Thomas Henry Huxley was one of the first adherents to Darwin's theory of evolution by natural selection, and did more than anyone else to advance its acceptance among scientists and the public alike. As is evident from the letter quoted above, Huxley was a passionate defender of Darwin's theory -- so passionate that he has been called "Darwin's Bulldog". But Huxley was not only the bulldog for Darwin's theory, but was a great biologist in his own right, who did original research in zoology and paleontology. Nor did he slavishly and uncritically swallow Darwin's theory; he criticized several aspects of it, pointing out a number of problems.
He was born on May 4, 1825, in Ealing, near London, the seventh of eight children in a family that was none too affluent. Huxley's only childhood education was two years at Ealing school, where his father taught mathematics; this ended in 1835 when the family moved to Coventry. Despite his lack of formal education, young Huxley read voraciously in science, history, and philosophy, and taught himself German. At the age of 15, Huxley began a medical apprenticeship; soon he won a scholarship to study at Charing Cross Hospital. At 21, Huxley signed on as assistant surgeon on the H.M.S. Rattlesnake, a Royal Navy frigate assigned to chart the seas around Australia and New Guinea. Huxley vividly described conditions on the ship in his diary:
I wonder if it is possible for the mind of man to conceive anything more degradingly offensive than the condition of us 150 men, shut up in this wooden box, being watered with hot water, as we are now. . . It's too hot to sleep, and my sole amusement consists in watching the cockroaches, which are in a state of intense excitement and happiness.
Despite the excited cockroaches and the poor science facilities on board, Huxley collected and studied marine invertebrates, in particular cnidarians, tunicates, and cephalopod molluscs. (He also collected a fiancée, Henrietta Heathorn, whom he met and immediately fell in love with while in port in Sydney, Australia.) When he returned to England in October 1850, he found that his research results, which he had mailed back to England from each port of call, had won him acceptance into the ranks of the English scientific establishment. Huxley soon became acquainted with scientists like the geologist Charles Lyell, the botanist Joseph Hooker, the philosopher Herbert Spencer, and the naturalist Charles Darwin. Professional positions in science were rare at the time -- most naturalists were affluent amateurs -- but Huxley managed to support himself on a stipend from the Navy and by writing popular science articles. After leaving the Navy in 1854, Huxley managed to secure a lectureship at the School of Mines in London, and sent for his fiancée. They were married in 1855.
Huxley's Scientific Thought
As the nickname "Darwin's bulldog" would suggest, Huxley was an outspoken defender and advocate for Darwin's theory of evolution by natural selection. Perhaps surprisingly, he was at first an opponent of any evolutionary change at all, believing that the living world had stayed much the same for as far back as its history could be traced, and that modern taxa would eventually be found in the oldest rocks. But he came to accept evolutionary views: his reaction to reading the Origin of Species was "How stupid of me not to have thought of that."
He is best known for his famous debate in June 1860, at the British Association meeting at Oxford. His opponent, Archbishop Samuel Wilberforce, was not-so-affectionately known as "Soapy Sam" for his renowned slipperiness in debate. Wilberforce was coached against Huxley by Richard Owen. During the debate, Archbishop Wilberforce ridiculed evolution and asked Huxley whether he was descended from an ape on his grandmother's side or his grandfather's. Accounts vary as to exactly what happened next, but according to one telling of the story, Huxley muttered "The Lord hath delivered him into my hands," and then rose to give a brilliant defense of Darwin's theory, concluding with the rejoinder, "I would rather be the offspring of two apes than be a man and afraid to face the truth." Huxley's own retelling of the tale was a little different, and quite a bit less dramatic:
If then, said I, the question is put to me would I rather have a miserable ape for a grandfather or a man highly endowed by nature and possessed of great means of influence & yet who employs these faculties & that influence for the mere purpose of introducing ridicule into a grave scientific discussion, I unhesitatingly affirm my preference for the ape.
All accounts agree that Huxley trounced Wilberforce in the debate, defending evolution as the best explanation yet advanced for species diversity.
However, Huxley did not blindly follow Darwin's theory, and critiqued it even as he was defending it. In particular, where Darwin had seen evolution and a slow, gradual, continuous process, Huxley thought that an evolving lineage might make rapid jumps, or saltations. As he wrote to Darwin just before publication of the Origin of Species, "You have loaded yourself with an unnecessary difficulty in adopting Natura non facit saltum [Nature does not make leaps] so unreservedly."
Huxley's support for natural selection is perhaps surprising when contrasted with his earlier attacks on the evolutionary theories put forth by Lamarck and Robert Chambers. Both of these theories advocated some kind of progression -- some kind of general tendency present in all organisms to evolve "upward" into more and more complex forms. Huxley would have nothing to do with such progressionist ideas, which he regarded as being more metaphysical than scientific; this mistrust of progression lay behind his initial skepticism of all evolutionary ideas. Similarly, Huxley rejected the then-popular theory of recapitulation, following Karl von Baer (whose writings Huxley had translated from the German). Huxley wrote, "the progress of a higher animal in development is not through the forms of the lower, but through forms which are common to both lower and higher. . . "
Huxley's most famous writing, published in 1863, is Evidence on Man's Place in Nature. This book, published only five years after Darwin's Origin of Species, was a comprehensive review of what was known at the time about primate and human paleontology and ethology. More than that, it was the first attempt to apply evolution explicitly to the human race. Darwin had avoided direct mention of human evolution, stating only that "light will be thrown on the origin of Man;" Huxley explicitly presented evidence for human evolution. In this, once again, he locked horns with Richard Owen, who had claimed that the human brain contained parts that were not found in apes, and that therefore humans could not be classified with the apes nor descended from them. Huxley and his colleagues showed that the brains of apes and humans were fundamentally similar in every anatomical detail.
Huxley founded a remarkable dynasty of English scientists and thinkers. His son Leonard was a noted biographer and "man of letters." Leonard's oldest son Julian was one of the authors of the evolutionary synthesis of the early 20th century; Julian's son Francis became a noted anthropologist. Another of Leonard's sons, Andrew (later Sir Andrew Huxley) was also an eminent scientist, sharing the 1963 Nobel Prize in Physiology or Medicine for his work on nerve impulses and muscle contraction. Julian's brother Aldous Huxley was a novelist, screenwriter and essayist; his best-known book is the anti-utopia Brave New World. A more distant relative, Leonard George Golden Huxley, became a prominent physicist.