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1 .This is Scientific American 60-Second Science. I'm Karen Hopkin. This'll just take a minute.
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2 .Nothing says summer like a sweet ear of corn.
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3 .But that treat would be much harder to eat if it weren't for a crucial mutation.
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4 .The change, in just one letter of the DNA code, appears to have cracked the hard casing that covered every kernel in corn's wild ancestor.
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5 .That's according to a study in the journal Genetics.
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6 .Corn was domesticated from a wild grass called teosinte some 9,000 years ago.
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7 .But how did our ancestors make maize the agricultural marvel it is today?
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8 .Seems they selectively propagated plants with a particular mutation, one that made the kernels more accessible to hungry Homo sapiens.
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9 .The researchers compared the DNA of 16 varieties of modern corn and 20 types of teosinte.
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10 .And they found a single, key mutation that is present in modern corn but absent in its wild-grass ancestor.
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11 .This genetic hiccup disrupts the activity of a protein called tga1.
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12 .In teosinte, the tga1 protein directs the formation of a hard shell around every corn kernel.
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13 .But the modern maize mutation gives tga1 a new set of marching orders.
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14 .The mutant protein turns the ear inside out, converting the seed cases into a cob that holds all the kernels in place.
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15 .When the researchers reversed the effects of the mutant protein, the ancestral seed-case remnants started to reappear.
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16 .The results suggest that even minor genetic changes can lead to some pretty tasty developments.
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17 .You might call it a-maize-ing.
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18 .But that would be corny.
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19 .Thanks for the minute, for Scientific American 60-Second Science. I'm Karen Hopkin.
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