Blute Blog

Blute's blog about evolutionary theory: biological, sociocultural and gene-culture.

Tangled Trees?

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David Quammen book, The Tangled Tree: A Radical New History of Life was reviewed in Nature Aug. 2 by John Archibald (not incidentally the author of a book on symbiosis). It was also reviewed in the New York Times Book Review on Aug 14 by Erika Check Hayden under the title of “Uprooted”. On Aug 19, Quammen himself published an article in the New York Times Magazine titled “The Scientist Who Scrambled Darwin’s Tree of Life”.

Quammen’s book is largely about Carl Woese, the great pioneer of molecular phylogenetics, who in 1977 with coauthor Fox, made clear from their study of a component of ribosomes (protein factories in cells) that there are three not two domains of life – the Archaea in addition to Bacteria and organisms with nucleated cells like plants, animals, fungi and some unicellular organisms (Eukarya). Woese was apparently not a fan of Darwin – he commented to a prospective co-author of a book to be titled Beyond God and Darwin, “Jan, you accord Darwin so much more substance than the bastard deserves”.

Anyway, the theme of the reviews and article (and I assume of the book which I have not, or at least not yet read), is that life is better described as a “network”, a “tangled web”, or a “topiary” rather than Darwin’s tree because of the existence of horizontal i.e. lateral gene transfer (LGT ). LGT can take place by transformation (taking up DNA from the environment), transduction (a piece of host DNA carried to another organism by a virus), and conjugation (bacterial “sex” which is unidirectional). Unfortunately Hayden casually equates LGT with “swapping genes” which is exactly what it is not i.e. bidirectional rather than unidirectional. Not does its existence invalidate Darwin’s tree metaphor for evolution as these authors generally seem to think. Quammen’s article is illustrated with outrageous illustrations of what looks like an early hominid with a chicken’s head, one with a fish’s head, a human with what looks like a frog’s body between head and shoulders on top and lower legs and feet on the bottom. Perhaps we should not blame Quammen for these illustrations but the point is that because laterally transferred DNA is normally just a tiny part of the genomes of eukaryotes, the best metaphor I have seen is “trees with some cobwebs”. (In 2005 Liza Gross in PloS attributes this metaphor to Fan Ge and coauthors.)

Yet, once anisogamy (micro and macro gametes) have evolved, then sex again becomes unidirectional, i.e. from males or male functions to females or female functions. But that is unidirectional within a species – indeed the ability to interbreed after Mayr is what is most commonly said to define species boundaries. Of course Woese was right that we know very little of what went on in the early history of life. However, only if hybridization (sex between members of different species) were rampant in the Eukarya could Darwin’s trees truly be said to be entangled and despite the occasional case there is no evidence of that.

Written by Marion Blute

September 6, 2018 at 7:50 pm

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Autistics, Saints & Sinners: Ecological and Social Evolution

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It is common in evolutionary theory to distinguish between ecological and social evolution – evolution in interaction with the physical environment and other species versus that in interaction with other members of the same population or species. Of course in ecological evolution individuals compete with respect to some ecological phenomenon, but the difference is that it is a ‘scramble’ i.e. contact and interaction are not involved as they are in social evolution which includes phenomena such as kin selection, reciprocal altruism, various kinds of ‘contests’ involving contact and aggression, sexual selection etc.

A case might be made that there is actually something else and not just an absence of autistic characteristics at the other end of the autism spectrum. Most fundamentally, autism may reflect an excessive preoccupation with, and behaviour oriented towards the physical and ecological environments, “things” (which may include animals), at the cost of neglect of the social. V. K. Jaswal and N. Akhtar in an article on autism in Behavioral and Brain Sciences in June (see also their article in the New York Times, July 13) describe motor stereotypes but not other restricted and repetitive interests and activities. After all, it is no secret that Silicon valley is populated by austicish individuals preoccupied with their computers, programmes and gadgets. At the other end of the spectrum “saints” (Williams syndrome?) but also “sinners” (psychopaths) reflect an excessive preoccupation with, and behaviour oriented towards the social environment at the cost of neglect of the physical and ecological. The distinction between saints and sinners simply reflects whether the prevailing social orientation at that end of the hypothesized spectrum tends towards cooperative (altruistic – + or mutualistic + + interactions) versus conflict (selfish + – or spiteful – – ones). Individuals with Williams syndrome are exuberantly social including linguistically but in addition to lacking many ecologically-oriented cognitive skills such as spatial ones, lack social caution or fear. Of course, few individuals are at either of these social extremes, just as few are at the ecological or social extremes, most being somewhere closer to the middle.

Unfortunately, because the same ecological versus social distinction could be drawn about any selection process, none of this speaks to which one or ones of several possible selection processes – biological evolution, development, individual learning or sociocultural evolution is responsible for giving rise to autistics versus saints and/or sinners. Jaswal and Akhtar argue that autistics do not lack social motivation or interest. Instead, there may be a lack of ability or even adaptive or cultural reasons to avoid engaging in various forms of social interaction towards that end of the spectrum. It seems likely that genetics and/or development is involved but Jaswal and Akhtar make a good case that individual learning (“adaptation”) and/or cultural transmission are also part of the story.

Written by Marion Blute

September 3, 2018 at 2:33 pm

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Ridley (Continued)

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I do agree with Ridley that evolution is a general theory which is “not confined to genetic systems, but explains the way that virtually all of human culture changes” (p.2) and even that there is much evidence for culture-driven genetic change in the human species (Chapter 5). He describes the process most often as one of “trial and error”. I would be happier if he would make the metaphor explicit and say like trial and error because the latter is a psychological not a sociocultural process. Cultural or sociocultural evolution takes place by cultural transmission, variation and selection. I also agree that divisions of labour within individuals and specialization and trade between them (which incidentally need to be distinguished) are important in evolution, even biologically. They may be involved in the origin and evolution of gender differences and relations for example.

Ridley is not always consistent. For example, one of his most repetitive themes is that evolution is a “bottoms up process”. It is not always clear what he means by this – sometimes he seems to be reaching for what evolutionists call “populational thinking” i.e. evolution is not about individual anythings but about populations of such. Anyway, for a “bottoms up” guy I found it strange that he attributes variation and change in monogamy and polygamy in human history to its “beneficial effects on society” (chapter 5) and the popularity of “fictions” like the mind is because it “preserves the social order” (chapter 8) . Similarly, for one who opposes a “great man” theory of history and the importance commonly placed on the role of leaders in social change I found it strange that when ultimately using Hong Kong as the model of successful economic development in chapter 12, he attributes its success to the actions of a governor and later a financial secretary. Weren’t they leaders?

Nor should one take this book as an authoritative source on evolutionary processes.The prologue tells us that evolution is “incremental and gradual” (well, sometimes it is and sometimes it isn’t) and that the genome has “no master gene” (we don’t know whether it does or does not). Chapter 4 generally adopts Dawkins genes-eye view of biological evolution mostly avoiding problems such as all the cutting and pasting that goes on from transcription to post-translation and the fact that recombination in sexual species takes place within as well as between functional units. These mean that there is no genomic unit that is consistently reproduced or replicated, varies and evolves adaptively except, I suppose, base pairs. But somehow the idea of selfish base pairs is less captivating than selfish genes (although Ridley studiously avoids the “s” word, as does Dawkins himself these days).

Chapter 2 tells us that morality emerges spontaneously as individuals learn how to “get along” because they enjoy making other people happy! Given that the topic of altruistic (- +) and cooperative (+ +) as opposed to selfish (+ -) and spiteful (- -) relationships are among the most discussed in modern evolutionary theory, it is shocking that Ridley seems blissfully unaware of or uninterested in any of these ideas or research. In fact, this book even misses much discussed things which might be taken to support some of the views it expresses. One of the most discussed topics in recent years stemming from Maynard Smith and Szathmáry’s book The Major Transitions in Evolution has been transitions from prokaryotic cells to the eukaryotic, from single celled eukaryotes to the multicelled, from multicelled individuals to eusocial colonies and so on. Whatever theory one might favour of such transitions, they were undoubtedly bottoms-up events although the majority view is that they then transition to a top down process.

Oh well, I hope to have better luck with a couple of other books. Stay tuned but I will be slow – I have other responsibilities.

Written by Marion Blute

February 3, 2016 at 11:43 pm

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Matt Ridley, The Evolution of Everything: How New Ideas Emerge

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Over the holidays I began to read some recent books on cultural evolution. I began with Matt Ridley`s The Evolution of Everything: How New Ideas Emerge (HarperCollins 2015) because it has received a fair amount of attention. From what I had read and heard, I expected to both love and hate this book. I expected to love it because it is about the “general” (largely cultural) evolution of, well, EVERYTHING. Sandwiched between a prologue and an epilogue are 16 short chapters on the evolution of each of the universe, morality, life, genes, culture, the economy, technology, the mind, personality, education, population, leadership, government, religion, money and the internet!

To be sure, some of the chapters are not about what their titles would lead one to expect. Chapter 1 titled the evolution of the universe is not about the evolution of the universe at all. Instead it is about the history of western philosophy and science from Lucretius through Newton to Darwin told as a tale of more or less linear progress (but with many “swerves”) supposedly towards empiricism and atheism! Chapter 2 titled the evolution of life is not about the origins of life at all, instead it is about biological evolution in general, and more specifically, a pretty conventional account of how the concept of natural selection has largely won out over theories of design from pre-Darwinian natural theology including right up to the American legal wins over scientific creationism and intelligent design. It includes a few (I suspect) deliberately provocative claims such as that Darwin was really “rediscovering” Empedocles and Lucretius (p. 52)! Chapter 4 on the other hand titled the evolution of genes is about the origins of life. Chapter 8 on the evolution of the mind is not about the evolution of the mind at all. Instead it is about how the mind as opposed to the brain is a fiction. Oh well, enough of that.

Ridley’s real aim is to use evolutionary theory as a sort of coat tree on which to hang his neo-liberal or libertarian politics – in support of “private property, free trade, low taxes, limited government and freedom of the individual” while viewing the “modern state” as “liberal fascism” (p.243). Along the way he takes swipes at and not uncommonly pontificates at length against public health care, critics of genetic modification and fracking, the public funding of science, formal and particularly public education, patent systems, the belief that global inequality is increasing, government monopolies on money, fear of the consequences of climate change, that the financial crisis was caused by deregulation and so on. He even claims we could get rid of governments (p. 313) while from time to time piously championing “relief for the needy” (e.g. p. 243). To be sure he avoids the late 19th and early 20th century misuse of Darwinism to advocate for eugenics which came to be associated with forced sterilization, discrimination, and even genocide – in fact, in chapter 11, he explicitly disavows such views. Whether I agree or disagree with his politics is not the point. I resent claims that scientific theories can be used to answer questions of value as opposed to providing those responsible for making such decisions whether in the public, private, or voluntary sectors with useful information. No scientific theory has been more misused in such ways than Darwinism. Anyone who thinks science can answer questions of value rather than providing information to decision makers should read the great 19th century sociologist Max Weber’s wonderful essays on “science as a vocation” and “politics as a vocation”. (Continued)

Written by Marion Blute

February 3, 2016 at 11:40 pm

Should the genetic effects of environmental influences on phenotypes be paradoxical? It all depends.

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Ghalambor et. al. have presented evidence for a case in which they are – those exerting adaptive influences on phenotypes constrain subsequent adaptive genetic evolution while those exerting maladaptive influences facilitate it – phenomena that Merila, commenting in the same issue, describes as “perplexing”. But should that always be the case? I doubt it. Instead, it should all depend upon whether the case is one of “genes as followers” or of “genes as leaders” (West-Eberhard 2003, Schwander & Leimar 2011).

Consider a property such as body length, one for which there is genetic variation for phenotypic plasticity in a population. A novel environmental influence appears which pushes body length, previously below the optimum for whatever reason, up towards or to the optimum, a push also enabled by one of those genetic variants for length plasticity in the population. That genetic variant would subsequently be favoured by selection over others. Analogously, if the environmental influence pushed body length beyond the optimum, the genetic variant enabling that would subsequently be disfavoured by selection. There would be nothing paradoxical in such cases – an adaptive environmental influence results in subsequent evolution for a genetic alternative and a maladaptive one in subsequent evolution against a genetic alternative. These are so because they are cases of “genes as followers”. The environmental influence was a novel one, one not common in the history of the species and therefore not one the genetic alternative had evolved by natural selection to respond to positively or negatively respectively in these ways or to this degree. They would be cases of Gould & Vrba’s exaptation in the one case (or nonaptation in the other); just ones with the added complexity that the genes involved are those for a plastic response. (Gould & Vrba explicitly limited their discussion to “a state of being” rather than “a process” but nevertheless commented “we might consider the flexibility of phenotype characters as a primary enhancer of or damper upon future evolutionary change.”)

On the other hand, consider a “genes as leaders” case. If the environmental influence was not a novel one but was fairly common in the history of the species i.e. one which the genetic alternative had evolved to respond to in that way, the story would be different. Then an adaptive environmental influence on a phenotype would not result in any subsequent genetic evolution. Subsequent genetic evolution would be “constrained” because the genetic alternative would have done just what it had evolved by natural selection in the past to do. A maladaptive environmental influence on a phenotype however would “potentiate” or “facilitate” subsequent genetic evolution, selecting against the alternative permitting an environmental influence to have such an effect. The evidence Ghalambor et. al. present pertains to Trinidadian guppies (Poecilia reticulata) and their interaction or lack thereof with predatory cichlids. The experimental evidence presented is too complicated to summarize here, but given the results showing genetic constraining and facilitating effects of plasticity, the case obviously falls into this second “genes as leaders” category.

One might be inclined to protest that the concept of “the reaction norm” of a genetic alternative is sufficient to deal with all such phenomena. But it is important that the concept of a reaction norm not be used in such a way as to make all cases of evolution ones of “genes as leaders” by definition. Surely not all parts of the ranges of all norms of reaction have been tested by natural selection.

Ghalambor, Cameron K., Kim L. Hoke, Emily W. Ruell, Eva K. Fischer, David N. Reznick & Kimberly A. Hughes. 2015. Nature 525: Sept. 17, 372-375.

Gould, Stephen J. & Elisabeth S. Vrba. 1982. “Exaptation – a missing term in the science of form” Paleobiology 8(1) 4-15.

Merila, Juha. 2015. “Perplexing effects of phenotypic plasticity.” Nature 525: Sept. 17, 326-327.

Schwander, Tanja and Olof Leimar. 2011. “Genes as Leaders and Followers in Evolution.” Trends in Ecology and Evolution 26: 143-151.

West-Eberhard, Mary Jane. 2003. Developmental Plasticity and Evolution. Oxford: Oxford University Press.

Written by Marion Blute

November 4, 2015 at 2:02 pm

Remembering Werner Callebaut

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I was greatly saddened last month to be informed of the death of Werner Callebaut, Scientific Director of the Konrad Lorenz Institute, Editor-in-Chief of the journal Biological Theory published by Springer, Co-editor of the Vienna book series in Theoretical Biology published by MIT Press, and at the time of his death, President of the International Society for the History, Philosophy and Social Studies of Biology.

I have been trying to remember when I first met Werner. I clearly remember the actual conversation and I believe it probably was at the ISHPSSB (ishkakibble to insiders) meetings at Oaxaca, Mexico in 1999. At a coffee break he came up to me and said “you’re Marion Blute” and to my astonishment he began talking about a paper I had published on “Sociocultural Evolution: An Untried Theory” in Behavioral Science in 1979 based on part of my PhD thesis! I looked down at his name tag and exclaimed “Ah, Werner Callebaut”, your book is my favourite book in the philosophy of science” and it was. The book was Werner’s “Taking the Naturalistic Turn: How Real Philosophy of Science is Done” (1993). As a sociologist I had loved the way he had studied the philosophy of science (specifically of biology) by analyzing texts and interviewing theorists. The subtitle of his book had been a playful reference to debates over realism and relativism in philosophy and the title as a whole drew attention to the fact that he was studying science studies empirically – i.e. doing “real” philosophy. Unbeknownst to Werner, I long had the idea of replicating something of his study and finally got around to it a decade later with a graduate student, Paul Armstrong. We analyzed texts and interviewed some philosophers and others who had put forward general theories of the scientific process and published the results it in Perspectives on Science in 2011. One of my great satisfactions as an academic was the pleasure I gave Werner in talking about some extensions of that work at the ISH meeting in Cleveland in 2011. He sat in the front row with a big grin on his face – so pleased that his classic continued to bear fruit.

We had many interactions over the years both in person and via e-mail. We disagreed about systems theory but were both admirers of Donald Campbell. I remarked to him once that a lot of the conceptual analyses that philosophers of science engage in at ISHPSSB and elsewhere are scientifically useful and important and he agreed, adding that was why he was attempting to start a journal. I helped him out with Biological Theory, particularly in the early days, with some refereeing and other things, published a few pieces in the journal, and have remained on the editorial board and later the editorial advisory board to this day. I spent a pleasant afternoon at KLI after the Vienna meetings in 2003. In 2008 he wanted me to come and finish my book there, but with the books and papers I had accumulated for the work over the years, I decided it was impractical. In 2010 we discussed organizing a colloquia on the evolution of anisogamy (the foundations of the biological theory of gender differences and relations) which his board quickly approved but then we caught wind of a book to be published including articles by most of the people we would have invited so decided to scrap the project. Instead, I wrote an article on the topic and published it in Biological Theory in 2013.

This spring in the course of communicating about a book review he wanted me to do, he sent me a long e-mail about all the things he had been up to. He was so pleased that the new KLI building was more or less complete – at least the large, noisy crane had finally been dismantled! I read his article on scientific perspectivism that he sent with pleasure and true to his habit, which he said he had inherited from Donald Campbell, whatever I sent him he broadcast to anyone he thought would be interested. I was on the ISHPSSB nominations committee when Werner was nominated as President. Although enthusiastic, I wondered whether anyone could really handle managing KLI, the journal, the book series and the society all at once. But sure enough he assembled the biggest group of people to work on various committees for ISH that we have ever had. And this is the point. Werner was not only an accomplished intellectual in the traditional sense of broad-ranging interests, but also a great colleague and a superb networker. It is going to take a minimum of at least four people to replace him functionally, but he will never be replaced to his friends.

Written by Marion Blute

December 8, 2014 at 8:55 pm

At Harvard: Remembering Lewis Feuer

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I gave a lecture on “The evolutionary approach to history: sociocultural phylogenetics” to a workshop held weekly on History, Culture and Society organized by sociologist Orlando Patterson and historian Daniel Smail at Harvard last week. Speaking in a building named after William James reminded me of Lewis Feuer who did his PhD there under another great Harvard philosopher, Alfred North Whitehead. Lewis Feuer was the supervisor under which I began my PhD dissertation although he left for the University of Virginia before it was completed. So I thought I would post here my reminiscences of him that first appeared in our Sociology department’s newsletter in the fall of 2003, the year after he died at age 89.

“Many of us were saddened last year when we learned of the death of Lewis Feuer at the age of 89. He was a professor of sociology and taught theory and the sociology of science here from 1966 to 1976. An obituary summarizing his career was published in the New York Times on Nov. 30, 2002 and he previously published an autobiographical essay in Philosophy, History and Social Action so I will confine these remarks to some personal reminiscences. Lewis Feuer’s view of sociology was that it concerned the functioning of a universal human nature, one best understood by Freud and his heirs, under different social and historical conditions. If we were to substitute Darwin for Freud, this view would approximate that of contemporary sociobiologists (which he flirted with at one point). In addition to his numerous papers and books on philosophy, sociological theory, and the sociology of science, he is often remembered as one of a network of intellectuals loosely surrounding Commentary magazine which provided the intellectual foundations for the “new right ”in American politics.

The reality however was considerably more complex. Having been a Marxist in his youth, he had a love-hate relationship with radical students. He was fond of quoting Churchill to the effect (I paraphrase), “If you are not a socialist when young you have no heart, and if you are still a socialist when old you have no head.” In fact, with an academic wife, a daughter, and as an admirer of John Stewart Mill (whose Logic of the Moral Sciences he thought the best work on sociological methodology), he believed strongly in the equality of women. He always went out of his way to encourage women students, as well as those few third world students who found their way to the University of Toronto in those days. At the same time, he was prophetic in his deep conviction that the Soviet Union was an evil empire which would some day fall. He also believed that in our admiration of Mao, Fidel, Che, Fanon and so on, we were repeating the follies of his generation in their youth with respect to the Soviet Union. Of course, we thought that the experience of old fogies like him in talking about the forced collectivization of peasants or Stalin’s show trials was irrelevant to us and for our times. These debates were usually carried on with a twinkle in his eye but he had a temper too. We will never forget the day when a minor shoving match with one of our more radical graduate students ended up with the student falling through the glass door of the library. He was extremely proud that it was the student and not he that went through the door! What today would undoubtedly result in endless legalistic proceedings was probably resolved in those days by the chair telling Lewis to smarten up and the director of graduate studies telling the student to smarten up!

What I most remember was his scholarliness, his gratitude and his generosity. He loved the quality and depth of our library almost as much as the New York city library of his youth. Browsing in the stacks with Lewis was a learning experience. Instead of the newest shiniest book, he always reached for the oldest, dustiest volume that had been pushed to the back – seeking (and sometimes finding) some long-lost gem. A footnote to his career of which he was very proud was some detective work that led him to infer that at least one of the supposed letters from Marx to Darwin was actually written by Marx’s son-in-law, an inference that was later verified.

He always remembered kind treatment with gratitude. He was particularly grateful to the University of Vermont for having employed him in a time in which his political background may have made him unemployable elsewhere. In fact, his whole personality very much resembled the stubborn independence that we associate with Vermont’s political culture.

In addition to being my thesis supervisor until his move to Virginia, I worked for him as a research assistant one year. He pointed me to a data set on the scientific productivity of various nations. I figured out how to do the statistical analysis, including asking some questions that went beyond his initial one, did the analysis, and wrote the first draft of the paper. Despite the fact that he supplied the original data set and paid to have the work done, he generously insisted that I submit it to the American Sociological Review under my own name with just a footnote thanking him. His genuine pleasure when it was accepted could not have been greater if it had been his name on the paper.”

Written by Marion Blute

April 1, 2014 at 12:19 am

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You Tube Interview

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Link to video interview given at and posted by the International Summer School on Evolution, University of Lisbon, Summer 2013.

Written by Marion Blute

August 30, 2013 at 1:38 pm

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Major transitions in evolution

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Before going to Portugal to teach I attended the semi-annual meeting of the International Society for the history, philosophy and social studies of biology which was held this year in Montpellier, France. Along with Alejandro Rosas of the National University of Colombia, I organized and took part in a round table on the major transitions in evolution. Here are five questions I asked and what I had to say about them.

1) Should the topic be understood as “transitions” or additions i.e. as a change from one level of selection to another or as an addition of another level of selection?

I would argue for additions i.e. there is an evolving metapopulation of mitochondria in an evolving population of eukaryotic cells, an evolving metapopulation of cells in an evolving population of multicellular animals, an evolving metapopulation of modules in an evolving population of modular organisms and an evolving metapopulation of multicellular individuals in an evolving population of eusocial colonies etc. To employ a metaphor that has been used, such a point of view is neither deflationary nor inflationary but both simultaneously.

2) What is required for the emergence of an (additional) aggregate level of Darwinian individuals?

I agree with Godfrey-Smith that it is the emergence of entities subject to evolution by natural selection. However, rather than B, G and I (i.e. bottleneck, germ line and integration) I would argue that what is required is an additional aggregate developmental cycle, including but not restricted to a life cycle. That in turn requires a minimum of a complementary pair of life history strategies, each of which constructs the ecological conditions that favour, and in the transition or addition, come to induce (or whatever predicts them comes to induce) the other. So niche construction or eco-evolutionary dynamics are central. For example in a renewable environment, a cycle of plentiful resources which favour (and come to induce) growth, which constructs scarce resources, which favour (and come to induce) maintenance in the form of diapause for example, which constructs plentiful resources again – is a developmental cycle subject to selection, albeit not a life cycle, i.e. not progeneration in Griesemer’s sense.

3) Queller’s “fraternal” or what Nowak’s group has called the “staying together” case: is it attributable to kinship or ecology?

Staying together is better described as kin facilitated, because it most fundamentally requires an ecological explanation. If it’s hot and you need to lose heat it is better to be apart, but if it’s cold and you need to retain heat it is better to be together; if parasites are the greatest threat it is probably better to be apart, but if predators are the greatest threat it is probably better to be together; and so on. Such advantages of being small or large and there are many others, pertain to the advantages of having a proportionately greater ratio of surface area to volume for the small relative to the large or volume to surface area for the large relative to the small. The point is that kinship can facilitate either staying together or going apart depending upon ecological conditions. This implies that in the recent great debate between E. O. Wilson and (almost) everyone else in which he emphasizes the importance of ecology over kinship (defensible nests for eusociality for example), I have concluded that he is more right than wrong, including his 2012 description of genomes as chimeric (selected for at different levels) albeit not about some of the more fanciful extensions e.g. that humans are a eusocial species.

On the “staying together” case too, it is worth noting that a new life cycle it is not typically just a “staying together” but a cyclical staying together and going apart. For example cells in a multicellular organism reproducing asexually by multicellular propagules do not just “stay together” – they cyclically stay together and go apart – the propagules go apart from each other and if there are distinct reproductive and somatic cells, the reproductive ones go apart from the somatic.

4) Queller’s “egalitarian” or what Nowak’s group has called the “coming together” case: are sexual families additional Darwinian individuals and if so, what role do cooperation and conflict play in them?

Like Michod, I think sexual families likely are additional Darwinian individuals i.e. there is an evolving metapopulation of individuals in an evolving population of sexual families. However, sexual families too are not just a coming together but a cyclical coming together (fertilization) and going apart (meiosis) in haploids with a zygotic meiosis, or a going apart and coming together in diploids with a gametic meiosis. On the role of cooperation and conflict in these comings and goings, assuming an equal allocation to both at equilibrium, the simplest possibilities would be that in haploids for example, they either come together in conflict and go apart in cooperation, or come together in cooperation and go apart in conflict. The former (conflict then cooperation case) is implied by the traditional PBS theory of the evolution of anisogamy in which at fertilization, microgametes are viewed as reproductive parasites of macrogametes, but then recombination at meiosis is assumed, as it traditionally has been, to be mutually advantageous for whatever reason. The latter (cooperation then conflict case) is implied by the “market” or “trade” theory which Noë and Hammerstein originally suggested and I more recently have revived, and which might then be taken to imply that meiosis is a matter of conflict with genetic recombination a side effect of the mechanics of gene conversion rather than gene conversion a side effect of the mechanics of recombination. In a stunning recent paper, Laurence Hurst and some colleagues from China (Yang et. al. 2012) employed next generation sequencing techniques to determine that the great majority of recombination events in Arabidopsis (over 90% and probably nearer 99%) are gene conversion events. On the other hand, whether they come together in conflict or in cooperation, it is still possible that they go apart in cooperation – sexual families having discovered the advantages of risk reduction under uncertainty (like investing in index funds or dollar cost averaging rather than trying to pick stocks or time markets). What is unlikely I think is that both are a matter of conflict which would not pay back the two-fold cost of sex and would hence be unlikely to out compete asexuals.

5) Can it be said, as Bourke (2011) believes for example, that egalitarian or coming together transitions (or additions) require a “shared reproductive fate.”?

I doubt it. Assuming he means being confined inside the same ‘skin’ as say a vertically-transmitted symbiont, then I doubt it is necessary. I don’t know a lot about multispecies communities but occasional casual mutually positive interactions rather than regular cyclical ones between members of different species for example would not be sufficient. Nor do I think that “differential persistence” is sufficient – a slab of a hardwood persists longer than one of a softwood but are hardly Darwinian individuals (unless viewed as cultural ones). But I think it likely that theorists like Watson and Bouchard are still generally right. Some interspecific “coming togethers and going aparts” without remaining confined in the same ‘skin’ are likely systematic enough to indeed constitute additional Darwinian individuals. Positively non-additive fitness interactions at some stage at least sufficiently large enough to compensate for any negatively non-additive ones which may obtain at another would be a key requirement.

Written by Marion Blute

August 7, 2013 at 9:49 pm

Photos from Lisbon

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Instructors at the International Summer School on Evolution, at the Applied Evolutionary Epistemology Lab in the Faculty of Science, University of Lisbon. Left to to right, Derek Turner, Michael Ruse, Frédéric Bouchard,    , Fiona Jordan, Nathalie Gontier, Marion Blute, Ilya Tëmkin, Luis Villarreal, Frietson Galis, Emanuele Serrelli.

Thanks to Nathalie and her staff for their hospitality and the pics!


My class.


Written by Marion Blute

August 6, 2013 at 8:56 pm