The Selfish Gene , 50 years on — it’s time for an update

I first read The Selfish Gene in the 1980s, as a graduate student in neurobiology and animal behaviour. I admired the clarity with which biologist Richard Dawkins distilled mid-twentieth-century work in evolutionary biology.

The idea at the core of the book, published in 1976, was thrillingly simple: that a living organism is just a gene’s way of making more organisms that can carry the gene down the generations.

Dawkins’s paradox: dissecting the body’s battle to keep selfish genes in check

Back then, The Selfish Gene seemed pretty harmless. Dawkins’s ideas tracked with mainstream sociobiology. It was a popular book that covered exactly the sort of ideas that my lecturers were already teaching.

Re-reading it now, with decades of scholarship in the history of biology under my belt, it seems less benign. The determinism baked into the “gene’s-eye view” in the book troubles me, as does the passivity of the organism in Dawkins’s telling — a “vehicle”, a mere “replicator”. The implication: that traits such as aggression are hard-wired into people. Fortunately, over the past couple of decades, new tools, fresh models and scholars in many disciplines have begun to embrace the complex reality of biology. Readers in search of an understanding of life on Earth today would do better to reach for books that take a broader view.

Gene-centric views

The Selfish Gene was the apotheosis of the ‘modern evolutionary synthesis’. That theory uses mathematics to quantify species evolution at the population level, through changes in the frequency of different versions of genes, known as alleles, across time and space.

Dawkins wrote in The Selfish Gene that the gene’s-eye view was “implicit” in the 1930s writings of modern-synthesis pioneer (and eugenicist) Ronald Fisher and his contemporaries, but was made “explicit” by evolutionary biologists George Williams and William Hamilton, in the 1960s. “For me,” he wrote, “their insight had a visionary quality. But I found their expressions of it too laconic, not full-throated enough.” The Selfish Gene, then, takes the ideas to their extreme.

Richard Dawkins book of the dead is haunted by ghosts of past works

The modern synthesis blends two branches of evolutionary biology and genetics: neo-Darwinian evolution and Mendelian genetics. Neo-Darwinian evolution was established in the 1890s by biologist August Weismann in his book Die Keimplasma (The Germ Plasm). The book builds off On the Origin of Species, in which Charles Darwin outlines a central tenet — organisms evolve over many generations through an internal process called natural selection. This is the Darwinism of the first edition of On the Origin of Species, published in 1859. Yet over five successive editions, published between then and 1872, Darwin had given increasing credence to the ‘effects of use and disuse’ — the idea, associated with naturalist Jean-Baptiste Lamarck, that characteristics acquired during an organism’s lifetime can be inherited. Darwin wrote, for example, about blind cave fish (Astyanax mexicanus). Their ancestors had eyes when they first nosed into a lightless cave. But after going unused for generations, the eyes degenerated, and the change gradually became heritable.

Darwin saw no reason that his theories couldn’t accommodate such phenomena. He didn’t speculate on mechanisms. Today, an evolutionary biologist might argue that any animal that put less energy than its neighbours into making a complex but useless structure, such as an unused eye, would have surplus energy to devote to, say, bigger gonads or defending its territory, and thus would gain a survival advantage. To Weismann, however, incorporating use and disuse into Darwinism was a dangerous move towards teleology, and risked ceding biological change to bishops and mystics. He proposed that only the germ plasm (the material carried in sperm and egg cells) was passed from parents to offspring. Nothing outside could affect what was transmitted.

The second field that makes up the modern synthesis, Mendelian genetics, was invented not by Gregor Mendel, the eighteenth-century monk after whom the field is named, but by naturalist William Bateson, in his strange and brilliant 1902 book, Mendel’s Principles of Heredity: A Defence. Mendel ran experiments crossing peas, and in 1866 published a paper describing rules that governed how traits were passed down — how many offspring of a green and yellow pea cross would be green and how many yellow, for instance. We now know that only some traits, controlled by single genes, follow the simplistic patterns he observed.

The conservative Mendel claimed only to have found a law “valid for Pisum” (the pea genus); Bateson claimed that all heredity followed Mendel’s laws. Bateson’s book was ‘a defence’ against the theories of his rival and erstwhile best friend, Walter Weldon, who argued that such neat, simple laws do not describe how nature works. Weldon pointed out that traits such as height vary continuously, in a bell-shaped, normal distribution. He argued that such traits result from many factors, both hereditary and environmental.

In the end, as historian Gregory Radick has argued, Mendelism became the universally accepted form of heredity more for practical reasons than because it captured an essential truth. It’s easy to teach and methodologically simple.

The new biology

Both components of the modern synthesis focus on the gene as the sole determinant of heredity. Both halves reached essentially universal acceptance well before Dawkins came along — the spit and swagger of the field’s proponents keeping challenges and alternatives at bay.

To a historian, this universal acceptance sounds close to ideology. Fortunately, since The Selfish Gene was published, scientists’ understanding of the basic mechanisms that drive evolution has changed drastically.