Are kale, broccoli and Brussels sprouts really all the same plant?

Kale, broccoli, Brussels sprouts, cabbage, cauliflower, collard greens and kohlrabi have unique nutritional values, and we think of them as distinct vegetables. Yet, they all share the same species name. Could they all really come from the same plant?

The short answer is yes, and humans are responsible for the differences among these veggies.

"It is all one plant, Brassica oleracea, that humans have selected over multiple generations to have these varying vegetables that we all enjoy eating," Makenzie Mabry, an evolutionary biologist at the Florida Museum of Natural History, told Live Science.

Chris Pires, an evolutionary biologist who studies crop science at Colorado State University, calls these veggies "the dogs of the plant world." All pet dogs (Canis lupus familiaris) are the same species, domesticated from wolves (Canis lupus), and they come in different varieties, or breeds. Similarly, broccoli, cauliflower, kale and the other aforementioned vegetables were also domesticated from the same species, B. oleracea.

Related: Where did watermelons come from?

Of course, many crops were cultivated for specific traits too, such as heirloom tomatoes. But unlike those crops, which are bred for different colors, tastes and sizes, Brassica varieties are bred from the plant's different physical parts.

"We domesticated all of the plant parts," Pires noted. "The stem, the inflorescence [flower cluster], the leaf, the underground parts."