Charles Darwin did not know much about medicine (and neither did any of his contemporaries) but he took plenty of it. Soon after his return from the voyage on HMS Beagle he was struck down by a mysterious illness. Much energy has been expended on deciding what it might have been—a supposed conflict between Christian belief and rationalism, a parasite picked up in Brazil, or even, some say, the obsessive swallowing of air. The great man’s later years were marked by a series of bizarre attempts to remedy his feeble state (even if he did write that illness, “though it has annihilated several years of my life, has saved me from the distractions of society and its amusements”).
In the 1966 film Fantastic Voyage, miniaturised doctors are injected into a scientist’s body, on a last-ditch mission to save his life and the vital scientific breakthrough that would perish with him. From their diminutive submarine, the human body—so familiar to the elite team—becomes a revelation. The commonplace becomes the unknown, the strange, a source of wonder. As one crew member remarks: “We’re going to see things no one has ever seen before.”
We can easily understand why Darwin’s On the Origin of Species by Means of Natural Selection has been so influential: it consists of a sustained, strongly argued case with enough vivid examples to convince educated readers without overwhelming them with too much technical detail. Ever since his voyage on HMS Beagle in 1831, Darwin had been reflecting on the issues and accumulating data, and the idea of natural selection as the great clue to nature had long been in his mind. But The Origin of Species was not published until 1859.
Charles Darwin found little use for art. In his introduction to The Expression of the Emotions in Men and Animals, he recorded his disappointment. “I had hoped to derive much aid from the great masters in painting and sculpture, who are such close observers. Accordingly I have looked at photographs and engravings of many well-known works; but, with a few exceptions, have not thus profited.” And it may seem that artists have returned the compliment, finding little use for Darwin.
The celebrations for the bicentennial of Darwin’s birth will be grand for good reason. Darwin’s discoveries are generating new insights faster than ever, especially in medicine and public health. Second editions of important books on evolution and medicine have just appeared, major conferences are taking place worldwide, and scores of universities now offer courses on evolutionary medicine. However, physicians are being left out. Most never take an evolutionary biology course, and no medical school teaches evolutionary biology as a basic medical science.
Throughout its research history, the fruit fly Drosophila melanogaster has provided insights into the nature and role of mutation and genetic variation in evolution. More recently, it has also contributed to our understanding of molecular and cellular mechanisms. Altogether, it would not be an exaggeration to say that the fruit fly has been the darwinians’ workhorse.
Socioeconomic inequalities in health are complex and challenging problems. Although the poorer health and shorter life expectancies of people in lower socioeconomic groups than of those in more privileged classes are not surprising, elucidation of the reasons for these inequalities has proven difficult. Some researchers have focused on the role of unhealthy behaviours, others have emphasised the importance of psychosocial stress, and yet others have called attention to material problems such as diet, housing, and occupational exposure to toxins.
In a collection of Darwin material lies a privately printed document from 1888 on Charles Darwin’s ancestors, a painstaking inquiry drawing heavily on records of legal documents such as wills and property transfers. Confidence in information on the Darwin forebears arrives in the 17th century with a succession of William Darwins, one of whom married the daughter of a lawyer called Erasmus Earle, whose forename was to have several entries in the Darwin dynasty. The wife of this William’s son was heiress to Robert Waring, two other dynastic names.
Think Darwin, think finches. That’s the way it is. Charles Darwin left Cambridge University, set sail on HMS Beagle, headed straight for the Galapagos archipelago in the Pacific, and while pondering the improbable life residing there he saw the little brown and black birds with their differently shaped bills and “Eureka!”—the theory of evolution hatched right there. Darwin winged it home, wrote On the Origin of Species, and the rest is history. Had it not been for those 14 species of unprepossessing birds, humankind would still be languishing in some intellectual dark age.
“Until Mr. Darwin can overcome the strong evidence that undoubtedly exists adverse to his views, he cannot hope to carry conviction to the minds of those even disposed to accept the bold flights of a speculative mind. To those, on the other hand, who would require testimony of the strongest possible kind to substantiate views so utterly opposed to their conception of man’s mental and moral attributes, and the responsibilities which the possession of them necessarily entails, Mr. Darwin’s array of facts must appear quite inadequate, and his reasoning from them inconclusive, if not altogether false.
Charles Darwin is widely venerated as the man who discovered evolution. But did he? When Darwin wrote, the theory that complex life developed from simple life, by material transformation, was already old: it had been advocated by, among others, his paternal grandfather Erasmus. Did Darwin, then, discover the mechanism of natural selection? No. His achievement was to propose that life—including human life—developed, and could be explained, solely by mechanistic forces, primarily natural and sexual selection.
Unlike most of today’s scientists, Charles Darwin’s fame is based on books. In a series of extraordinary volumes—The Voyage of the Beagle (1839), On the Origin of Species (1859), The Descent of Man (1871), and The Expression of the Emotions in Men and Animals (1872)—Darwin reported his observations, explained his ideas, and amplified his thinking in ways well beyond the contemporary expectations of science. His books were neither summaries nor simplifications: they were the core of his originality.
Over the past 5 years, the technologies available to geneticists have advanced in leaps and bounds. It is now possible to analyse more than 500 000 polymorphisms in an individual on a DNA chip at reasonably low cost. These polymorphisms have been judiciously chosen, on the basis of human haplotype structure, to allow high-resolution surveys aimed at identifying any common genetic variability that predisposes to disease. Although the major driving force for the design of these genetic platforms has been the identification of disease risk loci, a task for which they have been extremely successful, their use is also having profound effects on other areas of biology and especially on population genetics.
We are not our genes. Genes are just part of the story. We cannot fully blame our genome for our behaviour and susceptibility to disease. In Lehninger’s classic textbook for students of medicine and biology we can find a more accurate definition: we are our proteins (and our carbohydrates, fat, and so on). This more precise definition relates to the central dogma of molecular biology, that our proteins are generated from our DNA via an RNA intermediate state. These RNA molecules are translated into proteins.
“Owing to this struggle for life, any variation, however slight and from whatever cause proceeding, if it be in any degree profitable to an individual of any species, in its infinitely complex relations to other organic beings and to external nature, will tend to the preservation of that individual, and will generally be inherited by its offspring.”Charles Darwin
21st century eugenics?