Although there is little doubt that humans were inspired by birds when they developed aircraft, it is usually less well appreciated that aircraft also increased our understanding of bird’s flight. The artificial recreation of a biological system may thus improve our understanding of its functioning. Something similar has occurred with agriculture, albeit on a longer time scale. The start of human agriculture some 10,000 years before present, ultimately offered Darwin a rich source of inspiration for developing his ideas on natural selection, reflected in the title of the first chapter, “Variation under domestication,” of his masterpiece. He found his best argument for the power of natural selection in the artificial selection of domesticated organisms by humans. Surprisingly, the opposite, the application of evolutionary ideas to agriculture, has not been exercised until recently. Ford Denison now fills this gap with a book entitled Darwinian Agriculture. Denison sees three core principles of Darwinian agriculture that should lead to productive, efficient, stable, and sustainable agriculture. First, prolonged natural selection has rarely missed simple, trade-off free improvements. Simple improvements by genetic engineering are therefore highly unlikely. Second, competitive testing is more rigorous than testing merely by persistence. Ecosystems may be stable, but their stability is not a result of natural selection among ecosystems. Ideas from ecosystem patterns thus require more rigorous testing than ideas inspired by the competitively tested individual adaptations of wild species. Third, we should hedge our bets with a greater variety of crops and ideas. These principles are worked out in 12 chapters. The book sets out to formulate a research agenda for yet another application of evolutionary theory after the now well-established research field of Darwinian medicine. Similar to Darwinian medicine, Darwinian agriculture is broad, ranging from applying evolutionary insights to efficient disease control, artificial selection of complex traits, artificial group selection, and selection for better mutualists. The examples Denison uses reflect this diversity. Throughout the book, Denison balances between two extreme views on agriculture, which he both rejects. The one view is that biotechnology will solve all current and future problems, and improve agriculture by simple means. Denison argues that it is highly unlikely that millions of years of natural selection have missed simple, trade-off free opportunities. Therefore, “trade-off blind biotechnology” will rarely work, at least not by simple tricks. For example, increases in drought tolerance usually will lead to reduced photosynthesis. A thorough review of the literature shows that neither yield potential, photosynthetic efficiency, water use efficiency, or nutrient use efficiency have increased very much recently, despite the promises of biotechnology. Denison identifies two classes of genetic improvement, where he “does” see a role for biotechnology. First, while it is unlikely that “simple” solutions have been missed by natural selection, this may not be true for “complex” solutions. The reason is that such solutions will require multiple genetic changes, some of which individually may decrease fitness. Therefore, to achieve such solutions via natural selection would require the simultaneous occurrence of multiple mutations, which is highly unlikely. Evolution thus may have stopped at a suboptimal solution before a better solution was found. Although, in principle, biotechnology can be useful to achieve such complex changes, these changes will also be the most challenging to achieve via biotechnology and will require a thorough understanding of the biology of the organism. The failure so far to transfer C4 photosynthesis from corn