Category Archives: Biology

Now that we’ve found Nemo, it’s time to save his friends.

Nemo! Picture by Peter E. Lee, used under a CC license.

There’s many things that we don’t know about the ocean, and most people won’t find that too surprising, but what might be surprising is the extent of our ignorance in some areas.  This is the subject of a recent paper by McClenachan et al. in the journal Conservation Letters, entitled “Extinction risk and bottlenecks in the conservation of charismatic marine species.”  The problem, they contend, is that while the oceans are currently undergoing a massive loss of biodiversity, the full picture of that loss cannot be seen because we’re not even close to knowing how many species have been lost or how many are currently threatened with extinction.

As a small first step to dealing with that issue, the authors of this paper examine marine charismatic species as a way of estimating the threat to some of those species and identifying possible impediments to their conservation.  What are charismatic species, you ask?  They’re species with widespread appeal that receive more attention and funding for conservation (some might say too much attention and funding);  it’s suggested that charismatic species can raise awareness and drive conservation goals.  In this paper, the authors leverage the fame and fortune of marine charismatic species by arguing that because they receive special attention and are – theoretically – at the least risk of extinction even when threatened, charismatic species can serve as an estimate of the lower boundary of the probability of extinction.

The paper takes an unusual and amusing tack to do so.  In their own words: “we summarize the extinction risk of 1,568 species within 16 families of well-known marine animals represented in the 2003 Academy Award-winning movie, Finding Nemo“.  It’s not many papers in which you get to start “with all major characters, as defined by those with credited speaking parts”, including all species in their taxonomic families which included invertebrates, bony fishes, elasmobranchs (sharks and rays), birds, and turtles.  You can follow through the paper for the exact details of how they constructed the lists, but they then took that list of species and evaluated their risk of extinction.  Following that, they evaluated the potential bottlenecks to conservation among the various families. There’s a lot of fascinating detail in this paper, but I’ll skip to the punchline and let you read the rest for yourself.  For me, the most interesting aspect of this paper is captured by Figure 3:

Here we see that many species, especially in the invertebrates and fishes, are almost entirely ignored either in terms of scientific effort (here the number of papers published on the species), status evaluation (are they endangered?), or conservation assignment (listed by CITES, the species-protection for threatened species).  The authors point out that the charismatic species like turtles and birds receive the bulk of the attention at every level, while conservation bottlenecks arise in the other families.

The focus on Finding Nemo is an amusing hook, but though the paper deliberately trades-off rigor for rhetorical power, the argument that the authors make is a clear and important one.  In calling for a greater focus on the marine biodiversity being lost before our eyes, McClenachan and her coauthors make a great point and deserve the attention that they received for publishing this paper*.

Having said all that, there’s a lot left that to talk about regarding the issues that this paper raises.  In particular, I’m struck by the elements of economics, social psychology, and sociology that would interact with the conclusions of the authors’ work.  The fact is that conservation is, and probably always will be, a finite resource (limited in part by money, and in part by scientific personnel) that must be spread about the overwhelming number of species that are likely to be threatened.  This isn’t to say that the status quo is right, or that we shouldn’t strive to improve it – quite the contrary.  But even in the best of all possible worlds, the fallible human beings tasked with the goal of saving these species (scientists, polticians, the general public) are going to exhibit biases of cognition and simple attention that may make it difficult to drum up support for, say, many of the invertebrates in the paper’s list of species.

Take another look at Figure 3 and try to imagine reasons why some of these species might be relatively ignored.  Off the top of my head, a few potential hypotheses jump to mind.  Physical features of the species’ in question may play a role;  for instance, simple preference for anthropomorphism could account for some of the attention paid to the charismatic megafauna.  It’s easier to care if you can imagine the animal talking but it’s a lot easier to imagine a talking shark or clownfish than a talking shrimp (and don’t discount preference for neoteny;  this paper by Mark Estren looks like a good read on that subject).  Or, even something as obvious as size could play a role:  it’s a lot harder to find or pay attention to many of these marine invertebrates than the turtles or sharks or birds that they compete with.

Even the sheer number of species involved could be important, in more than one way.  On one hand, the fact that there are 6 species of turtles compared with 536 species of invertebrates in this paper seems relevant, as the sheer effort involved in finding and cataloguing the marine invertebrates is daunting.  On the other hand, I’m also reminded of work in economics by people like Barry Schwartz and Sheena Iyengar on the paradox of choice:  when confronted with too many options, people are unhappy and find making decisions difficult, even though they claim that they prefer to have more choices available to them.  The number of possible targets in marine invertebrates for conservation efforts could drain the will of politicians, the attention of the public, and the interest of new grad students selecting a species to work on.

I wouldn’t be surprised at all to hear that the people involved in conservation work have thought about some or even all of these issues, but I would not hesitate to recommend a multidisciplinary approach to this problem.  The answer to the call put out by McClenachan and her co-authors has to include a sober analysis that maximizes the efficiency of the resources we have while, perhaps, searching for innovative new ways to increase those resources.  Here’s one thought:  maybe it’s time for a Kickstarter for conservation – a ConservationStarter?  If the idea of a charismatic species is to reach its fullest expression, I can imagine that it might be in the form of directly crowdfunded conservation efforts targeted at particular species.

Whatever we do, the authors of the paper make it clear that we have to do something, and that our actions have to start with knowledge.  There’s simply too much out there that we don’t know;  we may have found Nemo, but we don’t know very much about his friends and we’re in danger of losing them too.

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Loren McClenachan, Andrew Cooper,, Kent Carpenter, and Nick Dulvy (2012). Extinction Risk and Bottlenecks in the Conservation of Charismatic Marine Species. Conservation Letters, 5:73-80.

* My post isn’t especially timely when it comes to this paper, as it was published in January, and others have written about it before me;  a good example is the fine folks over at Southern Fried Science or the Scientific American blogs.  However, the paper was only recently brought to my attention by the good folks in Bill Sherwin’s lab, and the discussion we had about it inspired this blog post.

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Do you know this bird?

Google has failed me (even the reverse image search, which failed rather spectacularly), and since it worked so well last time, I thought I’d ask the readers once again:  any idea what species this bird hails from?

It was spotted while at the walk-in aviary near Canberra, surrounded by dozens of species of parrots, cockatoos, finches, and more.  But there was no picture on the board identifying it, and I forgot to ask on the way out.  So, if you know this bird let me hear about it in the comments!  A prize will be given for the first correct answer*.

* The prize is a lie.  There is no prize.

Update:  pete chimes in below with what I think is the correct answer:  the Rose-ringed Parakeet (Psittacula krameri) found in Africa and Asia according to Wikipedia.  The internet FTW!

The Rose-ringed parakeet, with a colour mutation to blue...

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A quick follow-up to DolphinGate: cool science!

One of the things that surprised me about the weekend’s DolphinGate flap was that most of the mainstream articles I read were acting as though the paper that they were wildly misinterpreting was providing the first evidence for dolphins engaging in same-sex behaviours.  The Huffington Post is a great example of this;  here, for example, is the first paragraph of their story:

Dolphins were once humorously alluded to as “gay sharks” on an episode of “Glee,” but a new study suggests that bisexuality and even homosexuality among the marine mammals may be very much a reality.

I’ll admit that this caught me off guard, because I was under the impression that the dolphin same-sex play was a well-established fact.  How was everyone reporting this as a big surprise?  Yet when I spent a few minutes poking around on Google Scholar, I couldn’t immediately find a good reference for when this was first talked about in the literature.

Thankfully, the internet provides all!  Justin Gregg of the Dolphin Communication Project mentioned my piece on Twitter and, seeing an opportunity to get to the bottom (?) of this, I reached out to ask him if he knew when these behaviours were first observed.  Justin came through in a big way:

1948!  I can’t get at the actual paper (#icanhazpdf?), but the abstract is a gem of scientific understatement:

A summary of observations of captive porpoises is given. Vision and hearing are well-developed, and vocalizations are produced in the form of “jaw-snapping,” whistling, and barking. In captivity the porpoise shows a diurnal sleep cycle. There is a stable dominance hierarchy. Both homosexual and heterosexual behavior has been observed, as well as masturbation in the male. An instance of live birth is described. The play of the porpoise is complex and goes on for long periods. They manifest many and definite fears. The homologies of these types of behavior with that of other mammals is discussed. When various characteristics of porpoise behavior are considered and compared, the animal may be located at many different points in a scale of phylogenetic complexity. Although no information is available on problem-solving in this form, other types of behavior place the porpoise at a place in the developmental scale between the dog and the chimpanzee.

I’ll have to own up to my own foibles here, though, because the conversation may have gone a little down hill after that.

[Insert your own jokes here….]

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Science journalism blows it, dolphin rape edition.

A few weeks ago I got into a discussion on Twitter with Ananyo Bhattacharya, online editor of Nature News and writer for The Guardian’s science section, after he put out a call asking for ways to improve science journalism. During that conversation, I argued that one way to do this is to create a culture of journalism that values scientific knowledge and expertise as a core value[1]. Ananyo seemed unimpressed with my viewpoint, and suggested that the main point of science journalism was to pry into the dark corners and root out biases, fraud, and the like in science. He views scientific communication and scientific journalism as two distinct things (and thinks that journalists doing ‘PR for science’ is ‘drippy’). Indeed, when asked directly during a Royal Institute forum on science journalism whether journalists should read the original papers behind the stories that they write, he dismissed the idea:

“If the question is ‘must a good science journalist read the paper in order to be able to write a great article about the work’ then the answer is as I said on Tuesday ‘No’. There are too many good science journalists who started off in the humanities (Mark Henderson) – and some who don’t have any degrees at all (Tim Radford). So reading an academic research paper cannot be a prerequisite to writing a good, accurate story … So I stick to the answer I gave to that question on the night – no, it’s not necessary to read the paper to write a great story on it (and I’ll also keep the caveat I added – it’s desirable to have read it if possible).”

He further suggests, in the same comment (original source), that if journalists had to read original papers than no one could report on particle physics[2].

I’m not going to try and hide my bias here: I don’t like Ananyo’s viewpoint on this. I don’t think that it will lead to good writing, either of the communication or journalistic variety, but more importantly I think that forcing journalists to read the papers before they write an article might have stopped stupid @#$@ like what happened today from happening at all.

The story: I received an e-mail this morning from Dr. Bill Sherwin, a member of the Evolution and Ecology Research Centre (E&ERC) here at my current institution, the University of New South Wales. Bill is one of the authors on a new paper coming out in the Proceedings of The Royal Society (B), entitled ‘A novel mammalian social structure in Indo-Pacific bottlenose dolphins (Tursiops sp.): complex male-male alliances in an open social network’. The paper is a nice little exploration of the characteristics of social networks in dolphins found in Western Australia; in essence, they were testing whether two hypotheses about the nature of these social networks were tenable given the data they’ve observed. In particular, they tested whether dolphins show signs of engaging in ‘community defence’, where higher order alliances of dolphins form to patrol and defend a larger community range, similar to chimpanzees, or if it follows a ‘mating season defence’ model where male groups shift their defence to smaller ranges or sets of females when it’s mating season. The comparison to terrestrial species with complex social cognition (such as primates and elephants) is an interesting one, because it provides yet more insight into the relationship between the development of complex cognitive faculties and social relationships.

So far, so good. Bill gave a simple explanation of the paper in an email that he was sent out to the E&ERC this afternoon:

We put out a paper that said “dolphin male alliances are not as simple as other species”, but it has stirred up quite a lot of interest, because somewhere in it, the paper mentioned “bisexual philopatry”, which when translated out of jargon means  “males stay near where they were born, AND females stay near where they were born” – nothing more or less than that.

‘Quite a lot of interest’ is one way to put it. ‘Idiots crawling out of the woodwork’ is another. Here’s the headlines of four stories that were written about this paper:

Dolphins ‘resort to rape’: Dolphins appear to have a darker side, according to scientists who suggest they can resort to ‘rape’ to assert authority. [The Telegraph]

Male dolphins are bisexual, US scientists claim. [news.com.au]. (Note that this is an Australian website, and Bill is Australian).

Male bottlenose dolphins engage in extensive bisexuality. [zeenews.com]

And by far the best of the lot (guess who it’s from?):

The dark side of Flipper: He’s sexual predator of the seas who resorts to rape to get his way. [That’s right, The Daily Mail].

……..

Are you kidding me? If the ‘writers’ of these articles had read the paper, they would have noticed that it contains nothing about the sexual behaviour of the dolphins they studied, bisexual or otherwise, aside from brief mentions of the possible consequences of social networks on reproductive success. It certainly didn’t mention anything about bisexual behaviour, homosexual behaviour, or rape. Now, it’s well known that dolphins engage in homosexual behaviours, and I’ve seen papers arguing that they use sexual coercion as well (Rob Brooks confirms this). But these topics have nothing to do with this paper at all. Even a cursory glance through the original source would have killed these headlines – and the first few paragraphs of the Mail story – which aren’t just a miscommunication but border on outright fabrication. The articles themselves are weird mixes of sensationalist headline with a regurgitated paraphrasing of the much better Discovery News piece that they are treating as the primary source. Here’s the problem, though: it’s Discovery News that makes the original mistake about ‘bisexual philopatry’, interpreting it as bisexual behaviour (hot male dolphin-on-dolphin action, as it were). A reporter who had read the original source could have corrected that mistake fairly easily, or could even have been driven to ask further questions. Without that, however, the press cycle grinds mercilessly forward to Flipper the bisexual rapist.

For my part, I was happy to see that James Randerson’s informal survey of science and health writers showed that many of them do read the original papers. And the kind of people who write things about science that I trust, whether they’re professionally trained in science or not, are not the sort of people who do boneheaded things like this. Ananyo might retort that ‘asking questions’ is enough (he suggested as much in his comment above). Matt Shipman said much the same thing in the piece that Ananyo was commenting on. Yet of all people, Ananyo should be wary of this answer, with his focus on investigative science journalism. A scientist writing an email or doing a phone interview can tell you just about anything that you want to hear; a press officer can write a terrible press release; a wire service will probably distort what comes down the line. But a scientific paper is the One, True Source. It is a public record of what was done, and it is the first and best place to start for answers about a study or a scientific topic[3].

Don’t mistake my criticism of Ananyo’s position of reading scientific papers as a general attack on scientific journalism. I think that there’s a lot of great science journalism out there, and that there are even more great science journalists and communicators. Despite the perennial swirl of internet discussion on the topic, I don’t actually think that the whole field is hopelessly broken like some seem to. I just happen to believe that scientific papers, the products of our time and energy as researchers, form an integral part of the process of talking about science (and it’s part of the reason for my support for Open Access publishing). And I think that disgraceful trainwrecks like the reporting on Bill’s paper are a perfect illustration of the need for these papers to be a part of that process.

[Update: Rob Brooks has also discussed this issue over at TheConversation].

——-

[1] Because of Twitter’s space constraints, this was misconstrued to mean that I was agitating for all science journalists to have a Ph.D. in a scientific discipline. Though I wouldn’t be upset if this happened, that’s not what I meant: it is more than possible to have a deep love and knowledge of science without having a degree in a scientific field. Hell, Carl Zimmer probably knows more about viruses and evolutionary biology than I do, and his only training is an undergraduate degree in English. My argument is only that having scientific training increases the probability of a writer or journalist having a good grasp on how science works, not that it’s the only way for that to happen. I will continue to argue, though, that those having a love of science (professional or amateur) will, on average, produce better science writing and science journalism than those who don’t.

[2] He also claimed that most of the people asking journalists to read papers are biologists and medical people, who write easier-to-understand papers. I would have to turn this back on him: if biology and medical papers are so easy to understand, why shouldn’t journalists read them every time?

[3] Yes, there’s no guarantee that what is written in the paper is true. But the chances of detecting fraud are essentially zero if you don’t read the paper to begin with, and if you’re a journalist looking to catch the next Stapel, chances are that you’ll have to wait for the scientific community to find him and tell you about it anyways.

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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.

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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.

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It’s true!

As seen on Twitter:

The "what X does" meme for evolutionary biologists...

I really have nothing to add to this...

Also, don’t miss the closely related Scientists version…

Can we just agree on a name?

An image of a squirrel with personality

A squirrel with personality, from jpaxonreyes (used under a CC license). Because let's face it, this post needs a picture.

Looking at the email alerts I get for new journal issues, I came across a new paper by Sih et al. in Ecology Letters [1], looking at the “ecological implications of behavioural syndromes”.  And I suppose that I could talk about the content of the paper, but what I’d rather do instead is go off on a short rant about research on this topic, as is my right as a blog writer.  What’s got a bee in my bonnet (and why am I suddenly 90 years old)?  It’s the name, “behavioural syndromes”.  It drives me mad.  I’ve seen papers refer to the topic by:

  • “Animal personality”
  • “Behavioural syndromes”
  • “Coping styles”
  • “Animal temperament”
  • “Interindividual variation” – not an SEO friendly description, to be sure.

There seems to be a political aspect to this too, but I’m not 100% clear on it.  Some themes are clear, though.  My feeling is that Sih seems to be pretty stuck on “behavioural syndromes”, while others like Denis Réale (whom I know from my Ph.D. at UQÀM) and Neils Dingemanse seem to be throwing spaghetti at the wall; after trying to introduce “animal temperament” as a thing – which, as far as I can see didn’t take hold – they had the (actually quite inspired) idea of doing an end-run around the whole thing by combining personality with plasticity and coining the new phrase “behavioural reaction norms” [3].  Only time will tell if that one takes off.

Lest you think that it’s just a name problem, it seems that confusion in the names is a symptom of deeper confusion over what they’re studying and how to study it.  Hanging around at a couple of the discussions at the last ISBE made it clear that people working in this field aren’t agreeing on the name, the definition, or the methodology (statistical or experimental).  Some of this is cause for excitement, of course:  when you’re this confused, it’s probably a sign that you’re on to something good.  And don’t think that I’m writing the area off;  there’s been a lot of exciting work in personalities over the last decade or so.  Hell, I’m trying to get a paper published on the topic myself right now.  Yet, I can’t help feeling that work in this area is going to be a little bit hamstrung until it converges on clear values for each of these things.

And honestly, I just feel sorry for the next poor sod who wants to do a literature review or meta-analysis.  So, can we just agree on a name and call it a day?

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[1]. Andrew Sih, Julien Cote, Mara Evans, Sean Fogarty, and Jonathan Pruitt. Ecological implications of behavioural syndromes. Ecology Letters, 15(3):278–289, 2012.

[2]. Denis Réale, Simon M. Reader, Daniel Sol, Peter T. McDougall, and Niels J. Dingemanse. Integrating animal temperament within ecology and evolution. Biological Reviews, 82(2):291–318, 2007.

[3]. Niels J. Dingemanse, Anahita J. N. Kazem, Denis Réale, and Jonathan Wright. Behavioural reaction norms: animal personality meets individual plasticity. TRENDS in Ecology and Evolution, 25(2): 81–89, 2009. 

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Is it the 1960s again?

Ritual Sacrifice of the Gummulate Tribe!

Ritual Sacrifice of the Gummulate Tribe! by Grizdave, used under a CC license

 

Found in a textbook today ([1], p. 14-15), immediately following a discussion of Ebola and Lassa fever infections in humans:

While having the death of a host individual occur as the product of an encounter with a pathogen may seem like a dire outcome, this outcome represents a mechanism of defence operating at the leve l of the host population.  If a particular infectious agent is something against which members of the host population could not easily defend themselves, then it may be better to have that particular host individual die (and die very quickly!) to reduce the possible spread of the contagion to other members of the population.

In other words, if it looks like you’ve been infected by something nasty, you sacrifice yourself to stop its spread for the good of the other members of your population.

Look, I’ll be the first to admit that I hold a dim view of multi-level selection, but I’d be really surprised if anyone in the MLS camp were to make an argument as simple-minded as this.  Virulence is a complex topic, certainly, but the above paragraph could have been lifted from a previously-unknown book by Wynne-Edwards in the 1960s and no one would know the difference.  How is it that people are still getting away with stuff like this forty years after it was first shredded by the likes of George Williams and John Maynard Smith?

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1. Christon J. Hurst. Defining the ecology of viruses. In Christon J. Hurst, editor, Studies in viral ecology, volume 1, chapter 1, pages 3–40. John Wiley and Sons, Inc., 2011.

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Unidentified: any spider people recognise it?

Spider people, leave me a comment if you know anything about this spectacular individual, found in Sydney while I was walking to lunch:

Unidentified spider I saw on my way to lunch...

Captured with my iPhone 4S...

 

Update: Twitter responds!

 

 

 

 

And a quick email to one of UNSW’s spider gurus, Michael Kasumovic, confirms that this is probably a juvenile of Nephilia plumpies.  Thanks, guys!

 

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Parents and personality in the animal world.

Animal personality is a huge topic in behavioural ecology right now, and it seems like you can’t shake a stick in the literature without hitting another paper on the subject.  You may have heard of the term before, but if you’re asking “what is animal personality?”, I’m planning to write on the topic more extensively soon and so I ask that you bear with me and keep an eye out for that.  For now, we can go with a sensible version that defines animal personality as “consistent individual differences in behaviour, in time and/or across contexts, for both human and non-human animals” (Dall, Houston, & McNamara 2004).  In non-scientist speak, this means (broadly) that animals show personality traits in the same way we think of when we talk about humans;  when we say “he’s an aggressive person”, we mean that no matter what context you find him in, the person we are talking about expresses aggression. In a boxing ring, aggression is appropriate, but while it may not be so appropriate in the middle of a grocery store he expresses it anyways.   The study of personality traits in animals, where animals who are aggressive or exploratory or shy in one context tend to be so in others, has exploded in recent years and the signal can sometimes get lost in the noise.  To that end, I want to highlight a new paper in the Advance Access section of the journal Behavioral Ecology by Adam Reddon, entitled “Parental effects on animal personality”.

Rat image by ressaure; used under a CC license.

(Full disclosure:  Adam is a friend from my Master’s lab, and he’s scary smart.  He’s currently doing his Ph.D. at McMaster with Sigal Balshine and publishing papers at a rate that most people can only envy.  If you’re looking for young behavioural ecologists – or scientists in general – to watch, he should most certainly be on your list).

The point of this paper, an invited forum contribution, is to link the large literature on parental effects and animal personality.  Parental effects (though most work has been on maternal effects) cover “the ways parents can shape their offspring’s phenotypes over and above genetic inheritance”, as Adam puts it.  These effects can occur in many different ways, which Adam does a nice job of reviewing;  examples include nest site selection, the amount of food provided,  hormone transfer by birds into their eggs (which can, among other things, manipulate how fast the offspring grows), social interactions, and providing opportunities for social learning.  One great example that he provides is of Norway rats.  Rat mothers will lick and groom their pups after they are born, and the amount of licking and grooming that the pups experience in the first week will have big effects on how well the pups respond to stress both physiologically and behaviourally.  Pups who were interacted with less tend to be “shyer, less exploratory, less social, less aggressive, and less dominant” throughout their lifespan (p.2). This is clearly a parental effect, because pups who were cross-fostered (adopted) to other mothers had stress reactions that came from the licking and grooming of their adoptive mother and did not correlate with their genetic mother. Paternal effects are also quite widespread, having been seen across taxa, including mammals, birds, lizards, and even waterfleas (Daphnia cucullata) and radishes.

Adam’s contribution here is to draw a straight line between the two literatures by connecting developmental processes to animal personality, treating personality as an outcome instead of the starting point.  As he states (p. 2-3):  “… the parents of a developing organism are in a unique position to guide its development and alter the offspring’s personality to better match the environment it will face”.   Parents have acquired information about the environment that may be useful to the child, and if they can translate that into paternal effects that change the offspring’s personality in a way that takes advantage of that information, they may enhance the offspring’s fitness (and by extension, their own chance of seeing grand-offspring).  A speculative example might go something like this:  parents experience a poor environment because they can’t find food, and this lack of food leads them to manipulate their offspring into having a more exploratory personality so that the offspring will have a greater chance of escaping the poor conditions of the immediate area to find food.  This would be a risky strategy, but the idea of being risk-prone in poor environments has a long history in behavioural ecology (especially in foraging, e.g. Stephens 1981).

The upside of this paper is that the connection between them is obvious and powerful, at least in hindsight .  As Thomas Huxley was said to have exclaimed upon learning of Darwin’s idea of natural selection, “how extremely stupid not to have thought of that”.  The link to paternal effects gives researchers working on personality one potential explanation for the variation they see and a paradigm to test experimentally, and will hopefully energize both literatures.  I was also under the impression from my readings that fitness differences in offspring phenotypes arising from paternal effects weren’t well explored (I’m open to correction on this!), so perhaps linking maternal effects to personality variation will provide more data on how these effects affect selection over generations. The only potential downside I can see is that personality research, so far, has been characterised by some confusion over terminology and methodology (which I will touch on in a later post);  it might take researchers in this area some time to sort out the best way to combine the two approaches fruitfully.  On the other hand, the most exciting moments in science generally emerge out of areas of confusion and doubt, so I hold out hope that exploring the effects of parental decisions on offspring personality will lead to great advances in our understanding of animal behaviour.

References:

Adam Reddon. Parental effects on animal personality (in press).  Behavioral Ecology.

Sasha R. X. Dall, Alasdair I. Houston, and John M. McNamara. The behavioural ecology of personality: consistent individual differences from an adaptive perspective. Ecology Letters, 7:734–739, 2004.

Anurag A. Agrawal, Christian Laforsch, and Ralph Tollrian. Transgenerational induction of defences in animals and plants. Nature, 401:60-63, 1999.

David W. Stephens. The logic of risk sensitive foraging preferences. Animal Behaviour, 29 (2):628–629, 1981.

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