Baden Powell (1796-1860)
The Reverend Baden Powell, Savilian Professor of Geometry at Oxford University, was a powerful clerical voice for the compatibility of evolutionary hypotheses and religious (specifically Christian) beliefs. Powell argued that there can be no exceptions to the laws of the natural world, and this placed him at odds with conservative forces within the hierarchy of the Church of England. As Powell stated forcefully in The Unity of Worlds and of Nature: Three Essays on the Spirit of the Inductive Philosophy; the Plurality of Worlds; and the Philosophy of Creation :
“That new species should be subject to exactly the same general laws of structure, growth, nutrition, and all other functions of organic life, and yet in the single instance of their mode of birth or origin should constitute exceptions to all physical law, is an incongruity so preposterous that no inductive mind can for a moment entertain it.” (page 377, The Unity of Worlds, 1855).
Baden Powell is also the father of the founder of the Boy Scouts, Robert Baden-Powell (his third wife changed the family name to a hyphenated version of Baden Powell). Read more about Baden Powell’s contributions to evolutionary thought.
Baden Powell’s insistence on the investigative natural sciences as being essential to Christian natural theology (evidence for the existence of God derived from observations of the natural order) came at a time when the theological underpinnings of the Church of England were the subject of significant debate. His strong interest in the question of whether the world was an evolutionary one can first be traced to his 1838 essay, Connexions between Natural and Divine Truth (a response to the 1837 Bridgewater Treatises). Here, Powell broaches the species question – writing that the immutability of species is open to “philosophical investigation.”:
“The question respecting the immutability of species, and the possibility of a transition from one into another; of such modifications as we observe in intermediate races being perpetuated; of new species being thus eventually introduced; with the various collateral topics which are involved in these inquiries, have all formed the subjects of anxious debate, and even of animated controversy, among physiologists.” (page 150, Connexions, 1838).
Here is clear evidence of the extent to which species transmutation theory had permeated England’s intellectual atmosphere more than two decades before the publication of Charles Darwin’s On the Origin of Species.
In 1845, Powell authored an entry entitled “Creation” in John Kittos’s Cyclopaedia of Biblical Literature. After elucidating the current state of scholarly biblical exegesis on the Genesis creation story, Powell recounts various “theories” of creation based alone or in part on the scriptural account of creation; and he compares these with geological and fossil evidence for the appearance of life on Earth:
“As bearing then, on the subject of creation, or the origin of life and organized structures, the whole evidence which geology furnishes is certainly irreconcilable with the idea of one simultaneous general development of organized existence. It points, indeed, to a commencement of organized life; but shows that as successive forms and species of organization from time to time disappeared, new forms and new species were produced to supply their places; [that these changes corresponded to others in the physical conditions of the globe; but that none of them were at once universal in extent and simultaneous in time; lastly, that the human race (probably) did not come into existence till the period to which the present state of things belongs]”(page 484, Cyclopaedia of Biblical Literature, 1845).
As would become even more evident in his later writings, the rapidly expanding and detailed geological and fossil record was central to his argumentation for an evolved world.
In 1855, Powell expanded on his earlier writings in a full-length book – The Unity of Worlds and of Nature: Three Essays on the Spirit of Inductive Philosophy; The Plurality of Worlds; and The Philosophy of Creation. In considering Powell’s contribution to and engagement with early evolutionary thought, his third essay, The Philosophy of Creation, requires particular consideration. The essay is divided into four parts: Evidence from Geology, Evidence from Physiology, General Considerations, and Bearing on Theological Views. The first two sections, in which Powell gives evidences for species transmutation from geology and physiology, draw heavily upon Lyell’s gradualism and uniformitarianism. Powell derived the majority of the physiological evidence from works of Owen, Carpenter, and Huxley (although he mentions Knox and others as well). As Darwin would do in Origin, Powell defends gaps in the fossil record as periods of poor preservation:
“If then, we find a bed containing certain species, and then superimposed on it another containing forms not only specifically, but even generically or still more widely different, instead of a real hiatus, an interruption, a destruction, and a sudden reproduction of life, the fair inference would be the occurrence of an indefinitely long interval of ages, during which, indeed, no fossiliferous deposits took place at that locality, but during which the slow progressive change of species went on, until whole genera were different, and then a deposit took place in which some of these latest remains were imbedded” (page 365, The Unity of Worlds, 1855).
Following the publication of On the Origin of Species, Darwin wrote to Powell in January of 1860 (presumably in response to Powell reminding him of his own contributions to evolutionary theory– letter lost) that “I have just bethought me of a Preface which I wrote to my larger work, before I broke down & was persuaded to write the now published Abstract. In this Preface I find the following passage, which on my honour I had as completely forgotten as if I had never written it. “The Philosophy of Creation” has lately been treated in an admirable manner by the Revd. Baden Powell in his Essay &c &c 1855. Nothing can be more striking then the manner in which he shows that the introduction of new species is “a regular not a casual phenomenon” (Letter).
In fact, Baden Powell was invited to participate in the now famous 1860 Oxford evolution debate (in which Wilberforce and Huxley debated Darwin’s theory), but died of a heart attack two weeks before it was held. As the historian Pietro Corsi writes in Science and Religion: Baden Powell and the Anglican Debate, 1800-1860, “He [Powell] had become the most outspoken representative of liberal theology and the evolutionary approach to natural history. His sudden death, on 11 June 1860, deprived him of the possibility of linking his name with the evolutionary debate as the first outspoken theological supporter of Darwin’s theory”.
Although Powell wrote on similar themes throughout his life, he, perhaps spurred on by his zeal for educational reform in the university and desire to participate in the scientific discussions of the day, became increasingly outspoken in his adherence to the conclusions drawn from “inductive philosophy”, or empiricism. His 1859 publication Order of Nature rejected the reality of miracles, and was denounced by the Anglican church as marking a departure from accepted doctrine.
Despite being an ardent advocate of evolutionary theory, not every naturalist found Powell’s contributions to the evolutionary discussion wholly satisfactory. Darwin’s close friend and confidant Joseph Dalton Hooker wrote to the American botanist Asa Gray in 1857: “These parsons are so in the habit of dealing with abstractions of doctrines as if there was no difficulty about them whatever, so confident, from the practice of having the talk all to themselves for an hour at least every week with no one to gainsay a syllable they utter, be it ever so loose or bad, that they gallop over the course when their field is Botany or Geology as if we were in the pews and they in the pulpit. Witness the self-confident style of Whewell and Baden Powell, Sedgewick, and Buckland” (pages 477-478, Life and Letters of Sir Joseph Dalton Hooker).
To read more about the botanist Joseph Hooker’s contribution to evolutionary thought, click here.
Jean Baptiste Julien d‘Omalius d’Halloy (1783-1875)
Jean Baptiste d’Omalius d’Halloy was a Belgian geologist and wealthy Catholic aristocrat who became one of the best known advocates of evolutionism in Belgium and France in the mid-nineteenth century. His conservative credentials and rejection of strict materialism would enhance the reception of evolutionary thought.
As a young man, d’Omalius moved to Paris and studied under Lamarck and other French evolutionists including LaCepede and Etienne Geoffroy St. Hilaire). Beginning in 1831, d’Omalius argued in his Elements de Geologie that the fossil record could best be explained by a theory of evolution (as opposed to a series of mass extinctions and subsequent independent creations). d’Omalius also made reference to human domestication (‘interference”) of animals and plants as an analogue for understanding evolutionary diversification over greater periods of time. [For a good English translation of some of the important parts, see pages cclxxiv – cclxxvii in Vyvyan’s On the Harmony of Worlds, 1845]. In the 1840s and 1850s, d’Omalius published a number of papers on the succession and modification of living beings (e.g., 1846, Note On the Succession of Living Beings). Ultimately, d’Omalius, while not rejecting Darwin and Wallace’s principle of natural selection, viewed it as being unable to account for large morphological changes over the course of geological time.
For an excellent treatment of d’Omalius d’Halloy, his ideas on evolution, and the broader societal context of his evolutionism please read: de Bont, R. 2007. A serpent without teeth. The conservative transformism of Jean-Baptiste d’Omalius d’Halloy (1783-1875). Centaurus 49: 114 – 137. pdf here
Charles Naudin (1815-1899)
Charles Naudin was a French botanist who studied hybridization and heredity over the course of his long life. In 1852, he published a paper on evolution entitled “Considérations philosophique sur l’espèce et la variété” (Philosophical considerations on species and varieties) in Revue Horticole. In this important paper, Naudin writes that artificial selection is essentially based upon nature’s process of selection and that the line between species and varieties is artificial. In addition, Naudin wrote of deep time and the progressive nature of the fossil record, and critically, that life should be classified based on genealogy.
After On the Origin of Species was published (1859), Darwin received a letter from the French botanist Joseph Decaisne, who argued that Naudin had already advanced the central ideas of artificial and natural selection. Darwin was sufficiently miffed by this letter (no longer extant) to write (letter here) his good friend and colleague Joseph Hooker (December 23, 1859): “I am surprised that Decaisne shd say it was same as mine. Naudin gives artificial selection as well as a score of English writers; & when he says species were formed in same manner I thought the paper would certainly prove exactly the same as mine. But I cannot find one word like the Struggle for existence & Natural Selection.”
Even some of Naudin’s French contemporaries agreed with Darwin. The French biologist Jean Louis Armand de Quatrefages called Naudin’s conception closer to that of his French countrymen Buffon, Lamarck, and Bory de Saint Vincent; and wrote that Naudin had failed to penetrate the crux of the species problem, in contradistinction to Darwin. Quatrefages (1870) wrote that Naudin’s work neglected to explain the actual process by which nature selected new variations generated in the hereditary process and left open the question of whether selection was driven by “an intelligent nature, acting with a view to a determined goal” or the directionless “natural selection” postulated by Darwin.
In fact, one finds in Naudin’s work that species formation is attributed to the interplay of two opposing forces – atavism, or the hereditary conservation of ancestral characteristics, and plasticity, or the creation of new heritable morphologies. A precise role for these two counteracting forces is not delineated; however, Naudin did express a belief that early phases of life had been more plastic, allowing for original creations to “subdivide into secondary types,” while atavistic forces increased with the progress of time, restricting the breadth of new types that could evolve. Despite differing conditions between the past and present as well as between nature’s resources and man’s, Naudin held that the process by which new species came into being was essentially the same, and that it could be compared to the process by which the horticulturalist created new varieties of plants:
“We do not believe that nature has proceeded to form its species in a manner that we ourselves use to create our varieties; rather, it is nature’s process that we have applied to our practices… [T]o start a new lineage, we choose among the large number of individuals… those that seem to deviate from the specific type in ways that suit us, and, with a rational selection and follow up of the products obtained, we do, after an undetermined number of generations, create artificial varieties or species that meet more or less the ideal type that we were aiming for… Such, in our ideas, is the course followed by nature; like us, it wanted to form races to fit them to its needs; and with a relatively small number of primordial kinds, it successively gave birth and at various times, to all the plant and animal species that inhabit the globe… Nature has operated on a huge scale and immense resources. We, on the contrary, we do so with extremely limited means; but between its processes and ours, between its results and those we get, the difference is all in quantity; between its species and those we create, there are only the more and less.”
What appears to be evident in this passage is that the process of selecting in nature is likened to the process of domestication with a guiding hand and a goal (“nature, like us, it wanted to form races to fit them to its needs”). This distinctly teleological process is radically different from what Darwin and Wallace (at least Wallace until the mid-1860s) would propose as an unguided mechanism of natural selection.
No doubt Naudin’s extensive horticultural and plant-breeding experience (he crossed approximately 2,000 cucurbit varieties in an effort to clarify familial relationships) led to his conclusion that the relationships among species were best viewed as a branching tree. Furthermore, he proposed that this image worked because the relationships were real – all life could be considered and grouped into genealogical communities of descent. Here, his view of life undoubtedly overlaps with Darwin’s.
“[A] perfect and rigorous classification of organic beings of the same kingdom, same order, same family, would be nothing other than the genealogical tree of the same species, indicating the relative ancientness of each, degré de spéciéité [unifying characters?], and line of ancestors from which it is descended.”
The reason for the persistence of particular species in time was obscured by Naudin’s references to the force of “finality,” an essentially teleological proposition which he equates with a “mysterious power… whose incessant action on living beings determines, in all ages of the existence of the world, the shape, volume, and duration of each of them, because of its destiny in the order of things to which it belongs.” As Darwin remarked in his letter concerning Naudin to Hooker, “he brings in his principle (p. 103) of Finality (which I do not understand) which he says with some authors is fatality, with others Providence, & which adapts the forms of every Being, & harmonises them all througout [sic] nature.”
Beyond his contributions to evolutionary thought, Naudin’s work (although perhaps unwittingly) played a role in the development of French art. In 1905, the French Fauvist artist Henri Matisse moved to the South of France, seeking consolation from emotional and mental distress. He visited Naudin’s Villa Palma gardens and the color and form there appear to have so inspired him that Naudin’s olive trees and palms, among other plants, are featured in Matisse’s stunning paintings of Collioure, France.
For a brief treatment of the life and intellectual contributions of Charles Naudin, click here.
Patrick Matthew (1790-1874)
Patrick Matthew, a Scottish arboriculturalist and fruit grower, remains an obscure figure in the history of early evolutionary thought. Nevertheless, as Darwin discovered unexpectedly in 1860, Matthew did publish a fully formed concept of the role of natural selection in 1831. Matthew’s ideas on the mechanism of evolutionary change appeared as a brief note in an appendix to a book entitled Naval Timber and Arboriculture (pdf here), which covered the then very important topic of how to grow, harvest and prepare trees for the building of ships. Darwin learned of this appendix upon reading “Nature’s law of selection” (written by Matthew, image below right) in the April 17, 1860 issue of the Gardeners’ Chronicle and New Horticulturalist. “In your Number of March 3d I observe a long quotation from the Times, stating that Mr. Darwin ‘professes to have discovered the existence and modus operandi of the natural law of selection.’ This discovery turns out to be what I published very fully and brought to apply practically to forestry in my work ‘Naval Timber and Arboriculture,’ published as far back as January 1, 1831.” Darwin could do little more than respond briefly and forthrightly in a letter published in the April 12 issue of the Gardeners’ Chronicle: “I freely acknowledge that Mr. Matthew has anticipated by many years the explanation which I have offered of the origin of species, under the name of natural selection. I can do no more than offer my apologies to Mr. Matthew for my entire ignorance of his publication.”
This episode offers tremendous insight into the issue of priority, the centrality of timing, and the importance of thorough documentation when advancing a new idea. Matthew’s concept of natural selection, like that of James Hutton in 1794, was buried in a longer work on other topics. It appeared well before the broader community of natural historians was prepared to integrate such an idea into its thinking about the sources of biodiversity. And importantly, this brief essay lacked the extraordinary documentation and reasoning that Darwin brought to bear on the topic of natural selection when he finally marshaled his vast intellectual resources to write On the Origin of Species more than twenty years after first coming up with the idea of natural selection.
For an excellent treatment of Matthew and his ideas on natural selection, please read: Wells, K. D. 1973. The historical context of natural selection: the case of Patrick Matthew. Journal of the History of Biology 6: 225 – 258.
Benoit de Maillet (1656-1738)
The French aristocrat and well-travelled diplomat, Benoit de Maillet is the author of the earliest evolutionary text in modern times. In a posthumously published book (the title, Telliamed, is the author’s name spelled backwards), de Maillet proposed that all terrestrial plants and animals were derived (transformed) from marine ancestors. The book is structured as a series of three speculative conversations between a French missionary and an Indian philosopher. In these conversations, De Maillet drew upon his extensive geological observations, his belief that the sea level was universally falling, and anecdotal evidence from many ancient and contemporaneous works of natural philosophy.
De Maillet’s highly polyphyletic version of evolution and the origin of terrestrial life was influential among French naturalists as a work of materialist philosophy. In Telliamed, the Indian philosopher, although portrayed as relating a fantastical tale to an incredulous French missionary – a device which makes the philosopher’s speculative views appear innocuous – actually represents De Maillet’s own sense of an evolutionary world. De Maillet is thought to have written the original text while serving as the French consul to Egypt in the early 1720s. Subsequent manuscript editions were subjected to significant modification by his editor the abbott Jean Baptiste de Mascrier. The work was not published until 1748, a decade after De Maillet’s death; and in many ways, the published text deviates from the original manuscript. De Mascrier’s edited version of Telliamed was quickly disseminated to the English-speaking world, where it was translated and published in London in 1750, only two years after its original publication. This same translation was then re-published in Baltimore, Maryland in 1797.
De Maillet’s transformist system of nature is situated within the context of his geological belief in a 2-billion-year-old Earth. As seas receded and terrestrial environments emerged, marine animals adapted (became transformed) to land. De Maillet believed that for every land animal, there is a “similar or closely related species in the sea” (184). He envisioned one possible transformation – that of the flying fish into the bird – and concluded that every species of bird had evolved from a corresponding fish with the “same form, color, and habits” (188). In the case of the flying fish which is accidentally confined to land, De Maillet imagined that a metamorphosis of its body structure could take place so its fins were transformed into wings (187). It is not clear whether de Maillet envisioned such transformations occurring in a single generation or over many successive generations. It is evident that his transformist views were inspired by examples of metamorphosis occurring in the lifetime of a single organism (e.g., caterpillar to butterfly).
De Maillet admited that some traits, such as speaking and writing, would take multiple generations to acquire. In speculating on the evolution of humans he wrote, “If males and females of these Orans-outans [Orangutans] had been captured…and had given birth to offspring among us, do you think Sir, that it might have been impossible, through a couple of generations, to make them capable of using a true language and reaching a more perfect shape than they originally had?” (202).
For De Maillet, correspondence of bauplan between sea and land organisms and the presence of life on remote islands were strong evidence that modern terrestrial life began in the sea (like several other early evolutionists, he vastly underestimated the effects of long distance dispersal to oceanic islands). He also thought that an animal’s habitat and ecology were important predictors of the marine species from which they had evolved. On the origin of life, it is worth noting that De Maillet believed that the germs of different types of species existed in space: “the seeds of all life already exist in the universe” and that new species could still come into being: “The globe we live on has certainly shown to us only a portion of the species of animals, trees, and plants whose seeds are contained in the surrounding air and sea, and we cannot doubt that the future centuries will reveal new and unknown ones” (228).
Darwin himself took note of de Maillet’s fanciful ideas of evolution, and, writing to a colleague who loaned him Telliamed in 1867, referenced Richard Owen’s scathing review of Origin. “I am bound to read it [Telliamed], as my former friend and present bitter enemy Owen, generally ranks me and Maillet [in his review of Origin] as a pair of equal fools.”
Jean-Baptiste Lamarck (1744-1829)
Lamarck remains the best known figure of the pre-Darwinian era of evolutionism. Regrettably, he is usually viewed as a mere caricature of his ideas, namely as the person who got it “wrong” for insisting on the inheritance of acquired features as the central mechanism of transmutation. Lamarck’s career and scholarly interests were both eclectic and diverse – and his ideas about evolutionary transformation were critical to the overall development of the discipline. Lamarck published the first dichotomous key of plants in 1778, went on to oppose the new chemistry of Lavoisier and others in the 1780s and 1790s, published annual meteorological predictions (not particularly accurate), and survived the purges of the French Revolution.
Although originally a botanist, Lamarck’s appointment in 1793 to the Museum d’Histoire Naturelle in Paris resulted in assigned responsibilities for invertebrates and microscopic organisms. In 1800, Lamarck gave a lecture in which he espoused the idea of evolution (published in 1801). In 1809, Philosophie Zoologique (Zoological Philosophy) the first book-length treatment of evolution was published. Remarkably, a full English translation did not appear until 1914 (pdf Part I, pdf Part II, pdf Part III). Lamarck embraced invertebrate zoology for much of the remainder of his career and ultimately wrote an important set of volumes on invertebrates between 1815 and 1822, which also contain his final views on evolution. For the last several years of his life, Lamarck was blind and impoverished.
The definitive (English language) treatment of Lamarck’s scholarship can be found in The Spirit of System: Lamarck and Evolutionary Biology by Richard W. Burkhardt, Jr. (1977 and 1995).
An extensive website for information on the works and heritage of Lamarck can be found by clicking here.
James Hutton (1726-1797)
James Hutton is best known for his important contributions to the science of geology (uniformitarianism and the great age of the earth). However, Hutton was also the first person to propose a mechanism of natural selection to account for evolutionary change over time. In his book, Investigation of the Principles of Knowledge (1794), he lays out a clear argument for a process of transmutation by natural selection, and does so through analogy with the process of artificial selection (click here to link to the relevant passages). Hutton argues that members of species vary, and that when the environment changes over time, those individuals best adapted to the new environment will survive, while those poorly adapted will perish. Thus, a process of natural selection (Hutton did not use this term) inevitably leads to change within species over time.
Etienne Geoffroy St. Hilaire (1772-1844)
William Herbert (1778-1847)
William Herbert was an accomplished scholar, poet, plant hybridizer, and Church of England clergyman who eventually rose to the position of Dean of Manchester. Charles Darwin referred to Herbert as “the third greatest Hybridiser who ever lived.” And indeed, Herbert’s evolutionary view of the world was largely informed by his plant-breeding work.
In 1822, Herbert wrote a seminal paper on the evolution of the constituent species of plant genera from a common ancestor. This paper, “On the Production of Hybrid Vegetables” is extraordinarily forward-thinking and uses the results of hybridization experiments between species as a basis for creating an essentially biosystematic concept of plant relationships. Herbert inferred that the ability of two species to hybridize must be evidence of evolutionary relationship and descent from a common ancestor. He wrote “If it is meant only that fertile offspring may be supposed to intimate, that the two parent plants have branched out from one common stock since the creation of the world, I am fully disposed to admit the truth of that position; but I should go much further, considering that many species…have also descended from one original…” (16). He would go on to define a genus as “all the species which have peculiar affinities, distinguishing them from all others; and which, I think, render it probable that they have branched, since the creation of the world, from one original” (21).
While Herbert was clearly an evolutionist who believed in descent with modification, he was also a creationist who thought that “in the early periods of the world, there existed
only the distinct genera of plants, or heads of families… The lapse of centuries and diversity of soil and climate have probably wrought the most wide and permanent distinctions between vegetables, that have originated from a common stock“ (16, 1822). These ideas would be reiterated in his seminal book Amaryllidaceae (1837), as well as in two papers – “Local Habitation and Wants of Plants” and “On Hybridization amongst Vegetables” published in the Journal of the Horticultural Society of London in 1846 and 1847, respectively.” Darwin wrote to Joseph Hooker about these two papers of Herbert “whose writing I always like.” Herbert’s final thoughts on evolution, and his frustration with biblical literalists, appear in a poem (with an extensive footnote) in 1846 entitled “The Christian,” where Herbert maintained his ultimately hybrid view of the roots of biodiveristy:
[I]n the six great days or periods God created all that is, but not all the precise forms that are now visible. He created the material globe, vegetables, fish, reptiles, insects, birds, quadrupeds, and man; but we have no information as to the manner in which he arranged that such creations should be diversified, as to suit the gradually improving qualities of the world they were to inhabit. He may have impressed upon them a principle of change and development, by which it was pre-ordained that their posterity should become ultimately as different as the from becomes in a short space of time from the tadpole, or the butterfly from the caterpillar…
Herbert’s masterful book on Amaryllidaceae influenced Charles Darwin’s research into evolution in the botanical world. References to Amaryllidaceae are found in Darwin’s Notebook E, and Herbert’s evolutionary ideas are noted in the “Historical Sketch” of the third and subsequent editions of On the Origin of Species. There, Darwin wrote of Herbert: “The Dean believes that single species of each genus were created in an originally highly plastic condition, and that these have produced, chiefly by intercrossing, but likewise by variation, all our existing species.” Amaryllidaceae was by no means Darwin’s only point of contact with Herbert’s work. There was, in fact, a history of communication between Darwin and the Dean of Manchester. In April 1839, Darwin sent a list of questions to Herbert, through their mutual acquaintance and Darwin’s former Cambridge professor, John Stevens Henslow. Most notably, Darwin inquires as to whether Herbert’s crossing experiments led him to notice “any relation between a facility in varying…and a facility in giving hybrids, and especially fertile hybrids.” (Herbert responded to this question in the negative, citing the example of crocuses, which he found difficult to hybridize despite the many varieties known to exist.)
Perhaps is it fitting that one of the last, if not the very last, person to see William Herbert before he died (suddenly), was Charles Darwin himself. As Darwin wrote to Joseph Hooker on June 2, 1847, “I saw the poor old Dean of Manchester on Friday & he received me very kindly: he looked dreadfully ill & about an hour afterward died! I am most sincerely sorry for it.”
Samuel Haldeman (1812-1880)
Samuel Haldeman was one of the only Americans, prior to 1859, to write about the process of evolution. Over his lifetime, he engaged in an extraordinarily diverse set of scholarly activities ranging from malacology to chess and philology. Early in his career, he performed geological survey work in New Jersey and Pennsylvania. Haldeman attended Dickinson College and eventually held academic positions at the Franklin Institute of Philadelphia, Delaware College, and the University of Pennsylvania. He wrote the first dictionary and analysis of the Pennsylvania Dutch language. In the mid 1840s, he published a paper, “Enumeration of the recent Freshwater Mollusca which Are Common to North American and Europe; With Observations on Species and their Distribution” in which he discussed the process of transmutation. Darwin read this paper and discussed it in correspondence with Charles Lyell (click here for letter) and Joseph Hooker (click here for letter).