tag:blogger.com,1999:blog-4989966954446423670.post8673912574043502106..comments2024-03-02T00:44:55.128-08:00Comments on Pleiotropy: The trouble over inclusive fitness theory and eusocialityBjørn Østmanhttp://www.blogger.com/profile/08859177313382114917noreply@blogger.comBlogger14125tag:blogger.com,1999:blog-4989966954446423670.post-54791066744330012882013-04-18T07:04:37.975-07:002013-04-18T07:04:37.975-07:00I read it. Thanks for your comments.
Link to the ...I read it. Thanks for your comments.<br /><br />Link to the 2012 paper: <a href="http://www.pnas.org/content/109/5/1595" rel="nofollow">Experimental evolution of multicellularity</a>.Bjørn Østmanhttps://www.blogger.com/profile/08859177313382114917noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-47954466203428604752013-04-18T02:57:48.807-07:002013-04-18T02:57:48.807-07:00Probably no one is reading this since this is two ...Probably no one is reading this since this is two years old now, but I thought I'd mention two things...<br /><br />First, to James, a 2012 research shows that yeast can be induced to form multicellular colonies that divide by apoptosis of some of the members, with a selection pressure lasting just 60 days. This is stronger than merely foregoing reproduction, in my opinion. So that tells me this process may not be quite as rare as all that.<br /><br />Second, when talking about communication and sociality, one should not neglect the handicap principle, even if it is not enough in itself to explain eusociality. I studied under Zahavi and while I disagree with his assessment of the scope of what HP explains (who isn't in love with his own theory, right?), I still think that it clearly shows signaling cannot be reliable without an associated cost. This may be relevant insofar as you focus on signaling as a component in this question.Polymeronhttps://www.blogger.com/profile/11293668192822058995noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-65956647120725456092011-03-30T06:21:50.701-07:002011-03-30T06:21:50.701-07:00Thanks, Rich, for the reference: The genetical the...Thanks, Rich, for the reference: <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2011.02236.x/full" rel="nofollow">The genetical theory of kin selection</a>. Stuart West is a coauthor, and he's one of the prominent spokesmen for kin selection (and one of the 137).Bjørn Østmanhttps://www.blogger.com/profile/08859177313382114917noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-61330703471677064262011-03-29T19:16:50.703-07:002011-03-29T19:16:50.703-07:00There is a new paper by Gardner et al., in the &qu...There is a new paper by Gardner et al., in the "early view" section of Journal of Evolutionary Biology. It is called "The genetical view of kin selection" and they discuss numerous issues and misconceptions of kin selection, showing that it is a robust model. They rebut some of the claims of Nowak et al., and many others, as well as tackle the relationship between kin selection vs. group selection. It is one of the more interesting papers that I've read in a long time. Very clear and well-writtenrich lawlerhttps://www.blogger.com/profile/13353965284524429553noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-38273537079243711552011-03-26T06:27:19.353-07:002011-03-26T06:27:19.353-07:00Yeah, slime molds (M. plasmodium -- never would ha...Yeah, slime molds (<i>M. plasmodium</i> -- never would have remembered the technical name in a million years, but "slime mold" is easy to remember!) were the only example I was previously aware of that resembled what we might imagine a precursor of multicellular life would look like. The <i>C. vulgaris</i> example is really cool, especially because they induced it in laboratory conditions.James Sweethttps://www.blogger.com/profile/17212877636980569324noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-4114306713885334092011-03-25T15:12:27.038-07:002011-03-25T15:12:27.038-07:00They are also cases of organisms that produce frui...They are also cases of organisms that produce fruiting bodies in which only a fraction of the cells will benefit in the end. It might be <i>Myxomycete plasmodium</i>...Bjørn Østmanhttps://www.blogger.com/profile/08859177313382114917noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-11866060837664790062011-03-25T13:20:49.172-07:002011-03-25T13:20:49.172-07:00Okay, I read the comments of the C. vulgaris post,...Okay, I read the comments of the <i>C. vulgaris</i> post, and I see that you already covered that in your conversation with the anonymous I'm-not-a-Creationist. (The "It leads me to be open-minded" quote was indeed pretty hilarious)<br /><br />It is interesting that my previous comment was verging on (what I did not know was) a common IDist talking point, but the only point I was making is that the evolution of true multicellularity -- not a multicellular colony, but the type where some of the cells intentionally forgo reproduction -- is likely a rare event.<br /><br />If IDiots weren't such idiots, that could almost be their long sought-after legitimate contribution to real science. If systems identified by IDists as "irreducibly complex" tend to correlate with molecular evidence showing that the system in question evolved only once, then I suppose one could make an argument that the "theory of ID" was useful as a shortcut for sifting morphological correlations for whether they were the result of convergent evolution or shared ancestry. Unfortunately for their IDiotic pursuit, there seems to be no such correlation. The eye? Are you kidding me?!? I admit to a layperson the eye initially seems pretty damn unlikely to have evolved by chance, but, forgetting even the molecular evidence, there are distinct morphological clues that the eye has developed over and over and over again... not a good choice to make an argument for irreducible complexity!<br /><br />Damn, I'm rambling now. Nevermind.James Sweethttps://www.blogger.com/profile/17212877636980569324noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-58514152444476924992011-03-25T12:42:41.257-07:002011-03-25T12:42:41.257-07:00Re: Chlorella vulgaris -- fascinating! I was awar...Re: <i>Chlorella vulgaris</i> -- fascinating! I was aware of slime molds, but if that were the only example one could argue that perhaps the shared ancestor between ourselves and slime molds was a multicellular precursor.<br /><br />One thing bothers me about decreeing the mutant <i>C. vulgaris</i> colonies to be true "multicellular organisms" -- do any of the cells forgo reproduction so that the other cells might reproduce? I only read your post, not the paper, but it's looking like not? It seems that the individual mutant <i>C. vulgaris</i> cells aren't even behaving altruistically, let alone forgoing personal reproduction for the sake of the macro-"organism".James Sweethttps://www.blogger.com/profile/17212877636980569324noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-61245550278220330652011-03-25T07:55:24.018-07:002011-03-25T07:55:24.018-07:00I don't know good literature for laypeople on ...I don't know good literature for laypeople on group selection, but I can recommend scientific papers on group game theory experiments (Nowak has written may HIntze some, e.g. http://arxiv.org/abs/1006.2903 http://arxiv.org/abs/1012.0276 http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1000948). Also, you might want to check out David Sloan Wilson's blog on <a href="http://scienceblogs.com/evolution/" rel="nofollow">ScienceBlogs</a>.Bjørn Østmanhttps://www.blogger.com/profile/08859177313382114917noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-51280404317286516672011-03-25T07:16:02.340-07:002011-03-25T07:16:02.340-07:00James, there are examples of observations of clona...James, there are examples of observations of clonal colonies forming multicellular organisms. I wrote about one, <a href="http://pleion.blogspot.com/2008/11/watching-multicellularity-evolve-before.html" rel="nofollow"><i>Chlorella vulgaris</i></a>, a while ago. I don't think we can conclude that it only happened once.Bjørn Østmanhttps://www.blogger.com/profile/08859177313382114917noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-24721320601842213942011-03-25T06:17:25.854-07:002011-03-25T06:17:25.854-07:00Actually, the Wikipedia article on group selection...Actually, the Wikipedia article on group selection has helped tremendously already. I totally buy the haystack model, but of course that really only has an analog in nature in the case of things like viruses, parasites, and, arguably, multi-cellular organisms (if you look at each cell as the individual and each organism as the haystack, that is). The "trait groups" thing is intriguing, but the Wikipedia description of that is somewhat poorly written and I am having difficulty telling how brittle the mathematics are (i.e. do all the parameters have to be "just right" in order for this to work, or does it contribute across a range of parameters?)<br /><br />I do not have <i>nearly</i> enough of a grasp on the technicalities of eusociality to have any sort of opinion on whether kin selection or group selection (or some mix of the two) seems the more plausible explanation. In fact, every time I read about the evolution eusociality, at some point I get really <i>really</i> confused :)<br /><br />One more note about the comment I made about multi-cellular organisms... When I read "12 Misconceptions" yesterday, I was surprised that no mention of this idea was made in the entry about kin selection as applied to clones. Dawkins makes convincing arguments that while kin selection could in theory cause a clone to behave altruistically towards all of its clones, the sequence of events to facilitate this would be pretty unlikely. He then hedges by pointing out that maybe this has happened in a particular aphid species. I feel another hedge was called for, in that we can fairly safely say that something <i>exactly</i> like this happened in the evolution of multi-cellularity: A clonal population evolved unbounded altruism towards the in-group which was virtually guaranteed to be clones. The fact that this appears to have only happened <i>once</i> seems to support the idea that such an event would be quite rare, and so I think this is "the exception that proves the rule" in the original sense of the cliche. Maybe I'm making some horrible layperson mental error though :)James Sweethttps://www.blogger.com/profile/17212877636980569324noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-41590348582375031802011-03-25T05:53:31.611-07:002011-03-25T05:53:31.611-07:00I read the "12 Misconceptions" yesterday...I read the "12 Misconceptions" yesterday, definitely enjoyed it. I felt some of the misconceptions were so obvious that it boggles the mind that serious thinkers missed it; but then again it also cleared up a number of things for me, so who knows where our blind spots are?<br /><br />Bjørn, do you have any recommendations for lay-accessible literature that would describe how group selection might work? I have difficulty envisioning how it could create lasting evolutionary change -- but this is probably because I don't understand it. I'm certainly not going to be tackling any of the deep mathematics, but I'd like to have an intuitive understanding of the arguments being made...James Sweethttps://www.blogger.com/profile/17212877636980569324noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-86147732857263817262011-03-25T03:53:22.040-07:002011-03-25T03:53:22.040-07:00Aaack! Gomen nasai! I have no idea why that doub...Aaack! Gomen nasai! I have no idea why that double posted (a ra ra ra..)yokohamamamahttps://www.blogger.com/profile/17098212549844656652noreply@blogger.comtag:blogger.com,1999:blog-4989966954446423670.post-73732543796619773252011-03-24T23:16:27.620-07:002011-03-24T23:16:27.620-07:00Jerry Coyne's second post on this includes a r...Jerry Coyne's second post on this includes a reply from Dawkins, which itself includes a link to Dawkins' 12 Misunderstandings of Kin Selection". I've downloaded, and will read as carefully as I can-- when Dawkins undertakes to clear up misconceptions, he usually does so pretty thoroughly . Have you read it? I'd be interested in your take on that, too.<br /><br />Didn't know that about the Templeton funding--or about the silliness of "the evolutionary biology of a world created by god". Seriously?yokohamamamahttps://www.blogger.com/profile/17098212549844656652noreply@blogger.com