Book review by Jonathan Clarke, June 2022
From Extraterrestrials to Animal Minds: Six Myths of Evolution
By Simon Conway Morris
Templeton Press: PA, USA, 2022
ISBN: 9781599475288, 272 pages, 1st edition, hardback
Simon Conway Morris is a Cambridge palaeontologist best known professionally for his work on the Burgess Shale and the Cambrian explosion. His less recent works include the books, The Crucible of Creation (1998) about the Burgess Shale fauna, and Life’s Solution: Inevitable Humans in a Lonely Universe (2003) about the role of convergence in organic evolution. Conway Morris is a Christian and was keynote speaker at the ISCAST Conference on Science and Christianity (COSAC) in 2009. More recent works have included several published by Templeton Press, including The Runes of Evolution: How the Universe became Self-Aware (2015).
Conway Morris’s latest work is subtitled Six Myths of Evolution. These are the common myths in the public mind, the media, and even among some scientists: the myths of no evolutionary limits, the essential randomness and directionless-ness of evolution, the essential role of mass extinctions in clearing the ecological decks, prevalence of missing links, animal minds as precursors of human minds, and the supposed abundance of extra-terrestrial intelligence. I will summarise each of these sections in turn.
The “no limits” myth is very popular in the public mind. “Life will find a way” is the mantra whenever the potential limits of life are raised in discussions. But will it? In this chapter Conway Morris shows that there appear to be “Great Walls” in biology; these walls are set by physics, chemistry, and information requirements. Furthermore, while in theory almost everything may be possible, only a few patterns seem to work in the real world, driving to multiple independent reappearances of the same solution. Although majoring on this particular myth, rather confusingly this chapter begins with refuting a myth Conway Morris does not list, the “simple to complex” myth, where he argues that there are relatively short-lived episodes of great biological innovation leading to great complexity, followed by streamlining and simplification. Conway Morris describes many examples of this process, including the rise of amphibians, birds, and mammals. This might have been worth a chapter of its own.
The randomness myth was perhaps expressed best in the essays of the late great Stephen Gould. Evolution was a random process, lacking constraints, beyond the bounds of minimum complexity. There was no direction to evolutionary processes. However, as Conway Morris has already documented extensively in earlier works such as Life’s Solution (2005), similar features appear independently again and again throughout evolutionary history to solve the same problems in different taxa. This phenomenon occurs at all scales, from the convergence in body shape in sharks, dolphins, tuna, ichthyosaurs, and mosasaurs, down to the fundamental molecules of life such as oxygen-transporting compounds, optical sensors, and chlorophyll. Again, while in theory almost everything may be possible, the reality that only a few patterns actually seem to work provides a major constraint on evolutionary patterns and a strong driver for specific solutions to biological requirements.
Mass extinctions are those great events in the history of life where large numbers of taxa, often at high levels, disappear over a short period of time. The two largest, and the two that have most grabbed the popular imagination, are the Permo-Triassic extinction, where perhaps 90% of species died out and the Cretaceous-Tertiary extinction, which saw 75% of species become extinct (percentages vary). The cause of the Permo-Triassic extinction is not yet understood but the Cretaceous-Tertiary event was largely because of an asteroid impact in what is now Yucatan. Conventional wisdom argues that mass extinctions clear the decks, wiping out old groups and allowing new or suppressed groups to flourish. Had the asteroid not struck Yucatan, the argument goes, mammals might have remade little scurrying things and the world would still be dominated by dinosaurs. However, Conway Morris argues that the picture is much more complex. Many taxa that disappeared during the extinction events were in fact already being replaced, such as extensive replacement of conifers by flowering plants in the Cretaceous. Mammals would probably have replaced dinosaurs in many niches anyway, because of more sophisticated metabolisms, much as birds were replacing pterosaurs in the Cretaceous in many niches. So rather than entirely resetting the evolutionary landscape, mass extinctions had more the effect of speeding up trends already in place.
The discovery of so-called “missing links” are beloved in the popular media, the discovery of such a possible link supposedly fills forever a gap in the evolutionary record (for example the transition from fish to amphibians or dinosaurs to birds) or proves once and for all that Darwin was right. Conversely, they are loved by anti-evolutionists: their supposed absence proves that there are gaps that can never be filled; ergo Darwin was wrong. Conway Morris’s chapter on this myth shows that, as always, the reality is very different, on at least two counts. The first is that rather than a simple transition from sarcopterygian fish to a Ichthyostega-like amphibian which can be neatly plugged by a single fossil like Tiktaalik, what we see is a tangled thicket of forms, often with mixed primitive and advanced characteristics, where the exact line of descent is difficult if not impossible to demonstrate, even though the general relationship between sarcopterygians and amphibians is clear from palaeontology and genetics.
When I was an undergraduate biology student, animals were little more than automata, whose behaviour was the result of simple conditioning. Subsequently there have been many claims in popular science media of advanced cognition, cultural development, proto-linguistic development, and other indications of sophisticated animal minds. Conway Morris provides much-needed caution on these claims, providing counter examples and caveats that are not likely to make it into the popular media. While not the automata of my student days, animal minds remain both quantitively and qualitatively different from human minds, according to Conway Morris. However, this chapter is weaker than the preceding ones. If humans evolved from earlier primates, as Conway Morris argues, how then did human minds appear? Are they an emergent property once a particular threshold was crossed, or was something else involved? More explanation would have been helpful.
Even weaker is the chapter on the extra-terrestrial myth. Conway Morris is correct in pointing out that while the idea of a universe teeming with sapient beings, if not entire technological civilisations, is popular, where then is everybody? Not only is there the apparent lack of evidence of technology in the observed universe, but there is also the absence of any traces of alien visitation in the billions of years of geologic time. The “great silence” Conway Morris argues, as do some others, suggests that we are alone in the universe. Life may (or may not) be common elsewhere; mind probably not. However, the reality is we simply do not know, and I suspect that Conway Morris here writes with greater confidence than is perhaps justified. The last part of this chapter becomes very odd indeed, with Conway Morris wandering into literature on paranormal and similar events. It is not clear where, if anywhere, he intends to go with this, or its relevance to the rest of the subject matter.
To conclude, this is a readable, provocative, stimulating and, for the most part, well-founded book showing how these evolutionary myths are often misleading, if not actually unhelpful. I would have liked the book to have addressed two other myths, the first that of the simple to complex. Conway Morris touched on this in Chapter 1, but a separate chapter would have been most helpful. As an astrobiologist, a chapter on the beginnings of life and the various narratives attached to that, would have been interesting. As mentioned, the last two chapters are rather weak, and the book ends on quite a strange note. Despite these caveats, I recommend it strongly to anyone interested in palaeontology, organic evolution, and to a lesser degree, the nature of mind and human evolution.
Overall, this is a useful book exploring some of the larger questions in the patterns of biological evolution by a leading thinker in the field. It is well referenced and provides much to ponder.
 The Crucible of Creation: The Burgess Shale and the Rise of Animals (Oxford University Press, 1998).
 Life’s Solution: Inevitable Humans in a Lonely Universe (Cambridge University Press, 2003).
 The Runes of Evolution: How the Universe became Self-Aware (Templeton Press, 2015).