If you have read up on palaeontology, you will likely have encountered the name of Cambridge palaeobiologist Simon Conway Morris. Known initially for his work on the invertebrates of the Burgess Shale, he has since also written on both astrobiology and convergent evolution, which he explored in The Runes of Evolution, his first book with Templeton Press. Always ready for some good-spirited provocation and mischief, he here dissects six supposed myths of evolution, providing a thought-provoking mix of ideas. I found as much to agree as to disagree with.
The first four chapters deal with evolution more widely. I will come right out and say that the first myth, that evolution has no limits, is a bit of a straw man though. I hope that no biologist seriously advocates this: physics has long been recognized as “life’s silent commander“, the concept of fitness landscapes is almost a century old, and I have repeatedly converged on the topic of convergent evolution. Even so, in the process of describing what we know, Conway Morris throws up interesting ideas. Life, it seems, has been complex from a very early stage, readily swapping genes and entering into symbioses; “[…] this genetic turmoil would help to explain why recovering a genealogy of descent has proved so difficult, if not actually impossible” (p. 14). Looking back in time we encounter what Nick Lane has dubbed a “phylogenetic event horizon”, a barrier beyond which we cannot see, much like the cosmological one.
A recurrent and thought-provoking idea in this book is that there is a deeper architecture to evolution. Evolution can be thought of as life endlessly probing the hyperdimensional space of all possible options. Many combinations are theoretically imaginable, but few of these are biologically viable. This is why convergent evolution happens, with life hitting on similar solutions time and again. These concepts also apply to the next myth, that of evolution as a completely random process. A deeper architecture to evolution “may predispose particular chains of causality to be particularly recurrent” (pp. 57–58). In other words, convergent evolution traces the outlines of constraints, raising the intriguing idea that biological hyperspace is “dotted with inevitable destinations” (p. 52). Though one can object that, within these constraints, evolution still acts as a random process. It gravitates towards optimal solutions but does so through trial and error and without foresight.
“Evolution can be thought of as life endlessly probing the hyperdimensional space of all possible options. Many combinations are theoretically imaginable, but few of these are biologically viable. This is why convergent evolution happens […]”
Next up are the myths of mass extinction and missing links. Mass extinctions happen, but rather than radically redirecting evolution, they merely accelerate what was going to happen anyway. Focusing on the end-Permian and end-Cretaceous mass extinctions, Conway Morris observes that groups that came out on top afterwards were “already moving into pole position ahead of the catastrophe” (p. 75). But is this a profound insight or mere circular reasoning? Are you not effectively saying that those species that radiated into newly opened ecological niches were those species that were best situated to radiate into these niches? And we are, of course, dealing with counterfactuals here. Would the dinosaurs eventually have gone extinct and the mammals have come out on top? He argues they would have, but we cannot replay life’s tape to check, making this an interesting but ultimately unverifiable idea. I am not convinced we can confidently claim mass extinctions never radically redirect evolution. What does not help is that, when discussing mammal evolution, his language is somewhat sloppy. Despite his assurances that he does not think that early mammal groups formed a simple scala naturae, “principal lineages tended toward an increasing degree of “mammalness”” (p. 86) and “the thrilling project of “Let’s Make a Mammal” was already well underway by the late Permian” (p. 87). This strikes me as counting the hits and ignoring the misses and then marvelling at the route evolution took to get here. Several recent books discussing early mammal evolution show a younger generation of scientists be more accurate but no less poetic in their metaphors. Missing links are another interesting case, though exactly what the myth is here is never entirely clear. If I understand him correctly, he argues that, rather than a chain of missing links, you observe a swarm of evolutionary experiments all tending in the same direction. Characterised by different mixtures of primitive and derived characters, they are a nightmare to unravel with cladistics and prevent tidy narratives. And echoing the take-home message from Shubin’s Some Assembly Required (that evolutionary innovations never come about during the transitions they are associated with) Conway Morris remarks “it is forgotten that missing links and co-option of existing structures go hand in hand” (p. 113).
Whereas the first four chapters were rather enjoyable, I found much more to disagree with in the next two. Conway Morris provocatively argues that the difference between animal and human minds is not one of degree after all. Discussing mental states, tool use, teaching, language, mathematics, and music, he admits that animals have considerable cognitive chops but that humans really do stand apart. My impression is that he is a tad too sure in denying animals certain cognitive abilities. Work by Frans de Waal and others has shown e.g. empathy and a sense of fairness in apes and Rick McIntyre has observed pretend play in his thousands of hours observing the wolves in Yellowstone National Park, with alpha wolves behaving submissively towards pups to invite them to play. You can probably tell that I am not fond of human exceptionalism, and I will readily quote both Carl Safina and Frans de Waal on why I think we have underestimated animals. However. I cannot deny that Conway Morris raises valid points here. The gap between animals and humans is real and we do not find anything resembling human-level cognitive skills (such as recursive language) in other species. And he is right to point out that where we have tried to train animals, the amount of work required is huge and the results meagre at best. This kind of research does indeed need a rethink, though for me it is all the more reason to push for trying to understand animals on their terms, taking into account their unique sensory window on the world. Safina, for instance, has been justifiably critical of the utility of the mirror-recognition test in ethological research, asking what failure to pass the test really means. At the end of this chapter, Conway Morris asks why we are alone; why, even if there was a significant factor X that triggered the fuse of human cognitive evolution, no other species has followed suit. Perhaps, rather than concluding that human intelligence does not readily evolve, we should conclude that it readily does not evolve. Justin Gregg’s new book If Nietzsche Were a Narwhal offers a suitably amusing riposte, arguing that non-human animals simply do not need it to be successful.
“Conway Morris provocatively argues that the difference between animal and human minds is not one of degree after all. […] I am not fond of human exceptionalism [but] cannot deny that [he] raises valid points here.”
At this point, I feel it is incumbent on me to highlight two points. First, Conway Morris is a man of (Christian) faith and you might wonder whether his talk of a “deeper architecture” to evolution implies there has to be an architect. This book is absolutely not pushing Creationism or Intelligent Design, nor trying to smuggle God in (not even through the backdoor; if you have two hours to spare, I thoroughly recommend Michael Shermer’s recent interview in which he gently grills Conway Morris on this and other topics). And yet. The second point is that Templeton Press is affiliated with the Templeton Foundation, a philanthropic organisation that supports research at the intersection of science and spirituality. The last chapter shows that Conway Morris does have some unorthodox ideas. He considers the search for extraterrestrial intelligence endlessly futile and the Fermi paradox not so much wrong as irrelevant. Why? He has a metaphysical perspective on the nature of reality. Humans, as story-telling animals, have started to literally enter new realities, orthogonal to our own, where we are far from alone. What we call paranormal phenomena and unidentified flying objects are part of those orthogonal realities bleeding over into ours on occasion, he contends. “And these regions have many features that will not please the materialists” (p. 219). But tutting at materialism is a sleight of hand. The reason I, and likely many other scientists, do not engage with these ideas has rather to do with empiricism. If your ideas do not generate testable predictions or are not empirically verifiable (an objection Conway Morris mentions here) we effectively enter the realm of postmodernist nothing-burgers where there is no objective truth and we have no means which to come to a mutually agreeable understanding of how the world works. To me such notions are not vertiginous, as he suggests, they are just not even wrong. Intellectually fun for a while, perhaps, but ultimately idle speculation.
Despite some misgivings, I found From Extraterrestrials to Animal Minds to be a good-humoured and thought-provoking book that both challenged notions I hold dear and provided genuinely interesting ideas. The breadth of research that was put into it is hard to miss, with 167 out of 409 pages providing hundreds of notes per chapter, most referencing multiple papers and responses. I have time for Conway Morris on account of his excellent past work and achievements, while always keeping in mind he is a bit of a provocateur.
Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.
From Extraterrestrials to Animal Minds
Other recommended books mentioned in this review: