Plant geneticists have discovered that plants share many genes with animals and humans. They share so many, in fact, that Professor Daniel Chamovitz, director of Tel Aviv University’s Manna Center for Plant Biosciences, said we may have to reconsider what characterizes us as human.

Chamovitz wrote about the discovery in his new book, “What a Plant Knows,” and claims that plants actually have senses such as sight, smell, touch and taste.

The recent findings were discovered when Chamovitz was studying the way plants react to light. He found that a group of genes was responsible for a plant “knowing” whether it was in the light or in the dark. He first believed that these genes were specific to plant life, but was surprised to later identify the same group of genes in humans and animals.

"The same group of proteins that plants use to decide if they are in the light or dark is also used by animals and humans," Chamovitz said. "For example, these proteins control two seemingly separate processes. First, they control the circadian rhythm, the biological clock that helps our bodies keep a 24 hour schedule. Second, they control the cell cycle—which means we can learn more about mutations in these genes that lead to cancer."

In experiments with fruit flies who had a mutated version of one of these genes, Chamovitz and his fellow researchers observed that the flies not only developed a fly form of leukemia, but also that their circadian rhythm was disrupted, leading to a condition somewhat like permanent jet-lag.

Plants use light as a behavioral signal, letting them know when to open their leaves to gather necessary nutrients. This response to light can be viewed as a rudimentary form of sight, Chamovitz contends, noting that the plants "see" light signals, including color, direction, and intensity, then integrate this information and decide on a response. And plants do all this without the benefit of a nervous system.

And that's not the limit of plant "senses." Plants also demonstrate smell—a ripe fruit releases a "ripening pheromone" in the air, which is detected by unripe fruit and signals them to follow suit—as well as the ability to feel and taste. To some degree, plants also have different forms of "memory," allowing them to encode, store and retrieve information.

The findings could cause scientists to rethink what they know about biology. The research could also lead to the development of improved plant genetics.