Early Responses to Darwin

From History of Evolution

Early Responses to Darwin

This section depends heavily on Janet Brown's magnificent biography of Darwin and on Edward J. Larson's Shriver Lectures at Stetson University in January 2006, collected as The Creation-Evolution Debate: Historical Perspectives.

Contents 1 Introduction 2 Building a Network of Support 3 Darwin's Four Horsemen 3.1 Thomas Henry Huxley 3.2 Joseph D. Hooker 3.3 Charles Lyell 3.4 Asa Gray in the U.S. 4 Sources of Opposition 4.1 Human Exceptionalism 4.2 Scientific Opposition 4.3 Opposition to Natural Selection 4.4 The Role of Chance

Introduction

Darwin's Origin of Species entered an intellectual world that was partly primed to accept it and partly primed to reject it. As reviewed in the preceding essays there had been foreshadowings of transmutation before Darwin, notably in Lamarck's work and in his grandfather Erasmus Darwin's Zoonomia, Charles Darwin being fully aware of both, and considerable resistance to the notion as well. The enormously popular 1844 publication of Chambers' anonymously published Vestiges of the Natural History of Creation had aroused considerable criticism from both scientists (including Darwin) and ecclesiastical authorities. Vestiges went through multiple editions in the years preceding Origin, but it offered neither a causal mechanism for change nor an accurate picture of then-current geological and biological knowledge. Knowing that Vestiges had roused a good deal of opposition, Darwin acted to distance his work from it, remarking early in Origin that

The author of the 'Vestiges of Creation' would, I presume, say that, after a certain unknown number of generations, some bird had given birth to a woodpecker, and some plant to the misseltoe, and that these had been produced perfect as we now see them; but this assumption seems to me to be no explanation, for it leaves the case of the coadaptations of organic beings to each other and to their physical conditions of life, untouched and unexplained. (pp 3-4)

Darwin thus distanced his Origin from Vestiges. He offered a mechanism, natural selection, to account for the phenomena. Nevertheless, it was that mechanism that he knew would rouse opposition. He was therefore prepared to defend his position after publication.

It was the fact that Darwin substituted a mechanical process, the algorithm of natural selection operating on chance variations, that was the source of much of the opposition to his proposal. In place of a world governed by a (presumably) benevolent deity, Darwin hypothesized a purely natural process to explain the diversity of life on earth.

Building a Network of Support

Darwin had spent the years between the beginning of his work on the species question following the voyage of the Beagle and the publication of Origin building a network of correspondents and supporters. In spite of his relative isolation in Downe House outside London he was at the center of a vast communication network of naturalists and others carried on via the post. While not as quick as email, the British postal service had multiple delliveries per day, and correspondence with other naturalists in Great Britain was easy and fast. Darwin could send a query to Hooker at Kew Garden and count on receiving an answer within a day or two.

In the months and years following publication of Origin Darwin used his network to the fullest, urging his supporters on, cajoling the undecided, clarifying his views to potentially receptive critics, arguing with (and sometimes blasting in print) his opponents, and complaining to his friends about uncharitable or mistaken reviews of his book. In turn his correspondents kept him apprised of both formal and informal critiques and support, and kept him abreast of the gossip in scientific circles in London.

Darwin's Four Horsemen

Four men formed the core of his inner circle of friends and confidants: the geologist Charles Lyell, the botanist Joseph D. Hooker, the comparative anatomist Thomas H. Huxley, all in Great Britain, and the botanist and naturalist Asa Gray in the United States. Those four men were influential in scientific circles and in varying degrees accepted Darwin's views on transmutation, common descent, and natural selection.

Thomas Henry Huxley

Huxley, called "Darwin's Bulldog," was a fine comparative anatomist who (among other things) suggested that birds descended from small dinosaurs, a conclusion now pretty firmly established in paleontology. Huxley was also very interested in public education and strongly supported the Working Men's Institution (WMI) where for a small fee ordinary people could attend lectures by experts in various fields. Huxley's own WMI lectures on Darwinian evolution are remarkably clear. Huxley also coined the term "agnostic" to characterize his (lack of) religious belief, a term Darwin late in life tentatively adopted to describe himself. Huxley represents the conflict relationship between science and religion of Phil Dowe (see below).

Joseph D. Hooker

Hooker was perhaps Darwin's best friend. Aside from their scientific alliance, they had several things in common, notably voyages as naturalists aboard British Navy survey ships (Hooker as assistant surgeon and naturalist) and the loss of a beloved child (Darwin's daughter Annie at age 10 and Hooker's daughter Marie at age 6). Hooker was the son of the director of the Royal Gardens at Kew, and succeeded his father as director. That gave him (and therefore Darwin) direct access to the tens of thousands of botanical specimens being shipped to Great Britain from the growing British Empire. The number and diversity of biological specimens returned to Great Britain is amazing. For example, in his 8-year sojourn in the Malay Peninsula, Wallace collected some 125,000 specimens! This was an enormous pool of potential data for testing hypotheses in biology, akin to the vast pool of genetic data being made available today in the various bioinformatics databases.

Charles Lyell

In contrast to Hooker, Gray, and Huxley, Lyell was, like Darwin, a 'gentleman scientist.' He had sufficient private money to have the leisure to pursue geology without the necessity of making a living at it. Lyell's Principles of Geology accompanied Darwin on the voyage of the Beagle and strongly influenced his thinking on geology and more generally on incremental change through time. While Lyell didn't completely accept Darwin's views in Origin, he strongly supported Darwin's right to publish and to be heard, and supported Darwin's view of transmutation -- change in species through time -- though he was reluctant to accept the struggle for existence and natural selection as the driver of biological change. Lyell's The Geological Evidences of the Antiquity of Man, published in 1863, described the geological and paleontological evidence for humans on earth well before young earth theists allowed. In that book Lyell also commented critically on evolution by natural selection, not going as far as Darwin wished but as far as Lyell's own views permitted. In particular, Lyell rejected the hypothesis that the cognitive and 'moral' characteristics of humans have evolved from "lower" animals, suggesting instead a saltational view of the emergence of human intelligence:

We may also demur to the assumption that the hypothesis of variation and natural selection obliges us to assume that there was an absolutely insensible passage from the highest intelligence of the inferior animals to the improvable reason of Man. The birth of an individual of transcendent genius, of parents who have never displayed any intellectual capacity above the average standard of their age or race, is a phenomenon not to be lost sight of, when we are conjecturing whether the successive steps in advance by which a progressive scheme has been developed may not admit of occasional strides, constituting breaks in an otherwise continuous series of psychical changes. (Gutenberg Project version unpaginated)

A few paragraphs later, quoting Asa Gray, Lyell also left open the possibility of front-loading or direction by a deity:

The whole course of nature may be the material embodiment of a preconcerted arrangement; and if the succession of events be explained by transmutation, the perpetual adaptation of the organic world to new conditions leaves the argument in favour of design, and therefore of a designer, as valid as ever; "for to do any work by an instrument must require, and therefore presuppose, the exertion rather of more than of less power, than to do it directly."* (* Asa Gray, "Natural Selection not inconsistent with Natural Theology" Trubner & Co. London 1861 page 55.) (unpaginated)

Asa Gray in the U.S.

Asa Gray was a devout Presbyterian and an eminent botanist in the United States. He and Darwin corresponded for decades, and Gray was Darwin's principal sounding board and critic for some of the theological implications of evolution by natural selection. Gray argued for a sort of theistic evolution in which there was a direction to evolution. His views are fairly represented in his Natural Selection Not Inconsistent With Natural Theology. Gray was a scientific and academic opponent of Louis Agassiz. From his post at Harvard Agassiz dominated American biological science in the mid-19th century and strongly defended Cuvier's catastrophism position. Gray, also a distinguished professor at Harvard, defended Darwin's views in a variety of reviews and publications, many collected in his Darwiniana. His characterization of the differences between Agassiz and Darwin are outlined in the first essay in that collection, a review of On the Origin of Species published in March, 1860. Gray represents the Harmony style of relationship between science and religion of Phil Dowe.

Sources of Opposition

As with Vestiges, opposition to Origin came from both scientists and ecclesiastics. However, the scientific opposition was mainly centered in the older generation, among them some of Darwin's teachers, and almost always displayed theological overtones as well as scientific objections. For example, Adam Sedgwick, with whom Darwin studied geology during a summer of fieldwork while he was at Cambridge, rejected the central argument of Origin, that life forms on earth are related by common ancestry. Sedgwick was an old-earth supporter but a catastrophist, in contrast to Lyell's uniformitarianism. He was of the generation of geologists who illuminated deep time, but he rejected the biological theory of evolution, opting for what amounts to progressive creationism with new creations filling in biota after catastrophic extinctions. In particular he rejected what he saw as the moral implications of mechanistic Darwinian evolution. Recall that like almost all Cambridge dons of his era, Sedgwick was in holy orders in the Anglican Church.

Human Exceptionalism

It was rapidly realized that Darwinian evolution, if true, has implications for the exceptionality of human beings. The religious views of the day, whether Church of England, Roman Catholic, or the various Protestant denominations that were growing in Great Britain and the U.S., all put a high premium on the assumption of human exceptionalism. This is the view that there is a wide and uncrossable gap between humans and the rest of life on earth, and that the world -- indeed, the whole universe -- was created specifically and intentionally for the human species. Theologically it is the "man created in God's image" view -- humans were created in God's image, but not so the rest of life. Though Darwin made only one short mention of human evolution in Origin, the implications of his theory were clear: Humans are descended from an ancestor from which other apes -- chimpanzees, gorillas, etc. -- also descended. They are our cousins. All Darwin said about human evolution in Origin was

In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history. (p. 488)

Huxley, however, elaborated on the implications for humans (also available here), writing in 1861:

Thus, whatever system of organs be studied, the comparison of their modifications in the ape series leads to one and the same result–that the structural differences which separate Man from the Gorilla and the Chimpanzee are not so great as those which separate the Gorilla from the lower apes. (p. 144)

and

But if Man be separated by no greater structural barrier from the brutes than they are from one another–then it seems to follow that if any process of physical causation can be discovered by which the genera and families of ordinary animals have been produced, that process of causation is amply sufficient to account for the origin of Man. In other words, if it could be shown that the Marmosets, for example, have arisen by gradual modification of the ordinary Platyrhini, or that both Marmosets and Platyrhini are modified ramifications of a primitive stock–then, there would be no rational ground for doubting that man might have originated, in the one case, by the gradual modification of a man-like ape; or, in the other case, as a ramification of the same primitive stock as those apes. (pp 146-147)

Huxley went much further than Darwin was prepared to go, particularly in his antipathy toward organized religion. In 1860 Huxley wrote:

Who shall number the patient and earnest seekers after truth, from the days of Galileo until now, whose lives have been embittered and their good name blasted by the mistaken zeal of Bibliolaters? Who shall count the host of weaker men whose sense of truth has been destroyed in the effort to harmonise impossibilities--whose life has been wasted in the attempt to force the generous new wine of Science into the old bottles of Judaism, compelled by the outcry of the same strong party?

It is true that if philosophers have suffered, their cause has been amply avenged. Extinguished theologians lie about the cradle of every science as the strangled snakes beside that of Hercules; and history records that whenever science and orthodoxy have been fairly opposed, the latter has been forced to retire from the lists, bleeding and crushed if not annihilated; scotched, if not slain.

That implication drove everything from Bishop Wilberforce's (almost certainly apocryphal) inquiry of Huxley as to whether it was through his grandmother or grandfather that he was descended from apes, to the remark a Christian creationist made to me at a local school board meeting in the summer of 2008 that "I'm a Christian, and I don't believe I came from an ape."

The theological implication seemed clear: If humans are descended from other species then Adam and Eve as the first human pair had not existed. If Adam and Eve didn't exist then the Fall, with its accompanying Original Sin, didn't occur, and as a consequence the redemptive message of the birth, ministry, death, and resurrection of Jesus Christ is superfluous. If there is no Fall, there is no need for redemption. That undercuts the very basis of Christianity, at least if the Fall and Resurrection are taken to be literal historical events, and the religious authorities were appropriately incensed. Removal of God as the designer was unacceptable to 19th century theists (and indeed, as it is to 21st century theists). Evolution is interpreted to be tantamount to atheism. To give but one example, Charles Hodge, an influential 19th century American theologian, wrote

The conclusion of the whole matter is, that the denial of design in nature is virtually the denial of God. Mr. Darwin's theory does deny all design in nature, therefore, his theory is virtually atheistical; his theory, not he himself. He believes in a Creator. But when that Creator, millions on millions of ages ago, did something,—called matter and a living germ into existence,—and then abandoned the universe to itself to be controlled by chance and necessity, without any purpose on his part as to the result, or any intervention or guidance, then He is virtually consigned, so far as we are concerned, to non-existence. (pp. 173-4)

On the other hand, American feminist Elizabeth Cady Stanton exulted in the apparent denial of the Fall, writing in The Woman's Bible:

The real difficulty in woman's case is that the whole foundation of the Christian religion rests on her temptation and man's Fall, hence the necessity of a Redeemer and a plan for salvation. As the chief cause of this dire calamity, woman's degradation and subordination were made a necessity. If, however, we accept the Darwinian theory, that the race has been a gradual growth from the lower to a higher form of life, and that story of the fall is a myth, we can exonerate the snake, emancipate the woman, and reconstruct a more rational religion for the nineteenth century, and thus escape all the perplexities of the Jewish mythology as of no more importance than those of the Greek, Persian, and Egyptian. (p. 214)

Scientific Opposition

While much of the scientific opposition to Darwin's theory had theological overtones, nevertheless there was (variably) good scientific reasoning behind much of it. For example, Sir Richard Owen, a prominent comparative anatomist and paleontologist (and antagonist of Huxley and Hooker), argued (among other things) that there were no transitional forms and that in general Darwin's data were weak or non-existent. Moreover, Owen argued, the existence of neuter ants and bees that nonetheless play important roles in the functioning of nests and hives casts doubt on the hypothesis. Concerning fossils, Owen (anonymously citing his own work) wrote

But when Mr. Darwin, in reference to the absence of the intermediate fossil forms required by his hypothesis--and only the zootomical zoologist can approximatively appreciate their immense numbers--the countless hosts of transitional links which, on 'natural selection,' must certainly have existed at one period or another of the world's history--when Mr. Darwin exclaims what may be, or what may not be, the forms yet forthcoming out of the graveyards of strata, we would reply, that our only ground for prophesying of what may come, is by the analogy of what has come to light. We may expect, e.g., a chambered-shell from a secondary rock; but not the evidence of a creature linking on the cuttle-fish to the lump-fish. (unpaginated)

and

The last ichthyosaurus, by which the genus disappears in the chalk, is hardly distinguishable specifically from the first ichthyosaurus, which abruptly introduces that strange form of sea-lizard in the lias. The oldest Pterodactyle is as thorough and complete a one as the latest. No contrast can be more remarkable, nor, we believe, more instructive, than the abundance of evidence of the various species of ichthyosaurus throughout the marine strata of the oolite and cretaceous periods, and the utter blank in reference to any form calculated to enlighten us as to whence the ichthyosaurus came, or what it graduated into, before or after these periods. The Enaliosauria of the secondary seas were superseded by the Cetacea of the tertiary ones.

Owen also called attention to Cuvier's analysis of mummified cats and ibises brought back from Napoleon's invasion of Egypt which showed that essentially no change had occurred in the 3,000 years since they were mummified. Following Cuvier, Owen argued against transmutation, favoring instead his (and Cuvier's) theory of archetypal forms.

Others, even Darwin's closest allies, doubted one or another aspect of his theory. Huxley, for example, irritated Darwin by opposing Darwin's insistence on small incremental change, and by doubting Darwin's hypotheses concerning reproductive isolation due to inter-variety sterility leading to speciation. Asa Gray, clearly motivated by his theological biases, plumped for directed variation. He accepted the essentially mechanical operation of natural selection, but wanted to preserve a role for God in the process, and that role, he argued, was to generate the necessary beneficial variants on which natural selection could operate.

Even Alfred Russell Wallace, co-discoverer of the principle of natural selection who had a mystical/spiritualist side, parted from Darwin -- and from common descent -- with respect to humans' "higher" mental and moral capabilities. As early as 1866, just four years after his return to Great Britain after his sojourn in the Malay Peninsula, Wallace published a pamphlet called The scientific aspect of the supernatural. See here for more. Wallace also placed more emphasis on selection at the species level, as distinguished from selection of individuals in populations as Darwin had it. The popular conception of evolution as being somehow in the interest of the species -- "for the good of the species" -- is more properly a Wallaceian rather than a Darwinian thought. In contrast (usually) with Darwin, Wallace also thought that evolution was progressive, with species inevitably becoming more and more different and more complex.

Opposition to Natural Selection

The main scientific aspect of Darwin's theory that was not accepted in the last half of the 19th century was natural selection. Transmutation and common descent (at least for everything but some aspects of humans) were widely accepted within 10 years of the initial publication of Origin, but natural selection, often misinterpreted, was not. The logic of the evolutionary algorithm and the power of small incremental changes to alter lineages over vast time spans, were (and still are) very difficult to integrate into a world view that viewed time in terms of hundreds or thousands of years rather than millions and tens of millions of years. And even the time available was strongly disputed. William Thompson, later Lord Kelvin, published a series of estimates of the age of the earth and the sun that put the maximum habitable time somewhere in the neighborhood of 20 million years, and that wasn't nearly enough time for evolution to have operated as Darwin argued it did.

And natural selection's lack of a long-term goal, that it is unguided except for the regularities in the selective environment, was hard to accept for those whose prior beliefs required a teleological world.

Because Darwin did not have a satisfactory theory of inheritance, and because the general view at the time was of blending inheritance, it was difficult to see how varieties could differentiate enough to become new species. This was a component of Huxley's reservations about the whole theory. Fleeming Jenkin, a polymath engineer, argued in 1867 that variation would be swamped in large populations with blending inheritance -- that single variants ("sports" in the term of the day) could not get a foothold in a population unless the rate of occurrence of "sports" was very high, much higher than observed. Of course, that blending inheritance had to be false should have been apparent even then, since variation was not disappearing at anything close to the rate that blending inheritance implies it should. Nevertheless, Darwin was very worried about it, and argued that his pangenesis theory, spiced up with a touch of Lamarckian inheritance of acquired traits, could handle the problem. (Mayr argues that Darwin did not accept blending inheritance, but John Wilkins (personal communication) demurs, arguing that Darwin's proposal of pangenesis was an analog process and therefore implied blending inheritance.)

The Role of Chance

Opposition to Darwin's theory came from both scientists and theists over the role Darwin was interpreted to ascribe to chance in the production of variations in a population. Recall that Darwin's theory asserts that adaptive structures are due to natural selection sorting through the chance variations in a population, preserving those that aid reproductive success and discarding those that are deleterious. Theists opposed that assertion on the understandable ground that attributing events to chance eliminates God's providential action in causing those events. As noted above, Asa Gray didn't accept the view that variations are chance events, writing in Natural Selection is not Inconsistent with Natural Theology

On the other hand, if Darwin even admits--we will not say adopts--the theistic view, he may save himself much needless trouble in the endeavor to account for the absence of every sort of intermediate form. Those in the line between one species and another supposed to be derived from it he may be bound to provide; but as to "an infinite number of other varieties not intermediate, gross, rude, and purposeless, the unmeaning creations of an unconscious cause," born only to perish, which a relentless reviewer has imposed upon his theory--rightly enough upon the atheistic alternative--the theistic view rids him at once of this "scum of creation."

...

Wherefore, if we believe that the species were designed, and that natural propagation was designed, how can we say that the actual varieties of the species were not equally designed? Have we not similar grounds for inferring design in the supposed varieties of species, that we have in the case of the supposed species of a genus? When a naturalist comes to regard as three closely related species what he before took to be so many varieties of one species how has he thereby strengthened our conviction that the three forms are designed to have the differences which they actually exhibit? Wherefore so long as gradatory, orderly, and adapted forms in Nature argue design, and at least while the physical cause of variation is utterly unknown and mysterious, we should advise Mr. Darwin to assume in the philosophy of his hypothesis that variation has been led along certain beneficial lines. Streams flowing over a sloping plain by gravitation (here the counterpart of natural selection) may have worn their actual channels as they flowed; yet their particular courses may have been assigned; and where we see them forming definite and useful lines of irrigation, after a manner unaccountable on the laws of gravitation and dynamics, we should believe that the distribution was designed.

In other words, Gray suggested that the variants on which natural selection works are not random, but rather are directed. Gray is clearly arguing for a role for God in evolution, basing his argument on both the analogy of human design (the irrigation streams), and Darwin's ignorance of the causes of variation. That latter was (and to some extent still is) a central issue in evolution. And Gray was raising scientific problems -- the absence of numerous variants connecting species -- that he thought could be solved by adopting (God-) directed variation.

But Darwin didn't exactly attribute variations to "chance." In Origin he wrote

I HAVE hitherto sometimes spoken as if the variations—so common and multiform in organic beings under domestication, and in a lesser degree in those in a state of nature—had been due to chance. This, of course, is a wholly incorrect expression, but it serves to acknowledge plainly our ignorance of the cause of each particular variation. (page 131)

In other words, he used "chance" as a synonym for "we don't know what causes the variations." That's the opening that allowed Gray to insert directed variation. In fact, in Variability Under Domestication Darwin spends a whole chapter (XXII) discussing the potential causal explanations of variations, finally attributing them to variations in "the conditions of life":

Summary.—From the facts given in this chapter, we may conclude that the variability of organic beings under domestication, although so general, is not an inevitable contingent on growth and reproduction, but results from the conditions to which the parents have been exposed. Changes of any kind in the conditions of life, even extremely slight changes, often suffice to cause variability.

...

Some variations are induced by the direct action of the surrounding conditions on the whole organisation, or on certain parts alone, and other variations are induced indirectly through the reproductive system being affected in the same manner as is so common with organic beings when removed from their natural conditions. The causes which induce variability act on the mature organism, on the embryo, and, as we have good reason to believe, on both sexual elements before impregnation has been effected. (p. 270)

See also Sara Joan Miles' discussion ot the Darwin/Gray correspondence. John Wilkins has a recent post on Gray's argument suggesting that it does not necessarily entail that God is a micro-manager that oversees every single mutation that occurs, and hence that contemporary theistic evolutionists are not holding an incoherent position, contrary to critiques of them from both materialists and more fundamentalist theists. Also see Wilkin's ruminations on chance here.