In the shadow of the Origin

Everyone knows that 1859 was the year in which Charles Darwin's On the Origin of Species by Means of Natural Selection was published, but there was a significant event in September of that same year that is often overlooked. It involved the new understanding that humans and extinct mammals (like sabercats and mammoths) had lived alongside one another in ancient Europe. This may not seem like a particularly controversial point now (who today could imagine "cave men" without mammoths and woolly rhinoceros plodding about the landscape?) but during the first half of the 19th century it was certainly a contentious subject.

Part of the rejection of humans among the mammoths had to do with religious sentiment; the appearance of humans (by secondary law of nature or divine fiat) was thought to mark the beginning of a brand new era in earth's history. The monsters of previous eras had been wiped out and the world prepared for its "masters." This was reinforced by the view that the time just before our arrival was brutal. How could the first humans have survived alongside cave bears, saber-toothed cats, giant hyenas, and other dangerous beasts when mammalian predators in India and Asia were rumored to decimate entire villages in the modern world?

During the late 18th and early 19th centuries some amateur naturalists claimed they had found evidence of humans more ancient than any previously known, but the bones and stone tools were rarely accompanied by well-documented evidence. Authorities on geology and archaeology (rightly or wrongly) would rather ascribe them to ancient Celts or Romans than some ancient and unknown tribe. The turning point came in 1858 with the scientific excavation of Brixham cave in England. This site provided the first concrete and well-documented evidence that humans had lived at the time hyenas, hippopotamus, and elephants roamed England.

Even then, it took months of debate and further discoveries in northern France (particularly in the Somme Valley) for this idea to be confirmed. Some French naturalists like M. Boucher de Perthes had for years tried to push back the antiquity of humanity, but it was not until 1859 that British naturalists were fully satisfied that there was no distinct boundary separating the age of humans from the "Age of Mammals." The primary evidence for this were stone tools, and while the physical remains of the toolmakers remained elusive Charles Lyell was confident enough that the scientific consensus had changed to publicly announce the contemporaneity of the tool-makers and extinct mammals before the British Association for the Advancement of Science in September of 1859. In his introductory presidential address to the annual meeting Lyell stated;

No subject has lately excited more curiosity and general interest among geologists and the public than the question of the antiquity of the human race ; whether or no we have sufficient evidence to prove the former co-existence of man with certain extinct mammalia, in caves or in the superficial deposits commonly called drift or "diluvium." For the last quarter of a century, the occasional occurrence, in various parts of Europe, of the bones of man or the works of his hands, in cave- breccias and stalactites associated with the remains of the extinct hyaena, bear, elephant, or rhinoceros, has given rise to a suspicion that the date or man must be carried further back than we had heretofore imagined. On the other hand, extreme reluctance was naturally felt on the part of scientific reasoners to admit the validity of such evidence, seeing that so many caves have been inhabited by a succession of tenants, and have been selected by man, as a place not only of domicile, but of sepulture, while some caves have also served as the channels through which the waters of flooded rivers have flowed, so that the remains of living beings which have peopled the district at more than one era may have subsequently been mingled in such caverns and confounded together in one and the same deposit. The facts, however, recently brought to light during the systematic investigation, as reported on by Falconer, of the Brixham Cave, must, I think, have prepared you to admit that scepticism in regard to the cave-evidence in favour of the antiquity of man had previously been pushed to an extreme. To escape from what I now consider was a legitimate deduction from the facts already accumulated, we were obliged to resort to hypotheses requiring great changes in the relative levels and drainage of valleys, and, in short, the whole physical geography of the respective regions where the caves are situated--changes that would alone imply a remote antiquity for the human fossil remains, and make it probable that man was old enough to have coexisted, at least, with the Siberian mammoth.

This view held startling implications. Although some involved in the discoveries, like Joseph Prestwich, initially sidestepped controversy in stating that they did not want to make humans more ancient any more than they wanted to make mammoths more recent, Lyell understood how the finds related to a book due out in November the same year. The tools found in the cave sites were not only important to determining the age of humanity, but to the very origin of it. If humans were older than previously thought and there was no reason for geology to be the handmaiden of theological views, might it be possible that humans had not been divinely created but brought into being by the operation of some kind of natural law? Given that Lyell was among Charles Darwin's most valued friends he certainly knew that On the Origin of Species by Means of Natural Selection would soon be released, and at the close of his address he said;

Among the problems of high theoretical interest which the recent progress of Geology and Natural History has brought into notice, no one is more prominent, and at the same time more obscure, than that relating to the origin of species. On this difficult and mysterious subject a work will very shortly appear, by Mr. Charles Darwin, the result of twenty years of observation and experiments in Zoology, Botany, and Geology, by which, he has been led to the conclusion, that those powers of nature which give rise to races and permanent varieties in animals and plants, are the same as those which, in much longer periods, produce species, and, in a still longer series of ages, give rise to differences of generic rank. He appears to me to have succeeded, by his investigations and reasonings, in throwing a flood of light on many classes of phenomena connected with the affinities, geographical distribution, and geological succession of organic beings, for which no other hypothesis has been able, or has even attempted, to account.

This might have seemed like an uncomfortable fit in a speech about archaeology, and Lyell's mention of Darwin's work is notable in that he does not draw a bold connection between it and the main subject of the address. That association is left for the listener to make. Instead Lyell closes with the reminder that the fossil record is not a perfect transcript of the history of the earth; much is missing and there is surely much left to be found. Indeed, new discoveries were shifting comfortable geological boundaries: humans lived among mammoths and "highly organized" reptilian creatures from deposits previously considered to be of Devonian age were causing what was previously known to be reconsidered. Perhaps Lyell was not fully comfortable in accepting Darwin's theory, but he clearly saw that it held powerful implications and could not be ignored.

Lyell, of course, included a discussion of the Brixham cave in his later Antiquity of Man, but what did Darwin think of all this? The finds at Brixham did not feature in On the Origin of Species (he had to establish that his theory worked at all before he could fully apply it to humans, which was the biggest worry of his intellectual opponents) but his letters reveal that he was interested in the cave sites. In an 1858 letter to Joseph Hooker he wrote "I had a note from Falconer not long ago: he seems to have established a grand point, viz than man existed in England before the Rein-Deer & therefore before, I presume, the close of glacial Epoch."

Hugh Falconer, one of the naturalists central to the exploration of the Brixham site, wrote to Darwin the next year about the influence of what he had found. Lyell, in particular, was a quick and powerful convert to the idea that humans had lived alongside extinct mammals, and of this Falconer wrote;

Lyell has forgotten all his prudence and thrown himself head long into the bosom of two heresies--the transmutation of species, and glacial homo.You are answerable for the one--and I have had a little to do in starting the [scent] of the other.

Darwin knew that Falconer was only half-joking about the "heresy" he had promulgated. Darwin wrote Falconer a tongue-in-cheek reply which partly read;

... [Lyell] told me that you were very antagonistic to my views on species. I well knew this would be the case. I must freely confess the difficulties and objections are terrific; but I cannot believe that a false theory would explain, as it seems to me it does explain, so many classes of facts. Do you ever see Wollaston; He and You would agree nicely about my Book, --ill-luck to both of you. If you have anything at all pleasant for me to hear do write; and if all that you can say is very unpleasant, it will do you good to expectorate. And it is well known that you are very fond of writing letters. Farewell my good old friend and enemy.

Yours very sincerely | Charles Darwin

Darwin's curiosity about the Brixham tools does not appear to have extended beyond his correspondence, however. Of greater concern to geologists was where the bones of the toolmakers might be hiding. This was confounded by the fact that the skeletons of fossil humans (like the first Neanderthal bones) were often said to be pathological individuals, recent burials, or almost anything other than ancient humans. The old age of humanity had been shown but since paleoanthropology was just being born at the time Darwin was writing there was little support it could throw his theoretical ruminations.

A scan of the popular literature of the time also suggests that while there was some curiosity about the discoveries at Brixham and the Somme Valley they did not stir the same sort of attention that Darwin's theory did. Why should this be? Perhaps it was because explanations of the geology involved in the discoveries required too much background. It was simply easier to reprint papers, summaries, and reviews (which was done, particularly Lyell's 1859 speech) for readers with an interest in geology and simply state that our species was older than previously thought.

It could also be that this notion was not nearly as threatening as that of evolution. It did not directly conflict with Scripture (particularly a liberal reading of it) and perhaps the public saw little reason to reject it for this reason. It is also likely that the hubbub over Darwin's work and debates over higher criticism of the Bible overshadowed the discoveries. Evolutionary ideas cut much more deeply into cherished sentiments than the idea that our species was a little older than previously thought. It remained a subject of debate among geologists, archaeologists, and other naturalists, though, and it is certainly a debate worth more attention than it has often been given.