By Meghan Chua
Lena Vincent started her career as a graduate student with big questions: How did life begin? Does life exist elsewhere in the universe?
As Vincent found out, a young field in science was cropping up to answer these very questions. Though her training up to that point had been in molecular biology, Vincent now considers herself an astrobiologist.
“Realizing that you can turn these existential questions that everyone asks themselves into a scientific career was really exciting,” said Vincent, a PhD student in David Baum’s lab at UW–Madison. “I haven’t really looked back since.”
Vincent studies the origin of life by searching for life-like behaviors in systems of molecules. In a lab at the Wisconsin Institute for Discovery, Vincent and her colleagues create conditions that they think could be conducive to life-like patterns forming. Life, though, might not look the way we know it here on Earth.
“It’s kind of a difficult thing for us to think about, because we’re very tempted to overlay our definition of life, based on our understanding of life as we know it, in that search,” Vincent said. “What we’re trying to do and what other astrobiologists are trying to do is being a little bit more agnostic [to] what life might look like outside of Earth and try to imagine more exotic forms, perhaps ones that we would miss if we were calibrating all of our detection methods based on life as we know it.”
The Baum lab looks for two necessary characteristics of life in its experiments. First, something that is alive self-propagates, making more of itself. Second, life becomes increasingly complex through evolution.
To look for these characteristics, they use a novel approach called chemical ecosystem selection. It relies on a chemical process in which molecules help catalyze each other’s formation. With enough reactants that can feed this process, the cycle repeats and the different types of molecules form one another over and over again. The Baum lab hypothesizes that molecules already present early in the Earth’s life did not need to be part of a living system to start with but may have self-organized through such a process. Over time, those groups of molecules could possibly evolve and become increasingly complex.
To test whether chemical ecosystem selection can result in lifelike patterns, Vincent uses a chemical soup of molecules and mixes in other components, like minerals, that may also play a role. After the initial batch is mixed, she transfers a small amount to a new container with fresh chemical components that could feed any existing molecule systems so they can self-propagate.
To replicate an early Earth environment, the team had to exclude oxygen from their mixtures, and use for their experiments a chamber filled with a specialized gas mix made mainly of nitrogen, hydrogen, and carbon dioxide. They’ve also explored using UV lights to incorporate UV radiation and may use ovens or incubators to create different temperature conditions.
Last year, the lab found a set of conditions that seemed to suggest the emergence of a feedback loop of molecules that was sustained by the chemical mixtures. This year, Vincent has received NASA’s Future Investigators in NASA Earth and Space Science Technology Award.
With the support of the NASA award, Vincent will work to analyze what molecules are involved and how the feedback loop changes over time. She will also test out more conditions, including a set meant to closely mimic Saturn’s moon Titan.
“The key with this is that we’re not going to learn a whole bunch based on just one isolated incident,” Vincent said. “We’re going to have to mine through lots of different conditions and see what kind of interesting chemistry comes out of them and compare them and try to extract some generalities among them.”
Vincent has also helped spearhead the Origins of Life, Artificial Life, & Astrobiology initiative, or OoLALA, which raises awareness of astrobiology research happening across different departments at UW–Madison and gives astrobiologists a chance to connect with one another and with prospective scientists. As a relatively young field of science, Vincent said it is often difficult to find information on astrobiologists at universities even where that type of research is done. OoLALA held a successful seminar series in spring 2019 that showed the breadth of astrobiology research and connected visiting researchers to UW–Madison faculty and students. The initiative hopes to hold more seminars in the future.
Vincent started her astrobiology career with big questions – how did life get started? Does it exist on other planets? – questions that haven’t been answered yet and may not be answered any time soon. But she remains optimistic.
“Some people might find that a little intimidating to think, why would you join an area of science where there are literally no answers at this point?” Vincent said. “But on the other hand, it’s such an awesome way to be creative and to think outside the box. I think along the way, there are definitely things we’re going to be able to answer. And eventually, I’m optimistic about our odds of answering both of those questions. It might just take a little more time and a little more creativity.”