Campus researchers discover new organisms, expand tree of life

US Navy Marine Mammal Program/Courtesy

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In a joint collaboration with researchers from colleges around the globe, a campus professor published a study Monday that uncovered new microbes, expanding the commonly known tree of life.

Jillian Banfield, campus professor of earth and planetary science, in tandem with Laura Hug, a University of Waterloo assistant professor of biology, collected samples from various sources — including the groundwater from a freshwater shallow aquifer system in Colorado, dolphins’ mouths and meadow soil — in order to discover new microbes, or microorganisms that cannot be seen by the naked eye.

In the study, researchers collected samples of organisms that have either been cultivated or uncultivated in a laboratory setting in order to show the vast diversity of microbes, said Alex Hernsdorf, a campus graduate student who worked on the study.

“We’re essentially unaware of the diversity of life that exists in small organisms,” said Ronald Amundson, a campus professor of environmental science, policy and management and a collaborator on the study. “Nobody was ever aware that these organisms exist and we didn’t even understand that they were present in nature. We’re just starting to see really the diversity of life that is not really easy for us to access.”

According to Amundson, Banfield and her colleagues discovered last year that some of the organisms that belong to the candidate phyla radiation group, or CPR, in the tree of life create a new branch on the tree that is related to the bacteria.

“That is a fundamental addition to the diversity of life that hasn’t been seen before,” Amundson said.

The tree of life is a visual representation of the evolutionary relationships among living organisms, explained Abby Dernburg, a campus professor of molecular and cell biology. It is organized so that the more closely related organisms are, the more closely connected their branches will be on the tree.

Though the study was funded by multiple sources, the bulk came from the Department of Energy’s Office of Biological and Environmental Research. Because Hug and Banfield worked with a large number of collaborators, each researcher had funding coming from other sources as well, including NASA and the Ministry of Economy, Trade and Industry in Japan, among others.

Hug is starting a new lab at the University of Waterloo and will continue her research in diversity in the hopes of discovering and adding new branches to the tree of life. Banfield’s campus lab will be continuing with this project in investigating the relationship of the CPR to the rest of the bacteria.

Several campus professors and researchers agreed that the study illustrates the magnitude of the earth’s diversity.

“I think that we can all agree that there are a great diversity of life forms on earth, but I think one of the things that this study showed us is that the diversity of what we can see with our eyes really only scratches the surface of what is really out there,” Hernsdorf said. “I think our paper is going to change the way people think about evolution.”

Hug echoed Hernsdorf’s sentiments, and added that their discovery would spark new investigations among researchers.

“It’s important to have a perspective for where students stand with variety of life on earth,” Hug said. “From a scientific perspective, trees of life have historically been generators of hypotheses for future studies. The way that these have connected different groups have led to questions about how life began and questions about how these organisms interact. I think that is one of the really valuable things a tree can give — it can generate new questions and new directions for research.”

Contact Chantelle Lee at [email protected] and follow her on Twitter at @ChantelleHLee.