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This is scientific American's 60-Second Science, I'm Karen Hopkin, this'll just take a minute.

If there’s anything better than a fresh, ripe, tomato, it’s a gigantic fresh, ripe tomato. And thanks to a couple of mutations, that’s exactly what we all enjoy every time we grab a tomato from the farmer’s market or the grocery store. In the wild, tomato plants actually produce some pretty small fruit. Today’s cultivated varieties serve up tomatoes that are a thousand times larger. This yummy enormity comes from mutations that affect the activity of two genes³: one that controls cell division, so the more cells there are in a tomato, the bigger that tomato will be; and another that controls how many seed-bearing compartments⁴ each fruit has. Again, the more compartments the bigger the fruit.

The compartment-number mutation¹, discovered by scientists at Cornell University, is described online in the current issue of Nature Genetics. The researchers found that no strains of wild tomato carry this mutation, which affects a gene² called fasciated. While all of the large-fruited modern varieties they surveyed have it, this suggests that the mutation occurred relatively⁵ recently in tomato history, and that breeders then shared it with all their tomato-loving friends. So you can thank those fasciated mutants for teeing up your next BLT.

Thanks for the minute, for Scientific American 60-Second Science, I'm Karen Hopkin.