Cary Fowler is an easygoing, soft-spoken Tennessee native who travels the world with an urgent message: The human race may starve to death. If that threat becomes likely, however, people can turn to the biological archive that director Sandy McLeod's documentary calls The Seeds of Time.

The film, which is largely a portrait of Fowler, opens with him at a fishing hole near his childhood home in Memphis. But the agriculturist hops from there to Rome, where he served as executive director of the Global Crop Diversity Trust, and to a frozen island in northern Norway, where he established the Svalbard Global Seed Vault. This contains seeds of many of the rare species global agribusiness corporations think farmers don't need anymore.

Other stops include Iowa, where the Seed Savers Exchange encourages biodiversity with Midwestern small-town practicality; St. Petersburg, which turns out to be the Eden of crop preservation; and the Andes, where an institution with the delightful name of the International Potato Center is reintroducing forgotten varieties of the region's principal crop.

Peru is one of the locales where Fowler's mission brushes against controversy. The indigenous potato farmers need new — which is to say, old — varieties because the mountains are getting warmer. Farmers are moving up the slopes to new fields, where some of the long-unused types of potatoes may grow better.

This is a climate change organization, Fowler told his colleagues when he joined the Global Crop Diversity Trust a decade ago, an opinion he says surprised them. Such ideas are less startling now. The combination of genetically indistinguishable "indenti-crops" and hotter, drier farmlands could mean "you've set yourself up for an epidemic," he says.

The urgency of Fowler's project is underscored by his personal history, which includes two bouts of cancer, both of which doctors said would kill him. Buried even deeper in the film's layered history is the tale of Nikolai Vavilov, the pioneering Soviet seed saver. He died in prison, the victim of Stalinist whim, during the Nazi siege of what was then Leningrad. Meanwhile, some of his colleagues succumbed to starvation rather than eat the precious specimens their boss had collected.

The average eater may be content with one kind of tomato and a single variety of corn, but crop activists have profound attachments to less popular plant varieties. In one poignant moment, the film shows a Filipina activist in tears as she describes how her country's seed bank was destroyed.

McLeod stitches together these overlapping strands with skill, if not much flair. Brief animated interludes suggest an industrial film, as does Kris Bowers' blandly jaunty score. Henrik Edelbo's cinematography is more impressive, especially when capturing such dramatic landscapes as the sides of the Andes or that icy island north of the Arctic Circle.

The Seeds of Time would have more narrative kick if the filmmakers had spent more time with Fowler. Too often, he tells us about incidents that ideally should be more than secondhand anecdotes. But the scientist's biography alone is compelling, from his 1960s days as a white teenage member of the NAACP to today's dire forecasts about the future of agriculture.

When Fowler warns of "mass extinction," he's not referring to tigers, chimpanzees, and polar bears. He's talking about breakfast, lunch, and dinner.

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