The natural world is full of examples of what biologists call convergent evolution — instances where unrelated creatures developed similar traits in response to similar evolutionary pressures.
But can that convergence include the interactions of different species that evolve under similar conditions?
The early evidence, says Leonora Bittleston, suggests the answer is yes.
As part of a study conducted while she was a graduate student in the labs of Naomi Pierce, the Sidney A. and John H. Hessel Professor of Biology, and Anne Pringle, the Vilas Distinguished Professor of Botany at the University of Wisconsin, Madison, Bittleston found that the “miniature ecosystems” housed in pitcher plants from opposite sides of the world are strikingly similar, suggesting that there may be something about the plants themselves that drives the formation of those communities. The study is described in an Aug. 28 paper published in eLife.
“These plants, the Nepenthes in Southeast Asia and Sarracenia in North America, evolved completely independently … and because they’re like little aquatic islands, they can be used as model systems to study community ecology,” said Bittleston, now a postdoctoral fellow at the Massachusetts Institute of Technology. “They have a whole little microcosm inside them — even though they eat insects, there are aquatic insects that can only survive in pitcher plants, but there are also aquatic mites, protozoa, rotifers, fungal yeasts, and bacteria.”
To capture an image of that community, Bittleston, Pierce, Pringle, and their collaborators from the Universiti Malaysia Sabah and the University of Malaya turned to a process called DNA barcoding, which uses a short section of DNA to identify different species.