Scientists have discovered that the ‘Fritillaria delavayi’ plant learned to change color and resemble the surrounding landscape. Such an unusual change occurred only in areas where it is harvested by humans who use it in traditional medicine.
On the slopes of the Hengduan Mountains in China, the delicate Fritillaria delavayi grows. It is a perennial herb with a bright green flower. It begins to bloom at the age of five and does so every June. Its bulb has been used in traditional Chinese medicine for more than 2,000 years, but high prices in recent years have led to increased harvesting.
To survive, the Fritillaria delavayi ‘disappears’ by rapidly evolving and producing gray and brown leaves and flowers that match the background rocks. Since then, collectors can no longer find it as easily as they used to.
Scientists have discovered that the color of the plant leaves is more camouflaged in areas where it is harvested by people.
“Like other camouflaged plants we have studied, we thought the evolution of camouflage of this fritillary had been driven by herbivores, but we didn’t find such animals,” said Dr Yang Niu from the Kunming Institute of Botany, a co-author of the study published in the journal Current Biology.
Botanists measured how close the plants came to the landscape of their natural habitat and how difficult it was to collect them, by asking local people. A computer experiment has shown that it takes people significantly longer to collect camouflage flowers. This suggests that it is people who drive the evolution of this species, because plants that change color have a better chance of survival.
“It’s remarkable to see how humans can have such a direct and dramatic impact on the colouration of wild organisms, not just on their survival but on their evolution itself,” said another study co-author, Dr Martin Stevens from the Centre for Ecology and Conservation on Exeter’s Penryn Campus in Cornwall.
This biological mechanism used by the Chinese plant is quite common in nature and is called mimicry. Normally, plants and animals that have the ability to resemble other organisms or their own environment use them to deceive predators or their natural enemies.
In the case of Fritillaria delavayi, the researchers insist that this is not the only example of plant evolution influenced by the human factor, although there are not many studies on this subject.
“Humans have driven evolution of defensive strategies in other plant species, but surprisingly little research has examined this,” Stevens concludes.