By analyzing the genome of the Australian pitcher plant and comparing it to those of other types of carnivorous plants elsewhere in the world, the authors of a new study have discovered that all of them underwent similar molecular changes, despite differences in time and location.

“We’re really looking at a classic case of convergent evolution,” Victor Albert, a biologist with the University of Buffalo and the co-leader of the research, told Scientific American on Monday. Despite being continents away from each other and evolving several millions of year apart, these plants all appear to have developed very similar digestive processes, his team found.

Unlike the Venus flytrap (Dionaea muscipula), which entombs its prey in a jaw-like structure if triggered, pitcher plants trick insects into a slippery cup-shaped leaf that keeps them from getting out once they fall in, explained NPR. Once the insect is trapped, its exoskeleton is slowly broken down by a liquid, allowing the plant to obtain the nutrients it needs in order to survive.

“It’s kind of counterintuitive that a plant is actually using an animal for some of its food. We usually think of animals, such as ourselves, as using plants,” Albert said, adding that his study has discovered that “the pathways to evolving a carnivorous plant, and in particular, to a pitcher plant, may be very restricted.”

‘Similar genetic building blocks’ found in multiple pitcher plants

To investigate what genetic changes may have occurred to allow flora to capture and to digest insects, the study authors first examined the genome of the Australian pitcher plant (Cephalotus follicularis). These plants, they explained, have two different types of leaves – one group that is responsible for photosynthesis, and one which become the bug-trapping pitcher.

By sequencing the DNA of the Australian pitcher plant, they found genes that are specific to the pitcher leaf, and are rarely or never found in other parts of the plant. As they reported earlier this week in the journal Nature Ecology and Evolution, they believe that this DNA is responsible for the development of the trap mechanism. Furthermore, by comparing it to samples from unrelated American and Asian pitcher plant species, they found similar digestive processes at work.

In short, despite the fact that all three types of pitcher plants evolved in different locations and at different times, they all developed similar mechanisms for trying to cope with environments with nutrient-poor soil by trying to obtain nitrogen and phosphorus from trapped insects. Furthermore, they each shared “similar genetic building blocks,” co-author Kenji Fukushima told Gizmodo.

Albert’s colleagues are praising the findings. Thomas Givnish, who studies plant evolution at the University of Wisconsin, called it “a really unique study and the first of its kind” in an interview with NPR while Massachusetts ecologist Aaron Ellison told Scientific American that the research was important because it demonstrated that convergent evolution for carnivorous plants could be proven to occur down to even the molecular level.

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Image credit: Thinkstock

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