The pioneering geneticist who tried to create a red canary flourished under Hitler. Does that make him a bad guy? Tom Wilkie follows the twists in the tale of Hans Duncker

Tim Birkhead has written a different, and a better, book than he intended.

He is a leading ornithologist, professor of evolutionary biology at Sheffield University, and entranced by birds, their behaviour, evolution and genetics. It was only natural that he would want to write about one of his heroes, the German schoolteacher Hans Duncker, whose breeding experiments with canaries and budgerigars provided profound insights into genetics.

It was naive, though, not to appreciate, until halfway through, that a German geneticist who prospered throughout the Hitler era was likely to have been a proponent of “racial hygiene” and a member of the Nazi party.

It is a tribute to the author’s scholarship, integrity, and humanity that the reader can trace the twists and turns of his reaction to the discovery that his idol had feet of the basest clay. Integrity would not let him cover this up, so he digs deeper, driven by a scholarly wish to know the truth and a human desire that some extenuating circumstance might turn up.

He discovers a post-war de-Nazification interview with the occupying Allied forces in which Duncker denies being anti-Semitic. But more research unearths a public statement by Duncker that contradicts this.

One extenuating circumstance appears that Duncker became a party member fairly late, in 1940. But Professor Birkhead does not consider a wider historical context: the Nazis were long regarded as street-brawling riffraff, and social snobbery rather than ideological conviction stopped many respectable middle-class Germans joining the party.

The book Professor Birkhead wanted to write is still there, and it is a good work of popular science. It is the history of Europe’s obsession with songbirds, from nightingales to canaries, from medieval bird lore to modern science, and from breeding experiments to the limits of genetics. He has done extraordinary research, checking and crosschecking old manuscripts, tracing plagiarism from one document to the next.

The focus of the book is Duncker’s great project, in the 1920s and 1930s, to breed a red canary. To do so, he set out to create hybrids - progeny of matings between birds of several species - believing he could transfer genes that would produce red feathers. Conventional wisdom had it that hybrid animals were sterile - the mule, a cross between a horse and a donkey, is the best-known example.

Duncker succeeded in creating viable creatures with DNA from two separate species, and it is this that justifies the book’s subtitle that Duncker’s canary was the world’s first genetically engineered animal.

There is an element of hype here, and one wonders if Professor Birkhead gave in to an over-enthusiastic editor. “Genetic engineering” now has a precise meaning, confined to the techniques of molecular biology rather than animal breeding, in which specific strands of DNA are snipped out of one organism’s genome and inserted into another’s by the use of chemicals known as restriction enzymes. By this definition, “genetic engineering” did not exist and could not have existed until long after Duncker’s death in 1962.

While the personal story of Duncker turned out to have the sting of Nazism in its tail, the scientific story, too, had a striking twist. The project proved a failure because genetics alone is not powerful enough.

Environmental factors, as much as genes, are involved in turning a canary’s feathers red. Rather as flamingos need shrimps in their diet to stay pink, so genetically predisposed canaries need a source of carotenoids in theirs if they are to be red. Neither “nature” nor “nurture” will do the job alone.

The book’s ending is too pat. Scientists are Whigs when writing history: they judge the past by the standards of today rather than of the time, and thus do not draw the historian’s lesson that today’s standards may appear deficient in the future. Far from being an “abuse” of science, eugenics was promoted by eminent scientists of the day. They meant well, but their good intentions paved a road to Hell. We know more science today, but do we know better, in the wider context, than those eminent predecessors? That is a question this book fails to address.

Tom Wilkie is editor-in-chief at Europa Science, a Cambridge-based science publishing company