Researchers have documented the first evidence of a plant camouflage that has evolved in response to human predation.
There have already been crescendo examples of animals evolving to divert their trajectories away from humans. Perhaps the largest documented case is the increase in elephants being born without tusks, a biological trend that appears to be a consequence of human actions. However, this type of evolutionary behavior had not previously been observed in plants... until now. New research revealed the strange camouflage of a Chinese plant that seems to be a product of evolution as a mechanism to hide from humans. They do not wish to be found by the human species.
The research was carried out by experts from the Kunming Institute of Botany in China in collaboration with sensory ecologist Martin Steven of the University of Exeter. "It is remarkable to see how humans can have such a direct and dramatic impact on the coloration of wild organisms. Not just on their survival but on their very evolution," says Steven.
Harvesting or predation?
The plant in question is the Fritillaria dealvayi, a Chinese plant that has been harvested for centuries by herbalists in the region. Its bulbs are ground into powder to treat respiratory tract conditions such as coughs. One kilogram of cough powder requires about 3,500 bulbs, which means that thousands of plants must be depredated to obtain this remedy. To do this, collectors search the loose rock fields that line the slopes of the Himalayan mountain ranges, where the plant lives.
Previously they used to find the flower very easily, as its vibrant green leaves would give it away among a field of dull brown rocks. But this seems to be changing, as the plant, which only produces one flower each year, has evolved camouflage mechanisms to keep it safe from humans. Perfect camouflage has transformed the intense green coloration into dull gray leaves that blend well with the background of its habitat.
What is fascinating in this case is that in regions where the flower is not usually disturbed by humans, its leaves and stems retain their characteristic bright green color. Same plant, two different situations, and a camouflage mechanism that has apparently been developed to divert humans from its path.
The diversion of the natural course in the hands of mankind
There are several cases where plants develop camouflage systems to avoid being eaten by herbivores. The researchers first followed this path. However, when looking for such animals, they found no evidence of herbivores feeding on Fritillaria. No bites or other signs of animal predation were found, so the line of the investigation changed course. Experts realized that humans might be the cause of this defense mechanism. "Many plants seem to use camouflage to hide from herbivores that may eat them, but here we see camouflage evolving in response to human foragers," the authors say.
The team's findings suggest that there may be other cases where plants have evolved camouflage systems to deflect human attention. But since this is an apparently new revelation in plant behavior, there is not much research on the subject. In the opinion of the researchers, "the current state of biodiversity on earth is determined as much by nature as by ourselves". And we should be aware of the great responsibility this entails.
Text and photos courtesy of Ecoosfera
Translated by María Isabel Carrasco Cara Chards