Leonora Bittleston

What do rainforests and human guts have in common?

While they may not appear to have many similarities, both are complex ecosystems. And studies involving carnivorous pitcher plants may inform our understanding of both systems.

Just as our guts curate the microbiota they contain, so too does the pitcher plant. Organisms living in our guts allow us to extract nutrients from sources that would otherwise be difficult to digest, and scientists think that pitcher plant inhabitants do the same thing. In American pitcher plants, this means processing the tough exoskeletons of one of their main sources of nutrients, insects.

For Leonora Bittleston, who studies the interactions between pitcher plants and the organisms found within them, these unusual florae offer a lens into evolutionary processes and the relationship between an environment and its inhabitants, no matter how big or small. 

But while pitcher plants are certainly unusual, they are not strictly speaking unique: As unlikely as it sounds, pitcher plants have actually evolved three separate times, in North America, Southeast Asia, and Australia.

As a prominent example of convergent evolution, pitcher plants are remarkable enough. Even more remarkable than the similarities across independently evolved lineages of pitcher plants, however, are the differences among species within the same pitcher plant lineage in a single habitat. Different species of pitcher plants in the same habitat display markedly different internal communities, suggesting that individual species are able to influence the contents of their internal environments significantly.

The mechanism for doing so is the focus of Bittleston’s work. As she explains, “We can use these tiny ecosystems to look at broader patterns in the world.” From a pitcher plant to a gut to a rainforest, certain environments may choose their inhabitants as much as the other way around.