but I respect his right to hold the opinions and his efforts to prove his position right.  That’s how science progresses, and if he can ever come up with some strong evidence for his position (which I don’t believe that he has yet), I’ll take a good hard look at it and make up my mind anew.  Until then, though, I would take him much more seriously if he would stop with the claims that everyone agrees with him when they obviously don’t.

Outside your area…

This post at Ars Technica by Chris Lee says smart things about a subject that I’ve been thinking about for a while:

One of the most important things that I’ve learned in my time writing for Ars Technica is how little I know. Look at my back catalogue of stories and you will notice that most of my articles are combinations of quantum mechanics and optics. Every now and again I venture into the fraught territory of cosmology, materials sciences, and climatology. Even more rarely, I head off into the wild and write something about medicine or biology.

I only ever write these articles if the papers on which they are based are written clearly; I want to be reasonably certain that I haven’t mangled the research entirely. Yet, if you let yourself be flushed down the intertubes, you will find physicists and engineers like myself expounding on topics that are far outside their field of expertise. These people are often so badly wrong that it is hard to know where to begin in any argument to counter them.

I find it quite frustrating because these are supposedly smart people. So what goes wrong with us physicists?

(The rest of the post is great , so go read it!)

I truly don’t think that the phenomenon is restricted to physicists, mind.  I’ve met more than a few people from all different kinds of fields who feel that their Ph.D. or other advanced credentials makes them qualified to pontificate on any subject that happens to be at hand, and worse, makes them expect that they’re right without any evidence.  A favourite example from my own life might be the social psychology grad student who wandered up to me during an exam we were proctoring together and told me that this evolution stuff was bunk when it came to humans and that evolution had never had an effect on humans – we’re special, damnit.  And he wasn’t having any suggestions to the contrary – he nearly had his Ph.D. after all, and I was just a jumped-up Master’s student. And it’s worse these days.  If I have to deal with one more engineer who wanders over and tells me about how evolution is full of holes and s/he knows just what they are (after which they usually proclaim that evolution violates the laws of thermodynamics or something equally inane and well-refuted), I’m going to scream.

Of course, I’m convinced that the same is true for people coming from my patch of the woods;  I’m willing to bet money that there are plenty of biologists who wander all about the place spewing nonsense because they know about teh evolutionz.  (I wonder if doctors find biologists insufferable as patients?)  If anyone has examples, I’d love to hear about them!

The Nowak controversy resurfaces…

Over at Boing Boing, Maggie Koerth-Baker takes up the issue of eusociality in insects that Martin Nowak and E.O. Wilson (and Tarnita, though she doesn’t get much attention when this issue is raised – I wonder if that makes her happy or sad?) raised such a hullabaloo over last year.  If you’re new to the issue or just enjoy good science writing, it’s well worth reading all the way through.  My own perspective?  I’m with most of the field in thinking that Nowak et al. were out to lunch on the evidence for kin selection, and as to whether group selection is in operation … well, let’s just say that I found this talk very convincing (h/t for that to Jerry Coyne).

Evaluating the fitness consequences of signalling…

Robert Kurzban, over at the Evolutionary Psychology blog, has a post up which caught my attention because it deals with an area of behavioral ecology that I happen to know a little bit about:  signalling.  My master’s degree was done on animal aggressive communication models, under the supervision of Pete Hurd.  So I was intrigued to see what Robert had to say.

The post itself was fairly underwhelming for me, because Robert only seems interested in using a (somewhat overstated) terminological dustup over signals versus cues.  But about halfway through the post, he decides to throw a rather large stone in a surprisingly glass house:

Let’s turn to the substance of the matter. Maynard-Smith and Harper (2003) define a signal as “any act or structure that alters the behaviour of other organisms, which evolved owing to that effect, and which is effective because the receiver’s response has also evolved” (p. 3).

Their first example is distinguishing two ways a stag might make another stag retreat: push him or roar at him. Pushing, they argue, isn’t a signal – it does alter the behavior or the other organism, but the response, moving backwards, didn’t evolve as a response to pushing – it’s simply a physical consequence. In contrast, retreating in response to a roar, they argue, makes the roar a signal. Roaring evolved because retreating from roars is an evolved response, the argument goes.

Note how casually Maynard-Smith and Harper make this strong claim. Labeling the stag’s roar a signal is an adaptationist claim, that the behavior in question has a function, in this case, conveying information – signaling – to a rival which, in turn, is useful in the context of intra-sexual conflict. I find it worthwhile to reiterate, at the risk of undue repetition, that this illustrates how biologists routinely make adaptationist claims based on observed patterns of behavior, rather than measuring fitness consequences, heritability, and the like.  [Emphasis mine].

I was astounded by this claim for two reasons.  First, an evolutionary psychologist is telling biologists that they don’t measure fitness consequences?  When was the last time an evolutionary psychologist did an experiment in which they manipulated a trait and measured fitness consequences, i.e. survival and / or babies made as a result?  I would love to be on the ethics committee that processes that application, I really would.  Every EP study that I have ever read which deals with fitness in any way is either a correlational study (e.g. using historical birth record data or doing a cross-sectional analysis) or uses some proxy  for fitness, like asking women to rate the attractiveness of male body odours that they sniffed from used t-shirts to assess the “fitness consequences” of MHC (major histocampatibility complex) preferences.  Don’t get me wrong, I find a lot of this work interesting, but to criticize biologists for not assessing fitness consequences is quite the santicmonious move.

In behavioural ecology we often do as the MHC researchers do and use proxies for fitness, by which I mean that we measure a trait that we argue (or assume) is correlated with fitness.  For instance, in foraging research, we assume that food intake rates will correlate with fitness and so suggest that the adaptive value of a behavioural trait can be measured – at least indirectly – by manipulating the trait in some way and seeing how that impacts food intake.  Would we prefer to measure fitness directly?  Sure we would!  The reasons we use proxies usually boil down to the difficulty, or downright impossibility, of measuring fitness in that way.  Primatologists, for instance, are going to be about as likely to perform such direct fitness studies as evolutionary psychologists are, and even those of us who work with smaller and easier to handle animals are going to find such research challenging.

But that brings me to my second objection, which is that biologists do measure fitness consequences (and heritability, and the like, but I’ll focus on fitness here).  Some examples:

–  The obvious:  twisting Drosophila into various shapes and seeing the consequences (fitness or otherwise) of that is practically an industry by now.  It took me about four seconds and a single Google search to find a nice-looking study on sexual selection and fitness outcomes in Drosophila by Promislow et al. (1998), and the related links lead to a flood of more recent research.
–  The awesome:  many examples are found in sexual selection research, for obvious reasons.  Frogs have some good examples of this, like work on the Australian frog by Jeremy Robertson that showed that female choice of male calls was adaptive by showing the consequences to female clutch fertilization by a mismatch between call and male body size.  And I’m pretty sure that Mike Ryan, who has done a lot of incredible studies on the signalling system in túngara frogs, would be surprised to find out that biologists don’t assess fitness consequences.

–  The vaguely frightening:  ever seen hermit crabs fight?  It’s a bit scary.  Check out this video from the Royal Society in which one crab thoroughly kicks the snot out of another and then steals the other guy’s house:

Research on the fitness consequences of these fights goes back decades, both intra- and interspecifically.  The signalling system used by hermit crabs (like shell rapping) is also a fascinating area of study.

–  The avian:  birds are a common target for this, too.  A particular example I like comes from an area close to home, the zebra finch.  Remember the assumption I was talking about above, using foraging intake rates as a proxy for fitness? William Lemon decided to test this directly, and so he manipulated the feeding rates of four zebra finch populations to determine the adaptive value of energy maximization (and its suitability as a proxy for fitness) by directly measuring survival and reproduction in the populations.  Show me the EP study that does that.

This is just a short list cobbled together from what I can think of off the top of my head and some quick Googling, and I even confined myself to just studies looking at reproductive benefits;  many more have done work on the survival component of fitness, and to cover even a fraction of those would require an inconveniently long book.  Even the examples I’ve chosen are slanted towards behaviour, for obvious reasons, and people skewing towards the genetics side of things have done a lot more work on these types of questions than we have in behavioural ecology.

When I began my undergraduate career in psychology, I was attracted to evolutionary psychology.  I felt then, as I do now, that the core concept of taking evolution’s effects on homo sapiens into account is true and needs attention.  It’s what inspired me to shift to biology, so that I could study the tools of biology and bring them back to the sort of questions that EP studies.  And if Robert’s feelings are shared by other current practitioners of EP, I can’t help thinking that the field needs more people who will do the same.

Interesting new site -> “Phylointelligence: Evolution for everyone”

At this point, my site stats tell me that this blog has somewhere around 1 reader, and that might actually just be me (wait, am I violating some sort of blogospheric fourth wall here?). So, I feel a little ridiculous posting links that no-one will read,  but this site is such an interesting idea that I’m willing to shout into the void:

Phylointelligence: Evolution for everyone.

The site is well-designed and though the content is still a little rough, I like the idea of cataloging the evidence for evolution in a way that is accessible to general readers.  I also like the focus on the overlapping lines of evidence which support evolution.  It’s a site that I’ll be keeping an eye on, and if I can find the time, maybe I’ll even contribute something to it…

[h/t: Pharyngula].