Category: Evolutionary

Eusociality, Errors, and Behavioral Plasticity

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I encountered an error in E.O. Wilson’s The Social Conquest of Earth where the authors intended to assert an alternative to “kin selection” but instead repeated “multilevel selection,” which is precisely what the authors wanted to draw a distinction with. I am sympathetic, however, if for no other reason than I keep finding errors and issues with my own books and papers.

The critical technical discussion from Nature concerning the topic is available here. As technical discussion, the issues debated are fraught with details like how halictid bees appear to live socially, but are in fact solitary animals that co-exist in tunnel arrangements.

Despite the focus on “spring-loaded traits” as determiners for haplodiploid animals like bees and wasps, the problem of big-brained behavioral plasticity keeps coming up in Wilson’s book. Humanity is a pinnacle because of taming fire, because of the relative levels of energy available in animal flesh versus plant matter, and because of our ability to outrun prey over long distances (yes, our identity emerges from marathon running). But these are solutions that correlate with the rapid growth of our craniums.

So if behavioral plasticity is so very central to who we are, we are faced with an awfully complex problem in trying to simulate that behavior. We can expect that there must be phalanxes of genes involved in setting our developmental path (our nature and the substrate for our nurture). We should, indeed, expect that almost no cognitive capacity is governed by a small set of genes, and that all the relevant genes work in networks through polygeny, epistasis, and related effects (pleiotropy). And we can expect no easy answers as a result, except to assert that AI is exactly as hard as we should have expected, and progress will be inevitably slow in understanding the mind, the brain, and the way we interact.… Read the rest

Brain Size and Fitness

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An interesting data point taken from E.O. Wilson’s The Social Conquest of Earth: bigger brains mean better adaptation to new environments. That seems trivial in a way because it is part of the “folk” evolutionary theory that seems to flow naturally from the assumption of human uniqueness and our ostensive position at the apex of the evolutionary mountain.

But it doesn’t have to be that way. A very narrowly adapted organism could conceivably outcompete an intelligent generalist. The generalist requires massive physiological commitments to the energetic requirements of behavioral plasticity. The specialist is economical, efficient. So it has largely been an article of projective faith in folk theory that the human condition is explainable.

So it is always refreshing when I learn that there is empirical evidence that brings clarity to issues like this:

Big brains are hypothesized to enhance survival of animals by facilitating flexible cognitive responses that buffer individuals against environmental stresses. Although this theory receives partial support from the finding that brain size limits the capacity of animals to behaviourally respond to environmental challenges, the hypothesis that large brains are associated with reduced mortality has never been empirically tested. Using extensive information on avian adult mortality from natural populations, we show here that species with larger brains, relative to their body size, experience lower mortality than species with smaller brains, supporting the general importance of the cognitive buffer hypothesis in the evolution of large brains.

From Sol et. al., Big-brained birds survive better in nature. The emphasis in the title on “nature” suggests that perhaps they fail in captivity? Avian ennui?… Read the rest

Nesting and Spring-loaded Parasitism

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While enjoying your eggs, you should consider what primitive social insects do with theirs. Why? Because it may be essential to our understanding of social behavior and, hence, the notion of moral and ethical behavior. I’m reading Nowak, Tarnita, and E.O. Wilson’s 2010 article (and 43 pages of supporting materials), “The evolution of eusociality” from Nature (466/doi:10.1038/nature09205).

This is a contentious paper, I should add, because it postulates “multilevel selection” that operate at the group or species level. It is remarkable in several ways. First, it uses mathematical terminology to explain aspects if the theory of eusociality (literally: “good sociality” but, theoretically, the highest levels of social interaction) that we rarely see in papers on evolutionary theory. Specifically, ideas like “global updating” are introduced to explain why traditional methods of explaining eusociality are plagued by false assumptions about the spatial distribution of mating opportunities. I’m reminded of my own critique of the microevolution versus macroevolution distinction that pervades anti-evolution arguments: why would nature (or God for that matter) prevent hybridization of species while making it easy for genetic drift within a species? We either have a failure of imagination, the deliberate introduction of barriers to hybridization just to fool all of us or maintain a prescribed order, or we have a continuous transition from micro to macro effects (hint: there is actually no real distinction).

But back to eggs. E.O. Wilson and colleagues suggest that the earliest forms of sociality were among the parasitic wasps, like the Tarantula Hawk. Accumulate prey, stuff eggs into them, and then move on. Next, icky stuff happens in the prey. One allele change can turn the move on behavior off when the local environment is sufficiently rich, however, and then moms and offspring hang around in colonies together.… Read the rest

Creativity and Proximate Causation

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Combining aspects of the previous posts, what proximate mechanisms might be relevant to the notion of artistic fitness? Scott Barry Kauffman at www.creativitypost.com rounds up some of the most interesting recent research and thinking on this topic in his post, Must One Risk Madness to Achieve Genius?

Touching on work by luminaries like Susan Blackmore and others, Scott drives from personality assessment concepts down through the role of dopamine in trying to identify whether there is a spectrum of observable traits that are linked to creativity and artistic achievement.

Notable:

Daniel Nettle and Helen Clegg found that apophenia was positively related to a higher number of sexual partners for both men and women, and this relationship was explained by artistic creative activity. Similarly, in a more recent study conducted by Helen Cleff, Daniel Nettle, and Dorothy Miell, they found that more successful male artists (who are presumably higher in apophenia) had more sexual partners than less successful male artists.

Apophenia means seeing patterns in the environment where none may be present, a central theme in my second novel, Signals and Noise.

We can hypothesize also, based on the distribution from schizophrenia through schizotypy, through to “normal,” that there must be a large complement of interacting genes involved in these traits. This is supported by the evidence of genetic predispositions for schizophrenia, for instance, but also by the frustrating lack of success in identifying the genes that are involved.  This distribution may, in fact, be one of the most critical aspects of what it means to be human:

Were it not for those “disordered” genes, you wouldn’t have extremely creative, successful people.  Being in the absolute middle of every trait spectrum, not too extreme in any one direction, makes you balanced, but rather boring. 

… Read the rest

Sex and Error

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Just in time for Valentine’s Day, the introduction to my (foster) father’s 1991 Animal Behavior treatise, On the Role of Males (don’t worry guys, we get to expurgate genetic errors):

The value of males to a species has often been regarded as enigmatic. An all-female, parthenogenetic population has significant theoretical advantages over a population that must reproduce sexually. But if sexuality is to be advocated as highly advantageous to the species, the questions surrounding gender differentiation must not be confused with the questions concerning the value of sex. Two distinct genders are not necessary to engage sexual recombination. A broad array of hypotheses for the evolution and persistence of sexuality appears in Michod & Levin (1988), yet for all of the postulated arguments, males are unnecessary. While purpose cannot always be easily ascribed to a specific trait or behavior, the converse can be argued with confidence. The widespread, common existence of a specific trait, behavior or caste insures that the persistence of the attribute possesses some fundamental purpose.

Protracted demonstrations of competitive vigor are common in males, especially so in polygynous species. Darwin (1874) outlined in detail the virtual ubiquity of male aggressive “pugnacity” in animals, concluding that “It is incredible that all this should be purposeless” (1874, p. 615). The hypotheses to be argued here are threefold: (1) males are an auxiliary, relatively sacrificial sex of enhanced fragility, whose demonstrations of competitive vigor operate to expose, exaggerate, and expurgate significant gene error from the germline, (2) the aggressively competitive behavior of polygynous males is but one component of a hierarchy of genetic information assurance mechanisms that must be inevitably evolved, and (3) gene defect expurgation from the germline greatly accelerates the evolutionary optimization, and thus the competitiveness, of the species.

… Read the rest

Evolutionary Oneirology

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I was recently contacted by a startup that is developing a dream-recording app. The startup wants to automatically extract semantic relationships and correlate the narratives that dreamers type into their phones. I assume that the goal is to help the user try to understand their dreams. But why should we assume that dreams are understandable? We now know that waking cognition is unreliable, that meta-cognitive strategies influence decision making, that base rate fallacies are the norm, that perceptions are shaped by apophenia, that framing and language choices dominate decision-making under ambiguity, and that moral judgments are driven by impulse and feeling rather than any rational calculus.

Yet there are some remarkable consistencies about dream content that have led to elaborate theorization down through the ages. Dreams, by being cryptic, want to be explained. But the content of dreams, when sorted out, leads us less to Kerkule’s Rings or to Freud and Jung, and more to asking why there is so much anxiety present in dreams? The Evolutionary Theory of Dreaming by Finnish researcher Revonsuo tries to explain the overrepresentation of threats and fear in dreams by suggesting that the brain is engaged in a process of reliving conflict events as a form of implicit learning. Evidence in support of this theory includes experimental observations that threatening dreams increase in frequency for children who experienced trauma in childhood combined with the cross-cultural persistence of threatening dream content (and likely cross-species as anyone who has watched a cat twitch in deep sleep suspects). To date, however, the question of whether these dream cycles result in learning or improved responses to future conflict remains unanswered.

I turned down consulting for the startup because of time constraints, but the topic of dream anxiety comes back to me every few years when I startle out of one of those recurring dreams where I have not studied for the final exam and am desperately pawing through a sheaf of empty paper trying to find my notes.… Read the rest

Simulated Experimental Morality

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I’m deep in Steven Pinker’s The Better Angels of Nature: Why Violence Has Declined. It’s also only about the third book I’ve tried to read exclusively on the iPad, but I am finally getting used to the platform. The core thesis of Pinker’s book is something that I have been experimentally testing on people for several years: our moral facilities and decision-making are gradually improving. For Pinker, the thesis is built up elaborately from basic estimates of death rates due to war and homicide between non-state societies and state societies. It comes with an uncomfortable inversion of the nobility of the savage mind: primitive people had a lot to fight about and often did.

My first contact with the notion that morality is changing and improving was with Richard Dawkin’s observation in The God Delusion that most modern Westerners feel very uncomfortable with the fire bombing of Tokyo in World War II, the saturation bombing of Hanoi, nuclear attack against civilian populations, or treating people inhumanely based on race or ethnicity. Yet that wasn’t the case just decades ago. More moral drift can be seen in changing sentiments concerning the rights of gay people to marry. Experimentally, then, I would ask, over dinner or conversation, about simple moral trolley experiments and then move on to ask whether anyone would condone nuclear attack against civilian populations. There is always a first response of “no” to the latter, which reflects a gut moral sentiment, though a few people have agreed that it may be “permissible” (to use the language of these kinds of dilemmas) in response to a similar attack and when there may be “command and control assets” mixed into the attack area.… Read the rest