Carnivorous plants are the coolest. These seemingly out-of-place organisms behave like other plants in nearly every way – except for the fact that they feed upon the flesh of insects and small animals. These plants have also shown themselves to be resilient in the face of ecological stresses, adapting to changes in their environment such as developing a taste for invasive species or allowing some of their would-be victims to escape in order to lead more prey back to their sweet, sweet nectar.
While they have been studied extensively, botanists have for years been perplexed over the evolutionary history of carnivorous plants. Several distinctly different species of pitcher plants show vastly different evolutionary lineages, yet have developed strikingly similar mechanisms of carnivory. In the Australian, Asian and American pitcher plants, genomic analyses revealed that each plant developed carnivory independently of one another without a common carnivorous ancestor, and scientists have been unable to explain how. Until now, that is.
Botanists at the University of Buffalo have published research claiming to have solved this long-standing evolutionary mystery. In their recent Ecology & Evolution publication, the researchers claim to have discovered the shared evolutionary adaptation these plants used to develop the ability to digest flesh:
Analysis of digestive fluid proteins from C. follicularis and three other carnivorous plants with independent carnivorous origins revealed repeated co-options of stress-responsive protein lineages coupled with convergent amino acid substitutions to acquire digestive physiology. […] This result suggests that orthologous genes were repeatedly co-opted for digestive functions in independent carnivorous plant lineages.
In other words, according to this research, these plants co-opted certain proteins used to defend against diseases and transformed them into digestive enzymes which can break down insect chitin and other tissues. The adaptation was likely in response to the nutrient-poor habitats in which pitcher plants usually found.
According to University of Buffalo biologist Victor A. Albert, the evolutionary similarity of these plants’ carnivory suggests evolution might have a certain set of genetic ‘rules’ all organisms must follow:
It suggests that there are only limited pathways for becoming a carnivorous plant. These plants have a genetic tool kit, and they’re trying to come up with an answer to the problem of how to become carnivorous. And in the end, they all come up with the same solution.
Thus, as Dr. Ian Malcolm will be immortalized for saying, life, uh, finds a way – no matter how distantly related. Three separate species of plants, all developing the same ability to eat animals independently of one another through the same adaptation. Studies like this one suggest that given the fact that all life might have begun in the same protein-rich primordial soup, it’s not too far-fetched to suggest that all living things likely play the game of life according to the same set of rules. But, you know the best thing about rules? They’re meant to be broken.