Sandra Knapp reviews a study of our symbiotic relationship with pips and pulses.

The Triumph of Seeds: How Grains, Nuts, Kernels, Pulses, and Pips Conquered the Plant Kingdom and Shaped Human History Thor Hanson Basic: 2015. 9780465055999 | ISBN: 978-0-4650-5599-9

I once asked a school class whether anyone present had eaten a plant that day. There was a chorus of “No”, but when toast and cereal were mentioned, all heads began to nod. We sometimes forget humanity's dependence on plants. Plants photosynthesize to provide oxygen, and their unborn offspring — contained in seeds — have supported the development of human civilizations. Biologist Thor Hanson's The Triumph of Seeds relates that deep historical relationship. Cacao beans are packed with food to aid plant growth — which humans, in turn, can exploit. Credit: Holt/Inga Spence/FLPA

This is a charming book, inspired by Hanson's forays into seed identification and dispersal with his young, seed-obsessed son. Its interlocking stories are loosely arranged around the themes of feeding, reproduction, longevity, defence and dispersal. Many will be familiar narratives about plants that have changed the world — such as cacao, chillies, wheat and coffee — but Hanson's twist of looking at human interactions with plants in their embryonic stage is new. Throughout, he scatters interviews and encounters with seed scientists and other biologists, such as Christina Walters of the US National Center for Genetic Resources Preservation in Fort Collins, Colorado. All bring their enthusiasm for their research, and for plants in general, brilliantly to life.

In a seed, the embryo is packaged with food, as in a hen's egg. Their high carbohydrate, protein and/or fat content makes seeds ideal for humans, but Hanson drills in the idea that those riches are not 'for' us. Yet our relationship with seeds is definitely two-way: we nurture wheat and rice, for instance, as much as they nurture us.

Hanson weaves in stories of seed scientists past to underline the long intimacy of the botanical and human. Soviet geneticist and seed collector extraordinaire Nikolai Vavilov, for instance, saw that the hardy, resilient wild relatives of crop plants were key for cross-breeding; his work made the Soviet Union a leader in agricultural improvement, but he starved to death, imprisoned in a gulag for criticizing the pseudoscientific ideas of biologist Trofim Lysenko, who had Stalin's support. And nineteenth-century US botanist William James Beal set up an experiment that is still running, burying bottles of sand and seeds in Michigan soil to test the seeds' viability over time.

Hanson's foray into the biology of chillies (fruits, and members of my favourite plant family: the Solanaceae, or nightshades) is a wonderful example of the perils of just-so stories. Simplification is a good first step, but in the end, nature is astoundingly complex. As Hanson reveals, the heat we feel when eating a chilli is not just the plant's defence against mammalian predators; it is caused by a potent antimicrobial agent that protects the seeds from fungal attack. Fruits and other plants are thus well armed, chemically as well as physically, to protect the next generation.

There is more to the ideal seed 'packaging', the fruit. Unripe fruit contains chemical compounds, such as tannins, that can taste bitter — a potent reminder to the predator to wait, because the seeds are ready for dispersal only when the fruit is ripe. And once animals (including us) eat them, the seeds get a free ride to a new habitat. This is all, in essence, plant behaviour — the botanical equivalent of chest-beating or protecting a child. However, it often passes us by because it occurs on a timescale different to that of animal movement or thought.

Credit: From Seeds — Time Capsules of Life/R. Kesseler, W. Stuppy/Papadakis Hanson touches briefly on genetic engineering, but then limits his discourse to our social preoccupation with seeds. It is interesting that we seem to react more strongly to the genetic engineering of seeds than to that of humans; a comparison of these areas would contribute something new to the story.

I had other quibbles. There is a saying: “Knowledge is knowing that a tomato is a fruit, wisdom is not putting it in a fruit salad.” That underlines an important point: classification may seem pernickety, but it is key. Hanson largely abjures botanical terminology, and this is unfortunate. Part of the joy of plants is their extraordinary diversity and the mind-bending ways in which different parts of the organism serve different functions in the life cycle; conveying either demands some use of technical terms. Hanson also indulges in some slightly grating cultural parochialism. For example, chapter 3 is entitled “Sometimes you feel like a nut” — from an advertising ditty for the US chocolate bar Almond Joy. Even I, a transplanted North American, failed to get the reference straight away.

A portion of the proceeds from the book will be shared with worthy seed-related endeavours. Among them are the Millennium Seed Bank at the UK Royal Botanic Gardens, Kew, which is tasked with preserving plant genetic diversity; and the Crop Trust in Bonn, Germany, which runs projects such as the Svalbard Global Seed Vault to conserve crop diversity. But seed banking, however laudable, cannot on its own sustain a dynamic planet. That requires a change in how humans see the rest of life. The Triumph of Seeds will engender thoughtful consideration of our joint future.

Author information Affiliations Sandra Knapp is in the Department of Life Sciences at London's Natural History Museum. Sandra Knapp Authors Sandra Knapp View author publications You can also search for this author in PubMed Google Scholar Corresponding author Correspondence to Sandra Knapp.

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About this article Cite this article Knapp, S. Plant sciences: Seeds and civilizations. Nature 519, 288–289 (2015). https://doi.org/10.1038/519288a Download citation Published: 18 March 2015

Issue Date: 19 March 2015

DOI : https://doi.org/10.1038/519288a