First a general overview & appraisal of the book, and after that there’s a fairly lengthy section with quotes and paraphrases of nuggets of wisdom I want to keep on record, and those could be interesting for you too.

For starters, the summary on the back: “In this book, Russell Powell investigates whether we can use the patterns and processes of convergent evolution to make inferences about universal laws of life, on Earth and elsewhere. Weaving together disparate philosophical and empirical threads, Powell offers the first detailed analysis of the interplay between contingency and convergence in macroevolution, as it relates to both complex life in general and cognitively complex life in particular. If the evolution of mind is not a historical accident, the product of convergence rather than contingency, then, Powell asks, is mind likely to be an evolutionarily important feature of any living world?”

Or, as the MIT website states it in short: “Can we can use the patterns and processes of convergent evolution to make inferences about universal laws of life, on Earth and elsewhere?”

The book doesn’t presuppose a lot of working knowledge: Powell takes care to explain all the concepts and the history of science & philosophy one needs to understand his arguments. As such it is perfectly self-contained, BUT, mind you: this is hardcore stuff, it is not a popular science book at all. It has 280 pages of carefully and tightly argued text, there’s not a lot of redundancy, not even on the sentence level, and as such keeping a search engine at hand while reading this is no luxury.

There’s also 20 pages of biographical notes, and Powell has read wide and far on all kinds of matters to make his case: both evolutionary science in the biological sense, as well as evolutionary accounts of developmental psychology and sociology – of the kind I reviewed earlier with Tomasello’s Becoming Human: A Theory of Ontogeny, and science and philosophy on Umweltian cognition & phenomenology. There are also important chapters on invertebrate cognition, diving into the latest, cutting edge research on cephalopod minds and the surprising capacities of bees and other critters. It truly is an interdisciplinary intellectual feast, and I learned a lot.

While some might say this book at times could be to detailed for the layperson, I nevertheless – being a layperson – enjoyed it from cover to cover. I thought it was a delight being taken on an intellectual adventure that challenged my brain. Admittedly I’m not fully part of the target audience, but seeing Powell argue so meticulously was a treat in and of itself, and for scholars of evolutionary biology or professional theorists of mind the pleasure will only be bigger. 

The book is divided into two parts, and I want to stress the different nature of part 1 and part 2: some readers could still find much of worth in part 2, even if they aren’t interested in all the details of part 1, and vice versa.

The first part starts with a chapter on the need for biotheoretical input in matters of cosmic astrobiology because of observer selection biases, and afterwards examines Gouldian concepts of convergent & contingent evolution in the broad sense, focusing on the evolution of bodies. Powell does what everybody that takes science seriously should do: he examines & tries to define the meaning of the concepts – something that is sadly too easily glossed over time and time again. As such this first half is also part critical reading of Stephen Jay Gould and other evolutionary theorists.

The second part zooms in on minds, and starts with an extremely interesting investigation of sensory modalities in various animals, as sensing your surroundings is crucial to develop a mind. It continues with a discussion of how animals perceive their surroundings and themselves in those surroundings, and what that means for the possible emergence of minds. The last two chapters then look at possible evidence on how minds – other than the minds in the brains of terrestrial vertebrates – could emerge from neuroanatomy and the convergent evolution of bilateral brains and other types of neural clusters, and at evidence from behavior – from cephalods and arthropods, as I referred to above.

The stunning coda makes the jump from minds to full fledged human-like culture, and offers a few cents on the Fermi paradox – a paradox well-known to the scifi readers of this blog.

Although Powell dares to make numerous pretty definitive claims, he also shows a lot of humility and restraint: “when all is said and done, most of the landscape will remain uncharted, and the mystery of mind will remain.”

The excellent and always informative blog The Inquisitive Biologist has already written a splendid in-depth account of the book here, especially of the first part, so be sure to read that first if you have any inclination to read it. I will also defer from further trying to summarize the book, as that review has done most of the work already.  [update June 2022: Also Jeroen Admiraal, a biologist too, wrote a very accessible summary of the book on his blog, again with a focus on the first part.]

To end this part of the review, let me be loud and clear about it: this book is highly, highly recommended, easily a 5-star read, something rare indeed. I have already ordered 2018’s The Evolution of Moral Progress: A Biocultural Theory by Allen Buchanan and Powell, I’m very much looking forward to reading that, and I will be on the lookout for whatever Powell publishes next.

[update November 2021: The author today goes by the name of Rachell Powell.]


I will leave you with some of the nuggets I’ve learned while reading Contingency and Convergence : Toward a Cosmic Biology of Body and Mind. The usual caveats apply: these nuggets are not a summary at all, and are not intended as a representative sample of the actual content of the book. They are just here as a reminder for myself, and maybe some of them will delight you too. They might, however, show a wee bit of the rich, broad scope of Powell’s book – that is, if you factor in this reader’s selection bias.

> ‘Contingent’ is not the same as ‘unpredictable’ or ‘nonrepeatable’.

> We cannot observe minds. What we can observe are brains and behavior (“the causal signatures of minds in the world”).

> Like I already learned from Rosenberg’s brilliant book Darwinian Reductionism, biology is an historical science. It is not law-based, like the study of stars. Powell’s book is a cautious attempt to see how much biology on Earth could learn us about possible biological laws in the larger cosmos.

> Carl Woese and his collaborators’ work implies that “there was no single, discrete common ancestor of all extant life. Instead, there was a single ancestral communal population. On this view, proper “tree-like” evolution, with clean lines of vertical descent, would not come until later in life’s story.”

> Viz. the Copernican notion that the universe must be teeming with complex intelligent life, similar to our own: “We cannot infer from what did happen to what had to happen purely on the basis of statistics.”

> Molten metal planet cores are important as they support magnetospheres, “which deflect solar winds that would otherwise deplete atmospheres, as appears to have doomed the early Mars”.

> Extinction events (stochastic or pseudo-stochastic) “cut deeply into the possibility of a law-like shape of life.”

> “lineages do not get better at not going extinct over time as one might expect they would if evolution were a gradual optimizing process”

> “Also likely to be universal is the non-meritorious culling power of mass extinctions. Life will tend to evolve on geophysically dynamic planets, and the downside of living on a geophysically dynamic planet is that it comes with the occasional mass perturbation due to volcanism, tectonic movement, asteroid impact, climatic change, and the like.”

> “not only are the concepts of contingency and predictability severable, they describe entirely different categories of thing: metaphysical states of the universe, on the one hand, and knowledge states about metaphysical states of the universe, on the other. Although determinism and predictability bear important relations to one another, it is also easy to see how the two come apart and why their conflation is problematic. For instance, chaotic dynamical systems are deterministic, yet they are in principle unpredictable; quantum mechanical systems are irreducibly indeterministic, yet they support the greatest predictive precision ever achieved by a human science. Even comparatively simple deterministic system will support prediction only to the extent that the laws of nature can be know, present states ascertained, and future states computed by the cognizer in question. The “n-body problem” (…) shows that even for Newtonian systems involving only three bodies (…) attempts to derive future states of the system can be intractable. Thus, whether the universe or some relevant subset of it is deterministic is a metaphysical question that is wholly distinct from the question of whether future states can be predicted by any given cognizer. It follows that whether macroevolution is radically contingent is a metaphysical question that is decidedly not determined by the knowledge state of any observer.” (It is not prediction or not but causal structure that makes contingent, contingency has to do with metaphysics, not with epistemology.)

> “Biological indeterminism is not, substantively speaking, an implausible position, as irreducibly chancy events may very well “percolate up” from the quantum level to affect evolutionary trajectories. This percolation may occur, for example, through proton tunneling that affects which mutations arise or in what order they do so. Or it may occur through quantum alterations of microscopic initial conditions on which chaotic geophysical systems (such as weather, climate, tectonics, etc.) are sensitively dependent, with chaotic dynamics magnifying these events to the point that they influence large-scale selective environments.” (But as far as I can grasp, this is not an (theoretical) argument against biological determinism as it is generally understood, in the causal sense of the word.)

> “The standing humanoid epidemic in science fiction is not due solely to the limitations of imagination or the pragmatic demands of cinema. Nor can it be chalked up to an ignorance of the disparate body plans in which terrestrial intelligence has arisen. Rather, there is predilection to infer from what did happen in evolution to what had to happen, and this tendency is underwritten by the bundling bias.”

> There are single-celled eukaryotes that have camera eyes, sculpted out of subcellular organelles!

> Light, sound and electromagnetic fields are types of waveform energy that can carry “ecologically useful information about the distribution of objects and their properties”. “Other energy stimuli, such as chemical gradients that serve as the basis of olfaction, do not carry information that can underwrite a three-dimensional perceptual world that supports sophisticated locomotion, navigation, predation, and other cognitive-mediated behaviors. (…) olfaction is informationally impoverished when it comes to forming real-time images of objects that comprise scenes.”

> Echolocation (bats, thooted whales) and electrolocation (certain fish) can be considered to be equivalent to vision: they allow the animal a similar real-time, 3D, fine-grained image of their surroundings, and they even allow for cross-modal recognition in species that can also see.

> “it is chemistry rather than physics that distinguishes biology from technology.” (quoted from Land and Nilsson)

> It’s obvious, but bears repeating: there are numerous organisms that transfer information through other means than neurons. Also plants, unicellular eukaryotes and bacteria all “exhibit functional analogs to memory and learning that are decoupled from metabolism.”

> It is very difficult to define ‘neuron’. (as pointed out by William Kristan)

> Brains integrate vast amounts of information by virtue of recursive interchanges.

> There is, so far, “at least one study showing that ants pass the mirror self-recognition test.” That might say something about that test, or about self-recognition being not the same as self-awareness “in a thick narrativistic sense”. Either way, remarkable.

> It’s crazy what bees can do. Much more than foraging dances. Seriously, look into the latest research on bee cognition. Like here, and here, and here.

> “In short, emotions are action-tendencies that include a cognitive appraisal of some internally modeled state of affairs in the world and an accompanying somatic state or “feeling,” which together generate appropriate action (such as approach or avoidance). Actions like visual search would arguably be impossible without affective valences being attached to perceived objects and outcomes. Neuroscientist Antonio Damasio argues that action is often guided by the “fainter image of an ’emotional’ body state, without having to reenact it in the body proper.” Damasio conjectures that these affective markers, or “as-if” emotional simulations, are trained up over the course of ontogeny and permit rapid decision-making by bypassing the slow and energetically costly experience of a full-blown emotional state. These “as-if” feelings occur outside of attention or conscious awareness.”  One could hence argue insects must have “affective capacities.” (On a personal note, as I observe my children (and myself) growing a bit older, there is something to be said for that ontogenetic shift from full-blown emotional states to fainter images of those states.)

> The evolution of human-grade technological capacities – a cumulative culture – is based on a “formidable suite of contingencies” that “have been largely overlooked, and as a result the fraction of evolutionary histories that are expected to lead to robust technological civilizations has been overestimated.”

> Morals and constructed learning environments can be considered social technologies. (This part of the book ties in to the ethical part of Tomasello’s Becoming Human, which I already linked to at the very beginning.)

> Nor symbolic culture, nor language, nor morality by themselves or taken together necessarily lead to a cumulative culture as we are living it since about 40,000 years or so, again amplified by the agricultural revolution, and the industrial and scientific revolutions.

> “In a break from nearly all of human history, technologies that are ubiquitous today bear essentially no resemblance to technologies that are hundreds or thousands, let alone millions, of years old.” Powell doesn’t say this, but might I end with pointing at the potential disrupting nature of this remarkable fact? Others have written about small aspects of it, like Bakker and Auerbach, and it’s obviously ironic that because of it, we humans also contribute to the planetary geophysically dynamism Powell wrote about in one of the quotes above.


Click here for an index of my non-fiction or art book reviews. Here‘s an index of my longer fiction reviews of a more scholarly & philosophical nature.

The author index includes my fiction reviews, and here are my favorite lists – including a list of favorite non-fiction.




  1. Thanks for the review, I‘ll take a look at it (though I have to confess that I’m swamped with non-fiction reads these days).
    Will we see some day little, green aliens; or are octopuses or a Wang‘s carpet far more probable?

    Liked by 2 people

  2. This sounds very interesting! Also very demanding, in how much concentration it asks. Those quotes are quite chewy. These are some of the most fundamental questions about evolution that almost every biology student asks the professor at one time (guilty) and professor finds it hard to come up with an answer. (for Greg Egan’s Wang Carpets I suggest his amazing novel Diaspora)

    Liked by 1 person

  3. This goes automatically on my TBR – sounds fascinating!
    Thanks for the recommendation, Bart!

    Liked by 1 person

    • It reconfirmed my belief in the mystery and wonder that is all that lives. Not that that belief needed reconfirmation, but the more evidence, the merrier. What maybe struck me most about convergent evolution was a picture drawing parallels between the filter system of a whale and a flamingo, that neared an epiphany.

      I googled a bit, and here’s a version of it online: (But don’t get your hopes up of also getting an epiphany, I guess it was something totally ideosyncratic.) It’s striking because whales come from mammals and birds from reptiles, and there’s also the size difference, etc.

      Liked by 1 person

      • I’ll check it out. I think for me the moment you describe was when I learned about the evolution of an eye (the cephalopod case). I’m very curious about the mind/sentience part of this book!

        Liked by 1 person

        • Powell writes about convergent eye evolution too, in cephalods, arthropods and even single cell organisms.

          Obviously he doesn’t solve the riddles of sentience/mind, but he poses a lot of great questions, and he clearly ties perception while moving about to sentience, I hadn’t thought of it that way. (Sentience as real time input processing.)

          Liked by 1 person

  4. Well, damn. This has to go onto the ‘to-read’ list. It sounds like a more academic version of a recently published book called “A zoologists guide to the universe”. This, however, sounds more interesting.

    Liked by 1 person

    • Yes, it’s very academic. I didn’t know about that book, thanks. It seems to be about the exact same thing, but on first time a bit of a lighter affair indeed. Seems more like an overview of what might be possible given other evolutionary contingencies. I might have to read it too. Might be different enough. But I doubt it will be so thorough & rigorous as Powell’s book. Anyhow, thanks again, I appreciate the pointer a lot!


    • I’ve just read the NYT review. It seems something that in part would annoy me, as for lack of evidence in some cases, and the fact that he seems to gloss over things like alien technology as ‘inevitable’.


  5. Aonghus Fallon

    ‘What were the evolutionary mechanisms that made those aliens evolve in that way? Why do they form the patterns?’

    Precisely! I had to re-read this story again to clarify my thoughts about it. It stands up pretty well, but yeah – what were the evolutionary mechanisms? Egan postulates changes in climate and fluctuations in the ocean’s make-up, things that occurred millennia before, but it does seem improbable something so complex would evolve naturally, especially when that complexity doesn’t serve any clear purpose.

    In fairness, the story is really about different factions with competing ideologies and how the discovery impacts on those ideologies rather than the probability of such creatures ever existing.

    Liked by 1 person

    • Thanks for clearing that up! What you write is what I expected, Egan didn’t wrote it because of its evolutionary pathways.

      (It could very well be Diaspora is still next on the list, but I’ve decided to continue with Book of the New Sun first. After I finished rereading Shadow of the Torturer I felt I couldn’t really write something meaningful without having reread the next volumes as well. That means less posts on the blog for now, I have about 600 pages to go, I hope to post the review about the full thing in 3 weeks or so.)


  6. Aonghus Fallon

    I wonder if maybe my reading is unconsciously influenced by your website, specifically ‘currently reading’? I’ve started the books of the new sun a couple of times, but never finished them (or at least, not as far as I can remember) and thought I’d break the hex by reading the middle book – ie, ‘The Sword of the Lictor’ which I finished around a fortnight ago (I was also curious to see how dependent story direction was on what had happened in the previous two books).

    Liked by 1 person

    • Did it work for you? Rereading it so far confirms that this really is one book, something that’s much more clear to me than when I read it the first time (and at time I think I read quite a few books between Shadow & Claw and Sword & Citadel).

      Rereading them is a whole different experience, but not necessarily better. So far, I’m much less struck by it as I was the first time.


  7. Aonghus Fallon

    I enjoyed the book a lot. With a few caveats. Some other reviewer (on Goodreads, I think) said he felt as if the same half-dozen characters were following Severian around, popping up at intervals in a variety of different guises* while everybody else he met subsequently got killed, and that these two things didn’t really constitute a plot. I sort of agree!

    * ‘David Copperfield’ does something very similar.

    Liked by 1 person

    • I think I read that review too, or at least one that made a similar point, and I agreed too. The plot for such a – supposedly – complex book is surprisingly thin.


  8. Aonghus Fallon

    Why do you think you found the series underwhelming second time round? And why do you reckon reading the sequence in its entirety was a factor? Just curious.


    • Underwhelming is maybe too harsh, but as it is a reread the sense of wonder is a bit less than my first encounter. To be clear: I still like it, a lot at times, and I know the best is yet to come, so I think it might very well end up being a 5-star read – surely no less than 4 stars. But in my recollections this was a 6-star read, so to say, and that isn’t the case so far;,

      The fact that I want to read it in its entirety is mainly because of this blog, I found that I simply felt it wrong to only review Torturer: because I knew what was still going to come, I felt reviewing on the first book (or the first two books for that matter), wouldn’t really do it justice. Part of that is that I need some of my recollections of the 3rd and 4th book confirmed (or disconfirmed) to really make up my mind about it.

      I also have the feeling that if I would leave time in between books, I would miss out on some of it, miss some of the games Wolfe plays. Those games were less of a factor when I first read it, and now I’m trying to reread it carefully with those in mind (but I’m still not convinced they are worth it, we’ll see).


  9. Aonghus Fallon

    My memory is that I found ‘The Shadow of the Torturer’ to be a book of two halves – it had a strong beginning but the second half was tonally at odds with the first (it reminded me of some Shakespearean comedy, which I found off-putting). Maybe this wouldn’t be so much of an issue if you were reading the five books one after another?

    Liked by 1 person

    • The second part is indeed more baffling, the intro is very strong as you say, sets a certain mood, but then the weirdness takes off and there’s an element of strange humor to it indeed – I’ve noticed it in other books of Wolfe too, I kind of like it, but it’s hard to pinpoint.

      I think the weirdness remains throughout the series, so I think it indeed is less of an issue structurally when experienced as a whole.

      ATM I don’t plan on rereading Urth immediatly after BotNS, as Urth wasn’t planned by Wolfe at first, so I want to review them separately. (Similarly, and related to the complexity in other comment, I don’t like arguments one sometimes reads using stuff from Long Sun or Short Sun to prove New Sun is genius – that’s all after the fact.)


  10. Aonghus Fallon

    As you say ‘supposedly’ – I think a lot of people start reading the books with certain expectations. They’ve been told the sequence is an important work of fantasy with an elaborate subtext etc, etc, only to find the books frustratingly opaque, whereas I think maybe I found ‘The Sword of the Lictor’ enjoyable because I didn’t take it too seriously.

    Liked by 1 person

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