Genetic Literacy Project Next time you bite into a slice of watermelon or a cob of corn, consider this: These familiar fruits and veggies didn't always look and taste this way.

Genetically modified foods, or GMOs, inspire strong reactions nowadays, but humans have been tweaking the genetics of our favorite produce for millennia.

While GMOs may involve splicing genes from other organisms (such as bacteria) to give plants desired traits — like resistance to pests, selective breeding is a slower process whereby farmers select and grow crops with those traits over time.

From bananas to eggplant, here are some of the foods that looked totally different before humans first started growing them for food.