Climate Change Will Destroy Your Popcorn Habit

If you were planning on munching on popcorn while the world burns around you, archaeologists have some bad news.

A new study, published Thursday in the journal Science, indicates that unless we act, and act fast, climate change could threaten everybody’s favorite meme-able snack: popcorn.

The new research, which looks at the evolution of maize in the United States over thousands of years, indicates that the corn’s adaptation to new climates was a slow process. And even with modern technology, it seems helping corn adapt to our rapidly changing world won’t be easy.

Maize was first domesticated in the tropics of southern Mexico about 10,000 years ago. But people began to bring it north, with domesticated corn arriving in the southern United States about 4,000 years ago. In the deserts of the southwest, the plant quickly became a staple.

But the plant appears to have languished in more temperate regions for another 2,000 years. The researchers believe this is a result of corn’s difficult to adapt to frost and other aspects of a cooler climate.

In their analyses of maize over time, the scientists took archeological samples of maize from the Turkey Pen site in southern Utah. (Fortunately, the paper says, “preservation of genetic material in TPS maize was excellent.”) They then ran the plants through genomic tests that compared them with modern corn strains. From there, they could estimate the number of days it took for each plant to flower.

The results were striking. Over 1,900 years, humans artificially selected maize that grew before winter came. Thanks to their dedicated farming, corn eventually evolved to the point it could become a staple crop even far outside its original tropical zone.

Though this persistence gave us the five types of corn we know and love today, including the self-explanatory popping corn and the summer favorite sweet corn, the complexity of maize evolution indicates some trouble on the horizon, the authors of the paper say.

The Earth’s climate is changing — with or without corn’s approval. Extreme weather events are more likely and the global temperature is rising, presenting problems to crops that struggle to adapt to new environments.

“We see incredible genetic variation in maize, but it took a long time to accumulate enough of the early flowering variants in the same plant to adapt to short growing seasons,” says Kelly Swarts of the Max Planck Institute for Developmental Biology. “A trait like flowering time is so complex that it involves changes to hundreds of genes.”

“But we won’t have the luxury of millennia to adapt maize to the environmental challenge of global warming,” she adds. In order to prevent against popcorn peril, Swarts and her colleagues advocate for genome modification, precision breeding, and other scientific techniques that can protect vulnerable plants. Popcorn isn’t the only food that will be effected by climate change, however, and lab-based interventions aren’t the only bandaid.

Studies show that many staple crops like rice have lower yields when the temperature rises. Not only does this mean people will have less rice to eat, but animals who rely on basic grains will suffer, too. Experts think this will create a severe dent in our supply of animal-based proteins (aka beef patties). What’s more, food security experts advocate not just for technological fixes but new diets altogether. Johanna Kelly, the filmmaker behind The Gateway Bug says bug-based cuisine is the major key.

But whatever the future of food holds, it’s clear you should hug your popcorn tight tonight.

Abstract: People introduced maize to the southwestern US by 4,000 years ago; full agriculture was established quickly in the lowland deserts but delayed in the temperate uplands for 2,000 years. We test if the earliest upland maize was adapted for early flowering, a characteristic of modern temperate maize. We sequenced fifteen 1,900-year old maize cobs from Turkey Pen Shelter in the temperate Southwest. Indirectly validated genomic models predicted that Turkey Pen maize was marginally adapted with respect to flowering, as well as short, tillering and segregating for yellow kernel color. Temperate adaptation drove modern population differentiation and was selected in situ from ancient standing variation. Validated prediction of polygenic traits improves our understanding of ancient phenotypes and the dynamics of environmental adaptation.