by Mark B. Adams, Professor emeritus, University of Pennsylvania
Editor’s note: The act of reviving and polishing the text of a thirty-year old article led this author on a trip down memory lane. The HSS Newsletter is delighted that he shared his memories with us, thereby offering a peek into how history is made and done.
Remembrance and reflection, how allied!
What thin partitions Sense from Thought divide!
—Alexander Pope, Essay on Man
Pope’s words have a special resonance for me. I spent much of 2020 updating for publication what is perhaps the most important and unusual article I have ever written: “Little Evolution, BIG Evolution: Rethinking the History of Darwinism, Population Genetics, and the ‘Synthesis.’” It brought back many memories.
Four things make the article unusual. First, the text had been collecting dust in my drawer for 30 years. Second, it was my only publication that drew upon all the varied training and research I have undertaken in the course of my professional life. Third, the paper argues that the traditional story of Darwinism through the “synthesis” that I (and many others) have taught for more than 40 years (and to which I contributed) was… wrong. Finally, it is the only paper of mine that discusses in detail the thinking and writing of legendary scientific figures, now mostly dead, whom I actually had met, known, and worked with.
In a sense, the paper originated with a week-long interview of the geneticist and evolutionary biologist Theodosius Dobzhansky (“Doby”) conducted in Mather Camp, Yosemite during his field trip there in 1973, two years before his death. This interview itself was the outcome of the fact that my mentor, the evolutionary biologist Ernst Mayr, had invited me to the two conferences on the “evolutionary synthesis,” which became the raw material for Mayr and Will Provine’s book on the subject, to which I contributed two articles on Russian developments. It was at one of those meetings that I first met Dobzhansky. I asked him if there was any way I could interview him at length, especially about his early career and all his firsthand experiences in Russia during the 1920s. He graciously suggested that if I could come to California, I could join him for a week on one of his field trips. I took him up on his offer.
Each day during that week at Mather Camp, after he had finished his field work, I would join Doby on his porch, chatting and recording our conversations, one day in English and the next in Russian. He spoke a lot about his Leningrad mentor, Iurii Philiptschenko, for whom he had an almost worshipful respect and admiration, pronouncing him as the finest geneticist, biometrician, breeder, and evolutionary theorist in pre-revolutionary Russia and throughout the 1920s. It was from Philiptschenko that Doby adopted the terms “micro-evolution, macro-evolution” that his own 1937 book, Genetics and the Origin of Species, made standard. He also noted that his mentor had created those neologisms in 1927 to distinguish varieties and species from genera and higher taxa, to make the case that, however useful in understanding the former, genetics could not illuminate the latter, namely evolution. Yet, I knew that a decade later, now at Columbia, Dobzhansky deployed his mentor’s neologisms to argue just the opposite!
Puzzled, I asked him how he accounted for that difference. I was expecting a technical answer—perhaps it had been the influence of the Morgan School, his work with ladybird-beetles, or some experience he had had. Instead, he shrugged, and said, almost indifferently, “He bet on the wrong horse.” Doby, I should mention, was an inveterate horseback rider, and was riding in Central Park when he was injured; he convalesced for weeks in hospital, where, at the urging of L.C. Dunn, he used the time to draft his classic 1937 book from memory, only adding the bibliography when he could return to his office.
“Bet”? “On the wrong horse?” I was startled, having never in my innocence thought of science as a “horse race” or a “betting” matter. That comment changed my perception. Here was a scientist who had not been certain of his own approach, but rather someone who realized it might have gone either way, and chose the option that, if it turned out to be right, would both justify and energize his newly coined specialty, “population genetics.” At the time, I was collecting information on the Russian eugenics movement, but I never forgot Doby’s remark, and stored it away.
In subsequent years, I began to explore population genetics and the evolutionary synthesis in greater detail, gradually losing patience with triumphalist accounts. Aside from giving an annual lecture course on the history of evolutionary thought at the University of Pennsylvania, where I continued to teach the “traditional” view, I broadened and deepened my understanding while preparing for various invited talks at universities, meetings, and other settings throughout Europe and North America. My first published version of these ideas was actually in French, but fearing that many of my colleagues could not (or would not) read French—and engrossed in the subject—I set about writing a more extended English version of my thoughts. It was then that certain memories came to mind, which ultimately led to my “epiphany.”
I remembered Bill Coleman’s paper at the Mayr meeting when he had asked, “What exactly is the evolutionary synthesis, and what did it synthesize?” At the time, I thought he was uninformed; on reflection, I thought it an excellent question. I also remembered how “Darwinism” meant such different things to different thinkers. Lysenko’s “Creative Darwinism,” for example, was almost the complete opposite of the Darwinism of the “evolutionary synthesis.” I remembered Bentley Glass’s review of the Mayr/Provine volume, which asked: Could it be the case that Creationism had absolutely no impact on the evolutionary synthesis? (Another good question). Haldane’s classic book had declared, “Many would refuse to dignify the changes which man has effected in the dog as evolution.” Just five years later Doby had redefined evolution as “a change in the genetic composition of populations,” which surely included dog breeding. Weren’t those two claims by founding population geneticists contradictory? I remembered conversations with my good friend Steve Gould about his “punctuated equilibrium” theory, which Mayr had so opposed (“evolution by jerks,” he once called it.). A final memory brought my meditations into focus: Doby’s comment that Philiptschenko, his revered mentor, had “bet on the wrong horse” about the “micro-/macroevolution” issue. When was that ever settled, I wondered? Something didn’t feel right.
So I set about digging into all the classic texts that I had been collecting over the years. I knew perfectly well what they were supposed to have said… but what did they actually say, in print? I was gobsmacked by what I found: it had never been settled! Had Philiptschenko bet on the right horse, after all? It was only then that I finally came to realize: the “micro/macro” issue had always been, throughout, the core problem of Darwinian evolution! That discovery led to my first draft of the English version of the paper. As I shared my findings with colleagues, I was strongly encouraged to prepare it for publication in Isis by its editor, who suggested that I extend and revise it in certain ways. Despite a heavy workload, I eventually came up with an almost final version, but Isis had changed management meanwhile. So the article remained in the drawer, while I returned to demanding teaching and administrative duties, and published on other subjects.
I did retain a digital version of the article, however, and when correspondents sent me questions about Doby, Mayr, G. G. Simpson, and other scientists whom I had known, I would send them a copy of my paper. Over the years, various colleagues, including biologists, historians, and philosophers, encouraged me to find some way to make it publicly available, so they could cite it. After several such requests, I received an inquiry from Richard Delisle (whom, unfortunately, I have never met), and sent him a copy of the paper. Unbeknownst to me, he was (and is) the editor of a Springer series on evolutionary biology, and he immediately suggested publishing it in his forthcoming volume on “Natural Selection.” We came to an understanding, I updated it here and there, and benefited from the feedback and criticism from him and other colleagues, new and longstanding. Only the section on Julian Huxley was newly added, at Delisle’s prompting. The standard references are from 1990; the footnotes provide new, 2020, relevant information, perspectives, comments, reflections, memories, and personal experiences.
I am neither a biologist nor a philosopher, but an historian. At one point, with the passage of time, I thought that by now, surely, many would have already realized the failings of the traditional view, so there was no need for me to publish my ideas. But as I learned from co-teaching a course on evolution with a biologist a few years ago, such was not the case: the “traditional” narrative still holds sway. The biologist’s “evolution” was entirely “micro”—population genetics, equations, fitnesses, and how intraspecific populations “evolve” when their gene frequencies change—and no mention whatsoever of the “macro”: the origin of higher taxa, fossils, extinctions, or the unfolding history of life and nature on our planet. I am not so foolish as to think that my updated 1990 paper’s publication will overthrow the prevailing narrative, but I am very pleased to finally be able to make it available to interested colleagues and a broader readership.