For Darwin’s birthday, I thought I’d mention two books about Darwin, both by the noted Darwin scholar John van Wyhe, whom Jerry and I have both had the pleasure of meeting, and who we’ve had occasion to mention here on WEIT a number of times. As anyone with more than a passing interest in Darwin should know, John is the editor of the indispensable Darwin Online.
The first is Darwin: The Man, His Great Voyage, and His Theory of Evolution (Andre Deutsch, London, 2018). Although I hadn’t planned it that way, very fittingly I finished reading it this morning. This is a reissue of a book first published in 2008 in anticipation of the Darwin bicentennial. The first issue was published in the US and the UK with different subtitles, and slightly later (2009) in the US.
I can highly recommend this as a very well-illustrated capsule summary of Darwin’s life. It begins with one of the best summaries of the state of knowledge and inquiry into natural history in the early 19th century I’ve ever read, then takes up Darwin’s life from birth, to university, to the four corners of the Earth in the Beagle, then to his return to England. Succeeding sections (there are no numbered chapters) are mostly structured around Darwin’s major works, tracing his life and contributions through a chronological sequence of those works.
The text covers at most half of the pages of this 160 page book, the rest being given over to illustrations. Almost all are contemporary, either illustrations from scientific papers and monographs, or of people and places in Darwin’s life. There are also quite a few reproductions of pages from Darwin’s published works and manuscripts. (Pages 120-123, a reproduction of several pages from the Darwin-Wallace Linnean Society paper of 1858, is labeled, incorrectly, as an extract from one of Darwin’s unpublished MS from 1857.) The illustrations are a great plus. In the original issue of 2008, the selection of illustrations was somewhat different (there were more of them), and they were larger, some being fold out; in the current issue the size may be a bit of a problem in seeing detail in some of them.
My own copy is the UK issue of 2018. A US reissue has a 2022 copyright date, but the UK one of 2018 is available in the US. (The larger format issue of 2008 [2009 in the US] can also still be found.) To learn all about Darwin’s life, read Janet Browne’s 2-volumemasterpiece. But until you do, read this book, and have it alongside for the illustrations when you read Browne.
Unlike the previous book, which is a great entry point for the tyro, this book is for the more serious student of Darwin. The Companion is an encyclopedic collection of virtually everything known to be connected to Darwin the man. The new edition is 50% again as large as the first, and has added several dozen illustrations. This is not really a book to be read, but rather consulted or browsed (in the nutritive sense); Darwin completists will need a copy. As Janet Browne wrote in her blurb for the new edition, “There is more here than even Darwin would have known about himself.”
As Jerry noted at the time, this past Wednesday was Darwin’s Birthday. My evolutionary biology class met the previous day, Tuesday, and the first slide I showed for the day was the following.
The “click here” in the middle of the slide led to a performance of the Beatles’ song “Birthday”. (For copyright reasons, the video features the Beatles, but the sound is Paul alone in a post-Beatles performance.)
On Darwin Day itself, I watched Creation, a 2009 biopic about Darwin starring Paul Bettany as Charles and Jennifer Connelly as Emma. I did not see it at the time of its release, and it had some difficulty finding a U.S. distributor, ostensibly because Darwin and evolution were too controversial for the American public.
Jerry gathered a few reviews at the time, which were not terribly enthusiastic. I took a look at those reviews, one in the N.Y. Times by A.O. Scott, my favorite film critic, and one by Ryan Jay, another favorite critic. Both were also lukewarm on the film, Jay giving it his middling score of “Rent It”, with Scott being a bit more harsh:
It aims for a liberal-minded balance, at least on the thematic level. But at the same time the film traffics in the pseudo-psychological mumbo-jumbo that is the standard folk religion of the film biography, and undermines its interest in reason by dabbling in emotive pop occultism. Recoiling from the possibility that ideas themselves might impart tension and interest to this tale, Mr. Amiel [the director] and Mr. Collee [the writer] induce a kind of literary brain fever and reduce Darwin’s work to a symptom of his mental and emotional anguish.
I did not look at the reviews before watching the film, so the following comments are not “pre-influenced”. A
ll in all, I was disappointed. The production values are high, and some filming was even done at Down House. The level of production design accuracy was fairly high (e.g., the washroom with curtain in Darwin’s study). Parts of the dialogue I recognized as being taken from Emma’s and, especially, Charles’ letters. Bettany, as made up, does a fair Darwin impersonation, and I was charmed by Benedict Cumberbatch’s unexpected turn as Hooker. (Cumberbatch was largely unknown, at least to American audiences, at the time, and is buried in the credits.) But Connelly is given almost nothing worthwhile to do, wasting her talents; and Huxley (played by Toby Jones) is written as crankily aggressive, rather than as the erudite explicator he seems from his public writings.
And the plot seems quite muddled. The film centers on Darwin’s relationships with Emma and, even more so, on their daughter Annie, who died in 1851. But most of the action takes place several years later, with frequent flashbacks (some to the Beagle voyage), yet Annie is everywhere (except the Beagle). This may be a case of knowing a little being dangerous, as I kept trying to fit the various scenes into a coherent timeline, and only later realized that Annie is a ghost, or better, a symptom of Darwin’s hallucinations, in many, though not all, of the scenes. I don’t know if a naive viewer would be more or less confused than me by this.
Were I someone not versed in the history of evolutionary biology, I would thus give it a mixed review. But knowing some of the actual history, I found some of the themes of the film suffered from being, at best, misplaced in their emphases. The film shows Darwin as losing (most of) his Christian faith as the result of wrenching inner turmoil, leading to open conflict with Emma, with the death of Annie pushing him towards the edge of madness and final loss of faith. Darwin’s well-known ill health is portrayed as essentially psychosomatic, the result of guilt over Annie’s death and his loss of faith. And, his nagging internal torments delayed his work for many years. While there is a grain of truth in each of these elements, the resulting picture is distorted. Darwin did mourn the death of Annie; he did love Emma dearly, and fretted over their differences with regard to faith (see especially this); he knew that consanguineous marriages could lead to “weakness” in children; and he was ill. But he wasn’t nearly mad; his faith more nearly slipped away; he probably didn’t delay terribly long; and the child whose illness was vexing him at the time was not Annie (long dead), but little Charles (who died shortly after Darwin received Wallace’s letter from Ternate).
I searched for, and found two contemporaneous reviews from a more scientific/historical (as opposed to film criticism) perspective. The first was a review by Janet Browne, Darwin’s most authoritative biographer, and professor of the history of science at Harvard. As do the film critics, she takes a lukewarm view
The movie Creation gives . . . a fictionalized perspective. . . Once one gets over the mismatch between the known historical record and the sentimental version of Victorian family life that is presented here, the film has some rather good sections. . . . [Darwin’s] love for his nine-year-old daughter Anne excessively dominates the plot. There are some delightful scenes, mostly in flashback again, followed by some stupid ones in which Darwin becomes so deranged by her death that he has nightmares (overly tinged with Henry Fuseli) and continuously hallucinates her presence. About ninety minutes into the film, the storyline goes haywire with Darwin vomiting, weeping, and hallucinating. The death of this daughter is presented as the emotional fulcrum of the film, bringing the religious differences of her parents to the fore and serving as a foil for drawing out Darwin’s doubts about publishing. Perhaps.
The other review was by James Williams, senior lecturer in science education at Sussex. His review is scathing. He notes the confusing chronology, details a number of errors and lapses, and laments that the actual events would have made for a better film. Some excerpts.
It promised so much, yet delivered a turkey! . . .
Granted, the film did give some excellent and accurate portrayals of events, but why deliver them out of sequence and why leave out some important details, yet include others? . . .
The film is set in 1858-59, seven years after Annie’s tragic death. Yet the filmgoer is left firmly with the impression that she is alive in 1858 and dies sometime in 1858/9. . . .
At least Alfred Russel Wallace (my personal hero) did get a mention – but only just. It was the receipt of Wallace’s letter by Darwin that prompted Charles Lyell and Joseph Hooker to urge Darwin to write Origin, not a visit by Huxley.
Darwin was distraught by the letter he received from Wallace (accurate in the film), but what put pressure on him was not Annie’s health (she was already dead at this point remember) but the health of his newborn son Charles – who did actually die during the period of his receipt of Wallace’s letter – and the fact that children in the village were sick and dying. Just how Emma could be pregnant with Charles junior, at the same time as worrying about Annie’s health, defies biological understanding.
The film makers were determined to make Annie the focus of Darwin’s angst during the writing of ‘Origin’ and deemed this to be the dramatic ‘device’. When you look at the REAL story of how Darwin was almost forestalled and what was happening in his life during June/July of 1858 and through to the publication of ‘Origin’ in 1859 – there was drama enough without having to destroy historical accuracy.
The film is based (loosely, as Williams insists) on Annie’s Box, by Darwin’s great-great grandson, Randal Keynes. I recalled a paper by John van Wyhe debunking the hypothesis that Annie’s death ended Darwin’s faith. (We have had a number of occasions here at WEIT to comment favorably on van Wyhe’s work, including his editing of Darwin Online, and Jerry was able to meet him on a visit to Singapore, while I did the same when I invited him to speak as part of our Darwin bicentennial celebrations.) The paper was from 2012; Van Wyhe and his coauthor, Mark Pallen, wrote
That Annie’s death caused great distress to her parents and family is beyond dispute. A week after her death Darwin penned a tender memoir of Annie, which was first published (in part) by his son, Francis, in The life and letters of Charles Darwin (1887) . . . Darwin closed the memoir with a cry from the heart: ‘We have lost the joy of the Household, and the solace of our old age:—she must have known how we loved her; oh that she could now know how deeply, how tenderly wedo still and shall ever love her dear joyous face. Blessings on her.’ However, it must be stressed that nowhere in the millions of written words by Darwin that survive did he ever indicate, directly or indirectly, that Annie’s death had anything to do with his loss of faith. Of course it would be naïve to restrict the evidence only to explicit statements. But first we must acknowledge that there are none. Furthermore, as we shall see, the balance of all surviving evidence that bears on his loss of faith suggests there was no connection with Annie at all. . . .
The suggestion of a sudden death knell for Darwin’s religious belief built on strong emotion stands in stark contrast to his consistent accounts of his loss of faith, which followed from an assessment of the evidence for Christianity and which took place at a‘rate:::so slow that I felt no distress’ (Barlow, 1958, p. 87). Yet Annie’s death was the most distressing event in Darwin’s life. No explanation for this dramatic contradiction has ever been provided. The time has come to bury the Annie hypothesis.
So, in 2009, it was perhaps defensible, or at least popular, to suppose the truth of the so-called “Annie hypothesis”, but van Wyhe and Pallen seem to have laid it to rest.
Another element of the film, though not quite as prominent, is Darwin’s “delay”. Van Wyhe has also addressed this in his paper “Mind the Gap”
In this essay it is argued that not only is there no evidence that Darwin avoided publishing his theory for many years, but the evidence is overwhelmingly against that interpretation. By re-examining the historical evidence, without presuming that Darwin avoided publication, it can be shown that there is no reason to introduce such a hypothesis in the first place. If we come to the evidence already believing that Darwin put it off, then vague and ambiguous passages will seem consistent with such a view. . . .
A fresh analysis of Darwin’s manuscripts, letters, publications and the writings of those who knew him intimately shows the story to be quite different from one of a lifetime of avoiding publication. It will be demonstrated that Darwin’s delay is a historiographical theme of quite recent date and unknown not only to Darwin and his contemporaries but also to generations of writers after them. Furthermore, this theme is not the product of the greater knowledge of Darwin produced by modern historical scholarship since the 1960s. Modern writers inherited Darwin’s delay from earlier writers who did not have access to the full manuscript corpus.
In fact, Darwin hardly veered from his original plans for working out and publishing his species theory in due course.
If you are a Darwin completist, you’ll want to see the film, but otherwise you can skip it. Its emphases seems wrong, perhaps to the point of no return; but I did enjoy some parts, and the segment conjoining Annie’s death, and the death of a young orangutan at the London Zoo, moved me near to tears. As Janet Browne concluded, “In my view the juvenile orangutan was outstanding.”
Browne, J. 1995. Charles Darwin: a Biography. Volume 1. Voyaging. Princeton University Press, Princeton, New Jersey.
Browne, J. 2002. Charles Darwin: a Biography. Volume 2. The Power of Place. Knopf, New York.
Browne, J. 2010. [Review of ] Darwin’s Darkest Hour [and] Creation. Bulletin of the History of Medicine 84:671-674. gated
Wyhe, J. van. 2007. Mind the gap: did Darwin avoid publishing his theory for many years? Notes and Records of the Royal Society 61:177-205. Darwin Online
Wyhe, J. van, and M.J. Pallen. 2012. The ‘Annie hypothesis’: Did the death of his daughter cause Darwin to ‘give up Christianity’? Centaurus 54:105-123. pdf
Jerry’s back from his southern sojourn now, and may have made some posts from Chicago by the time you see this, but as he settles back in I thought it would be good to recall the lessons that another famous evolutionary biologist learned in the Falklands. Although we all associate Darwin with the Galapagos, his visit to the Falklands (also during the Beagle voyage) supplied an important bit of evidence in his thinking about islands, and the phenomena of island life were crucially important components in his argument for evolution.
Darwin was a bit perplexed by the Falklands. In many ways they seemed like oceanic islands—islands never connected to a continent, which had received their biota from across the seas by what Darwin called “occasional means of transport”. There was only a single native species of land mammal on the Falklands: the Falkland Islands fox, which was clearly related to South American foxes. (South America has a modest radiation of canids, which are variously called dogs, foxes, or wolves in English). The mammal fauna was thus depauperate (few species); disharmonious (lacking major ecological or taxonomic groups); and showed affinity to the fauna of the nearest continent (the effect of distance)—all of these are characteristics of oceanic islands.
How the fox got to the Falklands is an issue that concerned Darwin, but that’s not what I think was most important. (The issue of how they arrived, and when, was largely solved a few years ago, and we discussed it here at WEIT: the short answer is that lowered sea levels during the last glacial maximum greatly shortened the distance to the continent, and the fox came across, perhaps floating on ice floes, as Arctic foxes do.) The problems that the Falklands helped Darwin with most was why oceanic faunas were depauperate and disharmonious. Darwin’s evolutionary hypothesis was that it was difficulties of dispersal that led to oceanic faunas being apparently “undercreated”.
But there was an obvious alternative explanation: the ecological conditions on the islands are unsuitable for a species-rich, harmonious, fauna, despite seemingly appropriate physical environmental conditions. The oceanic faunas were not “undercreated”, but inhabited by the ecologically appropriate species.
These competing explanations are easily tested by introducing exotic species to the island, and seeing how they fare. If they become established, then the cause of their absence is a failure of dispersal, not a failure of environmental suitability. This is where the Falklands helped Darwin, I think. The Galapagos in the 1830s were still nearly pristine, but the Falklands showed him the fauna of an island with little direct habitat disturbance, and a small human population. But the people who had settled the Falklands brought their animals with them. At the time of his visit, Darwin recorded wild populations of cattle, horses, pigs, rabbits, rats, and mice, with cats, dogs and sheep coming later. The Falklands were thus quite capable of supporting a diverse and harmonious mammalian fauna; the mammals just needed help getting there!
So we can see that exotic mammals of all sorts do quite well in the Falklands, and that Darwin’s evolutionary hypothesis is thus supported. Although I’ve read up on the Falklands, Jerry’s visit there is the first by anyone I know, and he has provided firsthand reports on, and pictures of, the exotic mammals. So here again is a bovine, the Belted Galloway:
and a dog:Jerry tells me that sheep are “all over the place there!”, but, unfortunately, he didn’t get any pix of them. So here’s one that I found on the Internet, by Jeremy Richards, who has also sagely captioned it:
Note from Jerry: Greg plans to run a mini-MOOC here, so if you want some education in evolution, do the readings and answer the questions (to yourself). This is the first installment.
by Greg Mayer
This semester I’m teaching BIOS 314 Evolutionary Biology, an upper level undergraduate course. The students are all or mostly biological sciences majors, and general genetics and biostatistics are prerequisites for taking the course. As a textbook, I use Evolution, by Doug Futuyma and Mark Kirkpatrick, published by Sinauer Associates of Sunderland, Mass., which last year became an imprint of Oxford University Press. This is the 4th edition of the current iteration of this text, which also had 3 editions under an earlier iteration with the title Evolutionary Biology. Doug was my undergraduate evolution teacher, and I took the class with him while he was writing the first edition of Evolutionary Biology.
I hope to say more about the textbook later, but I also have the students read a series of what I regard to be classic papers or extracts– one each week–and these are what I want to share with WEIT readers. Each reading is accompanied by a brief biography and illustration of the author, and a small number of study questions, designed to guide the student in understanding the reading. I sometimes assign these questions as homework essays, or include them on exams. The first week’s reading each time I’ve taught the course this way has been an extract from the Origin. I will, when possible, provide links to the readings. For this Darwin reading, you can use John van Wyhe‘s superb Darwin Online. I’ll be posting a reading every few days. If you want to read along, it will be like taking a guided readings course in evolutionary biology.
Charles Darwin (1809-1882), after studying briefly at Edinburgh to be a physician, went to Cambridge to prepare for the Anglican priesthood. While there, his interest in natural history attracted the attention of his professors, which led to him being invited aboard H.M.S. Beagle as a supernumerary naturalist for that survey vessel’s global circumnavigation (1831-1836). By the time he returned he was already a recognized geologist, and, leaving the ministry behind, he soon established himself as a rising star in all departments of natural history. After study of his Beagle collections convinced him that species were not immutable, he discovered natural selection as a means of modification. Spurred by the later but independent discovery of natural selection by A. R. Wallace, he published his views and evidence in On the Origin of Species in 1859. Within a few years, the whole of the scientific community accepted descent with modification as the key process underlying the phenomena of the organic world, though natural selection as the chief means of modification was not accepted during Darwin’s lifetime. Among his many other works are Zoology of the Beagle (1838-1843, edited by Darwin), Voyage of the Beagle (2nd ed., 1845), Variation Under Domestication (1868) and The Descent of Man (1871). All of Darwin’s published works are available at John van Wyhe’s Darwin Online, http://darwin-online.org.uk/. He is buried in Westminster Abbey, not far from Sir Isaac Newton. The best biography is Janet Browne’s Charles Darwin (vol. 1, 1995; vol. 2, 2002).
1. Why is the concept of homology crucial for even being able to talk about organic structure? How are homologous organs recognized? What is Darwin’s explanation for homology?
2. How does Darwin’s account of serial homology (the resemblance of parts within an organism, for example, the forelimbs to the hindlimbs, or of a cervical vertebra to a thoracic vertebra) depend on the repetition of parts or segmentation?
3. What is the “law of embryonic resemblance”? How do these resemblance relate to the organisms’ conditions of existence? How does this relation depend on whether the embryo is active and provides for itself?
4. When during development does Darwin suppose most species differentiating characters to become evident? How does this relate to when he supposes the characters to affect the survival and reproduction of their bearers?
Darwin lived in the country, and had many animals– for companionship, work, and research. For companions, his chief pets were d*gs (my favorite of Darwin’s d*gs was Bob), but he also had a tortoise that he brought home from James (Santiago) Island in the Galapagos. It has been claimed (most notably by the late Steve Irwin of Crocodile Hunter fame) that this tortoise later made its way to Australia, where it was named Harriet and lived to be about 175 years old. I always thought this story had dubious links in its chain of evidence, and Paul Chambers, in A Sheltered Life: The Unexpected History of the Giant Tortoise, after an exhausting examination, considered the story untrue.
Unbeknownst to me, four years ago Aaron Bauer and Colin McCarthy revealed the true fate of Darwin’s tortoise: it’s in the Natural History Museum in London, which is pretty much where you would have expected it to wind up. Henry Nicholls in the Guardian, in a Darwin Day tortoise piece, reminds us all of this fact, telling some of the details of the specimen’s history and rediscovery.
McCarthy, at the time the herpetology collection manager, found it in a store room in March of 2009, while preparing a list of Darwin specimens in the collection. Its original registration number shows it was catalogued on August 13, 1837, so it lived only a relatively short while after getting to England.
I am not at all surprised that it turned up at the Natural History Museum, nor that it was lost track of. The big, older, museums have large collections, and earlier curation policies were not up to today’s standards. There’s an old story, perhaps apocryphal, that a British paleontologist once submitted a grant application to fund an expedition to the basement of the museum!
According to Nicholls, you get to see the tortoise as part of the “Spirit Collection Tour” at the museum. “Spirit” refers not to the departed specimens’ souls, but to their method of preservation: in spirits. (Such specimens are called “alcoholics”, which causes some initial confusion when referring to them in front of a non-museum audience).
In honor of Wallace Year, Greg Mayer is doing a series of posts on The Man Who Came Second. This essay gives Greg’s take on the rivalry between Darwin and Wallace about the discovery of natural selection, and how it was resolved.
Darwin and Wallace at Burlington House
by Greg Mayer
The theory of evolution by natural selection, co-discovered by Charles Darwin and Alfred Russel Wallace, was announced to the world at a meeting of the Linnean Society held at Burlington House in Piccadilly on July 1,1858. Neither Darwin, who was at Down House in Kent, nor Wallace, who was collecting in the Malay Archipelago, were present.
Seven weeks later, and 155 years ago today, the theory was published in the Society’s Journal—on 20 August 1858 (Darwin and Wallace, 1858). Darwin provided a much fuller account of the theory the following year in On the Origin of Species (Darwin, 1859), and went on to write several more books, each of which may be considered an elaboration or application of the theory. Wallace remained in the East Indies until 1862. After returning to England, he too wrote several books, the best known being his account of his East Indian expedition (Wallace, 1869), his applications of evolutionary reasoning to zoogeography (Wallace, 1876, 1880), and a general exposition of evolution (Wallace, 1889).
Although the theory at its announcement was attributed to both men, it has come to be associated primarily with Darwin. Indeed, even Wallace entitled one of his most important books Darwinism (1889), and always considered Darwin to be at least primus inter pares. Some, however, have thought that Darwin’s lion’s share of the credit is undeserved, and that Wallace has been wronged, both by Darwin and by history (Brackman, 1980; Brooks,1983; Quammen, 1996; Davies, 2008).
The accusations against Darwin are that he ‘stole’ one or more ideas from Wallace, and that the circumstances of the reading and publication of the Linnean Society papers were somehow unethical. Although ostensibly arguing on Wallace’s behalf, these authors must dismiss Wallace’s own accounts (e.g. 1870, 1889, 1905, 1908) of the contributions made by Darwin and himself, and paint Wallace as a victim. But, as his biographer Raby (2001:291) says, “Wallace was not a victim, and he did not see himself as a victim”; to do so “diminishes both Darwin and Wallace.”
I argue here, in agreement with Raby and others, that these accusations are baseless, and that a fair reading of the historical evidence shows that the high and friendly regard (Kottler, 1985; Raby, 2001; Shermer, 2002) in which the two men held each other throughout their lives was well deserved on both their parts.
It is helpful to begin by recounting some of the history of both Darwin and Wallace, for it sets the context for later events. The following account draws on standard historical works, especially Kottler (1985), Browne (1995), Ruse (1999), Raby (2001), Shermer (2002), Bowler (2003) and Young (2007).
When Darwin returned from the Beagle voyage in late 1836, he was not yet an evolutionist, but by mid-1837, when he began his first notebook on transmutation, he was. By late 1838, after considering a number of possibilities, he hit upon natural selection as the mechanism of transmutation, and for the rest of his life he was to consider this the chief (though not exclusive) mechanism of evolutionary change. In 1842 he wrote a 35-page outline of his views which has come to be known as the Sketch. Darwin elaborated this into a 230-page Essay in 1844 (both were eventually published in 1909). At this time he first revealed his theory of natural selection, showing the Essay to the botanist J.D. Hooker. The theory in the Sketch and the Essay is the same as that given in the Origin. As Wallace had not yet published on—or even thought very much about—the subject, Wallace had no influence on Darwin’s formulation of natural selection.
Wallace’s evolutionary history begins a few years after Darwin’s return to England. He became a transmutationist in 1845 after reading Chambers’ (1844) Vestiges of the Natural History of Creation. From 1848 to 1852, Wallace conducted fieldwork in the Amazon basin with Henry Bates, making investigations and collections in all departments of natural history. Setting out for the East Indies in 1854, he once again benefited from having already accepted transmutation, so that he was ready to interpret the phenomena he observed in that context. Wallace, like Darwin, needed a mechanism of transmutation, but unlike Darwin he did not delay in publishing his incomplete views. In 1855 he wrote and published in the Annals and Magazine of Natural History what is known as his Sarawak paper. In it he stated that new species come into being near in time and space to allied species, but without supplying a mechanism for their origin.
The paper received little public attention. Darwin thought it just another vaguely transmutationist work. The geologist Charles Lyell, however, thought it very important, and said so to Darwin. In 1856, Darwin explained his theory to Lyell, and Lyell pressed him to begin his “big book on species”. And so, Darwin did.
It was while working on this “big book” (eventually published in 1975 as Natural Selection) in June of 1858 that Darwin received from Wallace his famous “Ternate paper”, in which Wallace formulated his theory of evolution by natural selection. Darwin could not, of course, have stolen the idea of natural selection itself from Wallace, for, as we have seen, it had been demonstrably laid out by Darwin almost two decades earlier. The idea Darwin’s detractors most suspect of having been stolen from Wallace is the “principle of divergence”, the chief import of which is that ecological specialization can drive divergence, and thus lead to a multiplication of species in the same locality. Kohn (1981, 1985) and Kottler (1985) have analyzed this concept in some detail. As Kohn notes, Darwin included in this principle several ideas (the branching nature of phylogeny, sympatric speciation, interspecific interactions, ecological specialization) which, while familiar enough individually, do not to us today seem to form an ineluctable whole.
Both Kohn and Kottler consider Darwin’s and Wallace’s concepts of divergence significantly different, so that Darwin could not have gotten his ideas from Wallace. Kottler argues that in his Ternate paper, Wallace considered only linear or phyletic divergence (i.e., anagenesis), while Darwin’s principle embraced not only this, but branching divergence as well (i.e., cladogenesis, the divergence of two or more species descended from a single common ancestor). Kohn concludes that Darwin had formulated his principle of divergence by January 1855; Darwin (1958), in his autobiography, implies he had done so by early 1856; according to Kottler, Darwin had formulated his principle by 1857 at the very latest. By any of these datings, Darwin could not have been influenced by the Ternate paper of 1858.
If we look at readily available archival materials, we can see that most of the parts of Darwin’s concept were already present in his writings well before Wallace published anything. In his ‘B’ notebook, written in the late 1830s, Darwin includes his first sketches of the branching tree (or coral) of life (Darwin, 1987:177, 180). In the ‘D’ notebook, in September 1838, he uses the metaphor of the “wedge”, with every species trying to fill gaps in the economy of nature (Darwin, 1987:375-6). And, in a note dated January 1855, he writes of “diversity of structures supporting more life” (i.e. ecological specialization leading to greater diversity) (Kohn, 1985:256). I thus do not see that Wallace, in either the Sarawak or Ternate papers, supplied anything wanting in Darwin’s conceptual armamentarium. It takes nothing from the perspicacity of Wallace, or the import of his views for the world at large, to conclude, as do both Kohn and Kottler, that for Darwin, Wallace’s Ternate paper was an “intellectual non-event”.
When Wallace sent his paper, he asked Darwin to pass the paper on to Lyell. Darwin was much distressed by the paper, as it contained, he thought, his own views in miniature, even though more sober reflection revealed a number of differences in their formulations of the concept (Kottler, 1985; Shermer, 2003). Darwin passed the paper on to Lyell, not wanting to do anything unfair to Wallace, but at the same time not wanting his own 20 years’ work to go unrecognized.
Darwin was much distracted at this time by an outbreak of disease in his household, in which several fell ill, and his son Charles Waring died (his funeral was on July 1, the day the papers were read at Burlington House). Lyell and Hooker arranged for a reading of Wallace’s paper, along with an excerpt from Darwin’s Essay and a letter from Darwin to Asa Gray written in 1857, at the next meeting of the Linnean Society, which was on July 1. In presenting them, Lyell and Hooker arranged them, delicately perhaps, in chronological order (Burkhardt and Smith, 1991:107-128).
Darwin’s detractors argue that Darwin stole the principle of divergence when he received Wallace’s Ternate paper, that he lied about exactly when the manuscript and other of Wallace’s correspondence arrived, and that he destroyed letters to cover up his actions.
The first of these claims is, as we have already seen, belied by the fact that Darwin had by this time already formulated his principle of divergence. The second is based on the unproven assumption that Wallace’s letter was posted on March 9 (which would get it to London on about June 3). But as Shermer (2003:133) suggested, and van Wyhe and Rookmaaker (2012) have demonstrated, had it been posted on the April mail steamer, it would have arrived at Down House on June 18, precisely when Darwin said it did (Burkhardt and Smith, 1991:107-108). And, given that Wallace’s letter referred to a matter which he did not learn of till the arrival of the March 9 mail steamer, it is more likely that his manuscript and letter were posted on the April mail steamer ( van Wyhe and Rookmaaker, 2012). The third is based on unfamiliarity with the circumstances under which Darwin’s correspondence was saved and stored: Darwin used to routinely cut up his correspondence, saving relevant portions in topical folders, while discarding the rest, especially before 1862, and significant parts of what he did save were later lost to water damage (Kohn, 1981).
Finally, even if Darwin did not steal anything from Wallace, or lie about it, was it not unsavory to have Darwin’s excerpts published along with Wallace’s paper? Again, I think not. At the time of the arrival of Wallace’s paper, Darwin was well along writing Natural Selection (he suspended work on it, writing over the next year the ‘abstract’ that became the Origin.) Wallace did not ask that Darwin publish his paper, but that he should show it to Lyell. Darwin, had he wanted to be unfair to Wallace, could easily have read it, sent it on to Lyell, gotten it back, and then returned it to Wallace, with the advice that it was indeed worth publishing, and that if Wallace would revise and return it, he (Darwin) would submit it forthwith for publication. Given the delays involved in correspondence with the East Indies, it might have taken six months for such an exchange to occur (Raby, 2001), giving Darwin ample time to publish his views before Wallace. And if Darwin were so malicious, he could simply have not showed the letter and manuscript to anyone (Shermer, 2002: 132).
Lyell and Hooker’s actions in fact advanced the publication of Wallace’s views further than Wallace could have hoped. On the other hand, not to publish Darwin’s views at the same time would have been a grave injustice to Darwin, since Lyell and Hooker knew that Darwin had been working on the species problem for many years, and had a much more substantial, though incomplete, manuscript in hand. Had Wallace been published alone, and received sole credit for natural selection, it would be regarded today as a much more curious and unjust turn of events than what did transpire.
Simultaneous publication was a “win-win” situation for Darwin and Wallace (1). Darwin established that he in fact had thought of natural selection first, and also received a strong stimulus to complete a fuller presentation of his views. Wallace established that his discovery of natural selection was, though later, entirely independent of Darwin’s. The circumstances allowed Wallace to later rightly insist that he not be classed with those forerunners, such as W.C. Wells and Patrick Matthew, who stated the principle of natural selection, but “failed to see its wide and immensely important applications” (1870:iv): Wallace did see its wide and immensely important applications.
Simultaneous publication gave Wallace the nihil obstat of Darwin, Lyell and Hooker, and thus a guarantee that his paper would be read and taken seriously, and not be overlooked, as he thought his Sarawak paper had been. Indeed, over and over again, Wallace expresses his satisfaction and, indeed happiness, over the arrangements made by Hooker and Lyell (Shermer, 2003; van Wyhe, 2013). Wallace wrote home that their action “insures me the acquaintance of these eminent men on my return home” (Wallace, 1905, I:365). Later, Wallace (1908:193) wrote, “I not only approved, but felt that they had given me more honour and credit than I deserved.” After learning what had been done, Wallace wrote to Hooker (6 October 1858: Burkhardt and Smith, 1991:166):
Allow me in the first place sincerely to thank yourself & Sir Charles Lyell for your kind offices on this occasion, & to assure you of the gratification afforded me both by the course you have pursued, & the favourable opinions of my essay which you have so kindly expressed. I cannot but consider myself a favoured party in this matter, because it has hitherto been too much the practice in cases of this sort to impute all the merit to the first discoverer of a new fact or a new theory, & little or none to any other party who may, quite independently, have arrived at the same result a few years or a few hours later.
Note that Wallace expresses satisfaction at being recognized at all, since the convention of the day was that credit went to the first discoverer rather than the first publisher of the discovery.
Van Wyhe (2013) summarizes:
In fact, none of Wallace’s statements indicate any dissatisfaction or disappointment. They contain only disarming qualifications that the work before the public had not been checked by him in proof. We could not expect a clearer or more unguarded indication of how Wallace received the news of the arrangement than the letter to his mother after learning the news. He told her that “Dr. Hooker and Sir C. Lyell… thought so highly of it that they immediately read it before the Linnean Society”. They thought so highly of it they had it immediately read! And that’s that. No matter how many times Wallace said how happy he was with the Linnean arrangement (and we have many instances), and how much he thought he benefited more than he deserved, this does not deter some Wallace fans from feeling aggrieved. Indeed, given how overwhelmingly advantageous the joint publication was for Wallace, it is hard to see how he could have regarded it as anything but positive and fortunate — which is how he described it in all of his later recollections. Wallace remarked in 1903, “My connection with Darwin and his great work has helped to secure for my own writings on the same questions a full recognition by the press and the public; while my share in the origination and establishment of the theory of Natural Selection has usually been exaggerated.” “It was really a singular piece of good luck that gave to me any share whatever in the discovery.” He felt he had received “ample recognition by Darwin himself of my independent discovery of ‘natural selection’”. And in his autobiography, Wallace stated that he “obtained full credit for its independent discovery”.
In the event, there was little reaction to the Linnean Society papers. The Linnean Society president, the herpetologist Thomas Bell, (in)famously remarked about the Society’s activities for 1858-1859 that, “The year which has passed has not, indeed, been marked by any of those striking discoveries which at once revolutionize, so to speak, the department of science on which they bear”. It was Darwin’s glowing mention of Wallace on page one of the Origin, in which Darwin stated that Wallace had arrived at “the same general conclusions” in his “excellent memoir”, that firmly established Wallace as the co-discoverer of natural selection and a leading figure in the new evolutionary biology.
Although the circumstances of independent discovery could have led to an ugly dispute about priority, they did not. Both Darwin and Wallace realized the value and nature of each other’s contributions, and both were content to share credit with the other. Although they later differed on a number of issues (Kohn, 1985; Kottler 1985; Shermer 2002), they remained friends and colleagues for life, standing figuratively side by side, fighting together the intellectual battle for their theory of evolution by natural selection against its many and powerful foes.
(1) In a striking coincidence, entirely independently of my usage of “win-win” in my 2002 essay, Shermer (2002), used the exact same words to describe his own view of the circumstances of publication, and elaborated on the notion of science as a “plus-sum game”. He writes (p. 148) of Darwin and Wallace of “the special win-win nature of their relationship”; although I demurred at the suggestion, the editor of my essay proposed I entitle it “Darwin and Wallace: A “win-win” relationship”!
_______________________________________ The preceding is adapted from a published paper (Mayer, 2002) which, in turn, was based on an earlier paper that was presented before the Malay Archipelago Reading Group of the Department of Zoology, University of Wisconsin, Madison. I am grateful to the members of that group, and especially Sher Hendrickson, for the opportunity to have done so, and for stimulating me to write the original essay. John Van Wyhe has kindly shared with me excerpts from his recent book and read and commented on this revision. Props to anyone who gets the Star Trek allusion in the title.
Chambers, R. 1844. Vestiges of the Natural History of Creation. London: Churchill. DO
Darwin, C.R. 1859. On the Origin of Species. London: John Murray. DO
Darwin, C.R. 1909. The Foundations of the Origin of Species. Two Essays Written in 1842 and 1844. F. Darwin, ed. Cambridge:
Cambridge University Press. DO
Darwin, C.R. 1958. The Autobiography of Charles Darwin 1809-1882. N. Barlow, ed. New York: W.W. Norton. DO
Darwin, C.R. 1975. Charles Darwin’s Natural Selection. R.C. Stauffer, ed. Cambridge: Cambridge University Press. DO
Darwin, C.R. 1987. Charles Darwin’s Notebooks 1836-1844. P.H. Barrett, P.J. Gautrey, S. Herbert, D. Kohn and S. Smith, eds. Ithaca, N.Y.: Cornell University Press. DO
Darwin, C.R. and Wallace, A.R. 1858. On the tendency of species to form varieties; and on the perpetuation of varieties and species by natural means of selection. Journal of the Proceedings of the Linnean Society. Zoology 3:45-62. WO
Davies, R. 2008. The Darwin Conspiracy: Origins of a Scientific Crime. London: Golden Square Books. pdf
Kohn, D. 1981. On the origin of the principle of diversity. Science 213:1105-1108.
Kohn, D. 1985. Darwin’s principle of divergence as internal dialogue. Pp. 245-257 in D. Kohn, ed. The Darwinian Heritage.
Princeton, N.J.: Princeton University Press.
Kottler, M.J. 1985. Charles Darwin and Alfred Russel Wallace: two decades of debate over natural selection. Pp. 367-432 in D. Kohn, ed. The Darwinian Heritage. Princeton, N.J.: Princeton University Press.
Mayer, G.C. 2002. Darwin and Wallace at Burlington House. BioQuest Notes 11(2):1, 10-13. pdf
Quammen, D. 1996. The Song of the Dodo. New York: Scribner.
Raby, P. 2001. Alfred Russel Wallace: A Life. Princeton, N.J.: Princeton University Press.
Ruse, M. 1999. The Darwinian Revolution. 2nd ed. Chicago: University of Chicago Press.
Wallace, A.R. 1855. On the law which has regulated the introduction of new species. Annals and Magazine of Natural History 2nd Ser. 16:184-196. WO
Before writing my notice of John van Wyhe’s new book on Wallace, Dispelling the Darkness, I hadn’t come across this piece by him on Wallace in last week’s Guardian. The piece addresses and dispels the claim, advanced a number of times over the years—especially in popular media—that Darwin stole his ideas from Wallace, and that there was an unsavory conspiracy to rob Wallace of proper credit. This is a view that has gotten some recent attention, and John deals with it head on. The short answers: he didn’t steal, and there wasn’t a conspiracy.
Do read the whole piece. Some excerpts:
Wallace deserves more attention but much of what you will have heard about him in the last few months is factually incorrect – and amounts to a misguided campaign to reinstate the reputation of a genius who (according to his fans) has been wronged by history and robbed of his rightful fame….
Darwin’s life and works have been meticulously studied by many scholars for over a century. But while some very able scholars have studied Wallace, he by contrast has remained mostly the preserve of amateurs and enthusiasts.
There has not been enough progress with our understanding of Wallace because some of the important research projects that have unveiled a treasure trove of new findings about Darwin had never been done for Wallace: his complete works had not been assembled on one scholarly website, his Malay archipelago expedition correspondence had not been collected and edited and his notebooks and journals had not been edited and their contents made intelligible.
All of these have recently been done, the latter two not yet published. These new sources have shown us that every substantive claim in the popular narrative about Wallace turns out to be incorrect.
And the money quote:
Darwin’s fame and reputation, and Wallace’s comparative obscurity, stem from the impact of Darwin’s Origin of Species. As Wallace himself wrote: “this vast, this totally unprecedented change in public opinion has been the result of the work of one man, and was brought about in the short space of twenty years!”
For my take on the second of these questions, which very much agrees with John’s, see my post on “Why is Darwin more famous than Wallace“. In attempting to promote Wallace, these modern admirers, perhaps unwittingly, portray Wallace as a hapless chump who was unaware of his own contributions. He was neither of these things.
It was thus with great pleasure that I read a recent paper by Jeremy Austin and colleagues (ref below, news piece here) on the Falkland Islands fox or wolf (Dusicyon australis), a species which had intrigued Charles Darwin, and which he wrote about in the Zoology of the Beagle, the Voyage of the Beagle, and The Origin.
But first, let’s recap the features of island faunas that Darwin thought cried out for an evolutionary explanation. In examining island faunas, Darwin distinguished between continental islands, which had had a connection to a mainland in the recent past (e.g. Great Britain, which was connected to France by Ice Age sea-level lowering as recently as about 12,000 years ago), and oceanic islands, which had never had a connection to the main (e.g. mid-ocean volcanic islands like the Galapagos).
Darwin identified four characteristics of oceanic islands, which I like to call the “four D’s”. First, island faunas are depauperate— they hold fewer species than did comparable areas of mainland habitat. Second, they are disharmonious— they are inhabited by an unusual concatenation of taxa, rather than the usual combinations of predators, herbivores, and omnivores. Instead of cattle and deer, the large herbivores of islands were things like giant tortoises (as in the Galapagos) or giant geese (as in Hawaii). And large predators, such as cats and dogs, were usually lacking altogether (although some islands had very large birds of prey). Third, island faunas showed signs of dispersal— the animals that were there showed the ability to cross salt water. So birds and bats were usually present, but large land mammals and amphibians were usually absent. And finally, there was a strong effect of distanceon the character of the fauna– the Galapagos fauna, for example shows clear affinity to the Americas, while the fauna of the similarly situated but Atlantic archipelago of Cape Verde shows affinity to Africa.
Darwin argued that all of these features can be explained if the inhabitants of oceanic islands are the modified descendants of animals that had been able to disperse there. These animals would need be susceptible to occasional means of transport (dispersal), come from the most accessible mainland (distance), and would be a small, non-representative sample of what occurred on the mainland (disharmonious, depauperate). Darwin contrasted this with what we might expect under an hypothesis of special creation. Why were the island faunas “undercreated” relative to the mainland, and why would they bear the plain stamp of affinity to the nearest mainland, rather than being related to the faunas of other similar islands?
Although we all associate Darwin with the Galapagos, Darwin also visited the Falklands, and they supplied, I believe, an important bit of evidence in his thinking about islands. Darwin was a bit perplexed about the Falklands. In many ways they seemed like oceanic islands. There was only a single species of land mammal, the Falkland Islands fox, which was clearly related to South American foxes (South America has a modest radiation of canids, which are variously called dogs, foxes, or wolves in English). The mammal fauna thus shows 3 of the four D’s: depauperate, disharmonious, and distance.
An alternative explanation for island faunas being depauperate and disharmonious is that the ecological conditions on the islands are unsuitable, despite seemingly appropriate physical environmental conditions. This alternative explanation is easily tested by introducing exotic species to the island, and seeing how they fare. If they become established, then the cause of their absence is a failure of dispersal, not a failure of environmental suitability. This is where the Falklands helped Darwin, I think. The Galapagos in the 1830s were still nearly pristine, but the Falklands showed him the fauna of an island with little direct habitat disturbance and a small human population, but whose population had brought their animals with them. At the time of his visit, Darwin recorded wild populations of cattle, horses, pigs, rabbits, rats, and mice, with feral cats and at least domestic dogs and sheep coming later. The Falklands were thus quite capable of supporting a diverse and harmonious mammalian fauna; the mammals just needed help getting there. (The increasing human population, and consequent increased disturbance and hunting, led to the extinction of the Falklands fox by the late 1800s.)
But how did the fox get there? Carnivores, in general, are not known to be good at dispersing across sea barriers, and a fox is unlikely to have been able to cross several hundred kilometers of open sea. This is what puzzled Darwin, and led him to suggest that the islands had been connected to the continent, despite the lack of all other animals that might have been expected to cross over on a land bridge. In later years, it was even suggested that the fox was semi-domesticated, and had been brought to the islands by Indians. This is where the latest paper by Austin et al. comes in.
As I noted above, South America is home to a modest radiation of canids, but the closest living relative of the Falklands fox, the maned wolf (Chrysocyon brachyurus), is not very close, with an estimated divergence time of 7 million years ago. What Austin and colleagues have done is extract DNA from fossils of Dusicyon avus, a very recently extinct canid (ca. 3ooo years ago) that was widespread in southern South America. Comparing their DNA to that from skins of the even more recently extinct Falklands fox, they found that the two are very closely related. Indeed, in their best phylogenetic estimate, the mainland avus is paraphyletic with respect to australis, and this is exactly what we would expect if the Falklands had been colonized by mainland foxes from the part of South America nearest to the islands. Furthermore they were able to date the divergence to 16,000 years ago– the height of the last glacial maximum. As is well known, the glaciers withdrew massive amounts of water from the sea, lowering sea levels by about 120 m. Looking at the seabed between the Falklands and the main, we can see that a 120 m lowering would substantially reduce the distance between them. Austin and colleagues favor an even greater lowering, further reducing the distance, but either lowering would reduce the distance to the order of tens, rather than hundreds, of kilometers.
But could a fox cross even tens of kilometers of sea? Yes– on ice floes or sea ice. How do we know? The arctic fox (Vulpes lagopus) ventures way out on to the sea ice, and can float out on ice floes, having been recorded as turning up occasionally in eastern Canada, far to the south of its native range. It is also the only native land mammal of Iceland, an island which has never had a continental land connection, and which it must have reached on ice floes. Darwin himself noted the possibility of ice transport, writing in the Origin “icebergs formerly brought boulders to its [Falklands] western shores, and they may have formerly transported foxes, as so frequently now happens in the arctic regions.”
So Darwin’s dilemma is solved. Glacial sea-level lowering and sea ice provide an “occasional means of transport”, and the fossil record and DNA analysis lead to an identification of the ancestor, and dating of the event to the precise time when such means were most available.
Austin, J.J. et al. 2013. The origins of the enigmatic Falkland Islands wolf. Nature Communications 4(1552). (pdf, subscription required)
Darwin, C.R. 1859. On the Origin of Species. London: John Murray. (DOL)
Darwin, C.R. 1860. Journal of Researches into the Natural History and Geology of the Countries Visited During the Voyage of H.M.S. Beagle Round the World. Last revised edition. London: John Murray. (DOL)
Matias, R. and P. Catry. 2008. The diet of feral cats at New Island, Falkland Islands, and impact on breeding seabirds. Polar Biology 31:609-616. (pdf)
Waterhouse, G.R. 1838. Mammalia. The Zoology of the Voyage of H.M.S. Beagle, under the Command of Captain Fitzroy, During the Years 1832 to 1836. Part 2, No. 1. (BHL, DOL)
The first publication of natural selection as a general mechanism of evolutionary change was a joint paper by Darwin and Wallace read to the Linnean Society in 1858. It was not a coauthored paper, but rather the simultaneous publication under a single heading of separate works by the two authors. So why does everyone know Darwin’s name, but hardly anyone knows Wallace’s?
My first reaction to the question is usually to say “But everyone does know about Wallace!” But I do find that even many biologists—especially if they are not evolutionary biologists—know little or nothing about Wallace. And in the culture at large, Darwin is well-known while Wallace is virtually invisible. (Since, at least in the United States, “Darwin” is a curse word to large swaths of the population, this may not be a bad thing for Wallace!) So there does need to be an analysis of the question of Darwin and Wallace’s relative contributions and recognition, and why Darwin is better known.
And the short answer is that their joint paper aroused little or no interest– it slipped into the waters of English natural history with scarcely a ripple. Thomas Bell, author of the herpetological volume of the Zoology of the Beagle and president of the Linnean Society in 1858, wrote at the end of the year that the Society had published no papers of special import during the year. It was the publication of the Origin of Species by Darwin the following year that made a splash heard round the world.
And there were several reasons for this: it was a work of monumental compilation and argumentation, eagerly anticipated by the leading lights of natural history both in Britain and abroad, and by a well respected and well known naturalist. It was the Origin, in fact, that forever associated Wallace with natural selection, through Darwin’s acknowledgment of Wallace’s co-discovery on page 1. Wallace himself always accepted that Darwin was primus inter pares.
The BBC piece follows the main currents of historical thinking in this regard, but makes two points worth emphasizing. First, it notes that Wallace was very well known in his lifetime, and that by virtue of his outliving Darwin he was for 30 years the sole surviving discoverer of natural selection, which enhanced his status and recognition from 1882 to 1913.
Second, it notes what Julian Huxley called the “eclipse of Darwinism”, a period in the decades around 1900 when natural selection (but not evolution) fell into disfavor (a period about which the historian Peter Bowler has written extensively), and that when natural selection was revalidated during the Modern Synthesis, Darwin was given more credit than Wallace. What is not noted in the BBC piece, but which I think may be significant, is that during the “eclipse” period, it was natural selection (i.e., Darwin and Wallace) that came under fire, but not evolution; and it was Darwin, much more so than Wallace, who convinced the world of evolution per se. So, during the “eclipse” period, Darwin was recognized for demonstrating evolution, but faulted for his mechanism of adaptive change (even T.H. Huxley sometimes inclined in this direction). In contrast, Wallace, whose chief contribution was natural selection, would simply be faulted. (Wallace’s many other contributions, especially in biogeography, were of course noted and lauded.)
The only thing that seemed off about the BBC piece was the title. Darwin did not “eclipse” Wallace, i.e., Wallace was not a shining star that some later passing dark object (Darwin) obscured. Rather, both were luminescent, and Darwin’s star had indubitably begun burning before Wallace’s. The question, then, is why was Darwin, on the public stage, more luminious than Wallace? But I suppose that the headline writer (who is almost always not the reporter) was trying to allude to the “eclipse of Darwinism” discussion, and it’s a small fault in an otherwise fine piece.
Bowler, P.J. 1992. The Eclipse of Darwinism: Anti-Darwinian Evolution Theories in the Decades around 1900. Johns Hopkins University Press, Baltimore.
Bowler, P.J. 2005. Revisiting the eclipse of Darwinism. Journal of the History of Biology 38:19-32. (abstract only)