This is an interesting account of how evolutionary theory may have developed if Darwin had never written. Peter Bowler is generally a good historian of science, and in many ways this book did not disappoint. It covers familiar ground, such as the acceptance of evolution before Darwin, and the fact that his ideas were not influential in biology until R.A Fisher created the modern synthesis with Mendelian genetics in 1930. However, some rankling inconsistencies detracted from it, which should be addressed.
First, the idea that people believed in constant divine intervention is frequently put forward as though a majority of people, including scientists, believed this in the middle of the 19th century. But the 19th century saw major advances in all branches of science (for instance thermodynamics and electromagnetic theory) and this could not have been the case had people believed this. The model for a scientific theory was Newton’s, the very epitome of the concept of an ordered, law-bound universe. People did not believe then that ‘miraculous’ events happened willy-nilly. Bowler concedes that there was an increasing acceptance of the idea of evolution in the early years of the 19th century, but he does not really convey the fact that it was in fact accepted by most scientists by the middle of the 19th century (although the problem of giving a physical explanation for it still remained).
A somewhat disturbing element is introduced on both p. 38 and p.217. On p.38 it is stated that “..rigidly structured models made good sense to anyone wedded to a vision of nature as a predictable, orderly system….” – in short, wedded to the foundational concept of science. Bowler goes on to say that this made it difficult to accept that the history of life on earth might be essentially irregular and unpredictable – in other words, it would be outside the bounds of science. On p. 217 we find”….there are some people who just can’t bear to think that they are living in a world that is fundamentally disorderly.” No, and for good reasons too. In such a universe, scientific knowledge could not exist. It is the idea that ordered, predictive unbreakable laws exist that makes scientific knowledge possible. If this was not the case, how in fact could anyone tell the difference between what was ‘supernatural’ and what was not? Supernatural events could happen every day and what criteria would be used to distinguish between them? There seems a strange contradiction here, as in some parts of the book it is argued that acceptance of evolution involved acceptance of a law-governed universe as opposed to one where supernatural events occurred (as though anyone actually believed this!), yet in others it is argued that Darwin was hard to understand because it involved a disordered universe. This may seem like nit-picking, but I think there is an important issue of what we understand a scientific theory to be here.
Bowler suggests that people found natural selection hard to understand. He describes it (p.203) as a “concept with which most of his contemporaries could not cope”. In a world where Newton’s theories were the model of a scientific theory, how hard could it have been to cope with? Surely the reason why it played no role in research in the late 19th/early 20th century was the absence of physical explanation.
In discussing how the concept of natural selection might have developed in a world without Darwin there are again contradictions. He points out (p.204) that it does not depend on the notion of nature as a “harsh and relentless force” – it merely depends on a differential in the rate of reproduction. This is in fact how it figures in R.A. Fisher’s synthesis. Yet in other parts of the book, concepts like ‘struggle’ are referred to as though they were real phenomena, physically causal in evolution. Which is it? He does at least acknowledge (pp 244-247) the category errors made by many 19th century thinkers, who seemed to think that biological evolution was a metaphor for social change – or was it the other way round? But metaphor is not physical explanation. And the anthropomorphism frequently present in Darwin’s thinking is not really addressed.
The final chapter involves some strange use of language. On p.273 we read of “critics of progress”. But few people objected to progress (a very Victorian concept) at the time. Besides, evolution, if it is undirected, is not “progressive” – it is not directed towards a final goal. What do we mean by “progress”? How is it defined in biological terms? On page 278 we read: “the idea that death plays a constructive role in progress might have taken longer to become established”. This is written as though it was fact. But what does it even mean in relation to a theory that is not “progressive”? How is “progress” defined in biological terms? What is “constructive”? This appears to be more metaphor and anthropomorphisation. I was also surprised by a reference to the discredited theories of Freud. What do they have to do with the subject matter under discussion, as he was not dealing with phenotypes, that is, physical traits determined wholly by genes, and their interaction with their physical environment, and the only concern of evolutionary theory.
So all in all this is a useful book, but some of the language is unclear, and I was confused at times whether we were dealing with metaphor or explanation.