Study: Tubers are at root of evolution

Edible roots might have acted in the split between primates and early hominids.

Than Tibbetts

Never underestimate the power of the potato.

Anthropologists have focused on meat and hunting as the primary means for evolutionary change, but anthropology professor Greg Laden said he believes change came at the hands of ancient relatives of the lowly vegetable.

Laden’s paper, written with Harvard University anthropology professor Richard Wrangham, outlines roots as playing a large role in the split between chimpanzeelike primates and early hominids 5 million to 7 million years ago.

The edible roots were used as “fallback foods,” Laden said, or in other words, “the foods you eat when you’re starving to death.”

The lineage of chimpanzees stayed in the forests, while the early hominids moved toward the open savannas. When meat and other primary foods became scarce, the early hominids learned to rely on the roots, which are more abundant in the savanna, the researchers said.

Some anthropologists speculate the move happened as early hunters followed game into the plains, but it was the availability of edible roots that would allow them to survive, the researchers said.

“This doesn’t negate the importance of hunting,” Laden said.

The chimplike creatures might have been compelled to expand their range further into the open as more roots were found in the savanna, Laden said.

“This is like a conveyor belt, in a way,” he said.

Both researchers lived with the Efe pygmies in Africa’s Ituri forest and said their experiences there led to this research.

“During the hunger seasons, during the times when the pygmies were short of food, there was a clear tendency to go off and look for the relatively few roots that could be found,” Wrangham said.

But instead of looking in the forest, the pygmies searched in rocky outcroppings, he said.

“Preferred foods are generally so easy to eat that evolution has not led to any particular types of adaptations,” he said.

Wrangham said early hominids better suited to eating roots would have been more likely to survive and pass on their genes.

Laden and Wrangham’s research comes amid particular controversy in evolution as a court case in Dover, Pa., looks at whether intelligent design should be taught alongside evolution in science classrooms.

Intelligent design – the belief that a higher power created life as it is today – does not fit into the current picture of science, said Randy Moore, a General College biology professor.

“If science teachers have to go in and teach or mention (intelligent design), it will corrupt science and trivialize faith,” he said.

Nevertheless, Laden and Wrangham are already advancing their theory of fallback foods. Laden will soon publish a paper on rodents and fallback foods, and Wrangham will do the same about primates.

“Evolution driven by fallback foods is going to be a new way of looking at evolution,” Laden said. “It will have widespread impacts.”