Time, Love, and Memory: A Great Biologist and His Quest for the Origins of Behavior

  • Jonathan Weiner
Alfred A. Knopf: 1999. 290 pp. $27

William of Occam preached that “entities should not be multiplied beyond necessity”, but did not forget to add: “there are many things that God does with more that he could do with fewer.” The interplay between bold and cautious Occamism is the secret of successful science. This book is about a scientist who for the past six decades has navigated his way in a marvellously idiosyncratic style on the edge of Occam's razor, and swept biology, once and again, into new territories.

In the 1950s, in his adventures into the genetics of a virus, Seymour Benzer tore a window to the microcosm of the gene. In the late 1960s, toying with fruitflies in test-tubes, he altered neurobiology. Hundreds of hectic investigators at this very moment run knockout mice in watermazes, slice the brains of transgenics or compose a paper to convince the world that their mutant is the only clue to dementia. Many of them may not even have the faintest idea how it all started. Such is the fate of success: E. O. Wilson, cited by Jonathan Weiner, commented: “progress in a scientific discipline can be measured by how quickly its founders are forgotten.” Time, Love, and Memory may hence be prescribed as an anti-amnesic potion to generations of neuroscientists.

Weiner's book is about Benzer and his quest for the origins of behaviour; it is also about a fascinating chapter in the history of science that, because the investigator and his organism played it low-key, was protected from attention for far too long — including probably the attention of the jury in Stockholm.

Benzer's lab at its most intensive period was off-off-Broadway, but it is there that a dominant scientific culture was founded. Time, Love, and Memory navigates us through Benzer's career with great detail, encompassing both scientific and personal life. We learn about the early days in physics (Benzer was among the discoverers of transistor technology); about the fascination with Erwin Schrödinger's What is Life?; and about the influence of another physicist, Max Delbrück, who started modern molecular biology by focusing on the tiny viruses — bacteriophage — as atoms of inheritance.

Benzer was drafted into the reductionist revolution. After years of almost manic research, he was able to present the world with the first fine physical map of a gene. This turned him into the legendary ‘atom-breaker of biology’. Other scientists would have probably capitalized on the success past retirement well into afterlife. Not Benzer. A loner by nature (a mutant?), Benzer consistently shies away from the crowds, especially when they attempt to join him. He is a scout, not a general, an obsessive wanderer into uncharted terrain.

Indeed, for a while he drifted into the more tranquil waters of RNA research. Delbrück, who started getting reprints, was quick to react: “Please ask Seymour,” he wrote to Benzer's first wife, Dotty, “to stop writing so many papers⃛ If he must continue, tell him to do what Ernst Mayer asked his mother to do in her long daily letters, namely, underline what is important.” Benzer learned a lesson that should be included in the curriculum of every biology programme: ‘beware of falling into the biochemical drain’.

He traded phage for fruitflies. The rest is history. In 1967 he published his first neurogenetic paper: “Behavioural mutants of Drosophila isolated by countercurrent distribution”. It is the epitome of an ingeniously simple approach to an extremely complex problem. The basic idea behind it all is: treat flies as atoms of behaviour. Induce single gene mutations. Devise a simple behavioural assay. Isolate mutants that flunk in the test. You now have an entry point into the dissection of behaviour.

Over the years, hundreds of mutants were identified. Weiner concentrates on three classes: clock mutants, which disrupt biological rhythms; love mutants, which disrupt courtship; and memory mutants. Nowadays, mainstream neuroscience mutates mice. Because scientists hate to learn from experience, in its infancy mouse neurogenetics fell into some of the pitfalls that Drosophila neurogenetics escaped from long ago, such as artefacts caused by genetic background, pleiotropism and hidden developmental lesions.

Weiner's book is well written and fun to read, although the question arises, who is the audience? This is scientific reportage and as such should not be expected to provide in-depth analysis of tenets and conclusions. Therefore, those who wish to find a critical assessment of neurogenetics should look elsewhere.

Many questions do deserve serious consideration. For example, what is the price of over-simplification? And what do genes tell us about behaviour? Consider, for example, the remarkable memory mutants. Those isolated so far affect the nuts-and-bolts of cellular plasticity. They are therefore ‘plasticity mutants’. Memories are experience-dependent internal representations whose analysis must involve circuit and system levels. The expectation that neurogenetics per se would explain ‘memory’ thus neglects levels of complexity. With time, Benzer himself realized that Drosophila are not behavioural atoms but rather intricate individuals. He abandoned behavioural for developmental analysis.

No doubt, Weiner was captivated by the eccentric style of Benzerism, and this encouraged him to recite scores of amusing anecdotes. Whether all appeal to the general public, or only to a small cult, is a different question.

Another caveat is also appropriate: students who read the book should not expect mainstream science to follow Benzer's model. Most laboratory work is much more boring than the hunt for bizarre mutants in the forefront of science. Most mentors are much less imaginative, daring and permissive than Benzer. And, unfortunately, the days are long gone when an enthusiastic investigator shared plans without fear, and mutants without a lawyer. This was before business killed fair play.

As for Benzer himself — at the age of 77 he has just discovered a new mutant, Methuselah, that refuses to age.