“Immediately, to me, it evokes the potential for life beyond Earth,” says Lena Vincent, a graduate student at the Wisconsin Institute for Discovery, whose research in the lab of botany professor David Baum focuses on the chemical origins of life.
Vincent stumbled upon astrobiology (which has ties to the University of Wisconsin–Madison 1958 Nobel Laureate, Joshua Lederberg) by accident years ago while contemplating the future of her research career at a time when she was spending her days peering through a microscope at cancer cells and observing the patients in and out of the cancer center where she worked.
She recalls being kept up at night by questions like, What is cancer? Why is life like this?
Vincent happened upon the website for the NASA Astrobiology Institute. He realized scientists in the field were being funded to ask the biggest questions, including, Under what conditions does life begin?
Today, she is at the forefront of the young field of astrobiology. In 2019, Vincent led a study that has become an essential guide for other researchers trying to understand how, from a complex mix of chemicals, life could emerge anywhere that basic building blocks exist. The model is called chemical ecosystem selection.
“One of the driving questions is how life started on Earth,” Vincent explains. “That’s really what has been the focus of my research.”
The idea is that the right basic ingredients mixed under the right conditions (perhaps like those found in an ancient hydrothermal vent) can form a “prebiotic soup,” from which a cascade of interactions between ingredients could ultimately set the stage for life.
Within the soup are chemicals — like amino acids, nucleic acid precursors, sources of phosphate, and more — bound to the surfaces of minerals, tumbling around one another, not unlike grains of sand at the bottom of an ancient sea floor. The chemical mixtures are subjected in the lab to changing conditions.
The researchers look for interactions that sustain themselves without additional inputs and, among these, processes that also adapt, evolve, and survive. In the lab, they create mixtures of solutions that are then diluted into others, searching for interactions that persist, despite conditions that might otherwise burn them out.
“This very grandiose, big-picture science is very simple,” Vincent says.
The next step, which the lab is working on now, is to figure out the most essential ingredients. How will they know they have found what they’re searching for? No one knows exactly.
“The only thing we can do is set the standards for what we think will meet the threshold of what is life-like,” she explains. “In terms of understanding fundamentally what is life, what is essential for life, we have no idea because a lot of what happened at the origin of life has been overwritten by evolution.”
Asking these questions, Vincent says, maybe a fundamental part of being human.
“I think it is this existential need that everyone seems to have in some way, to varying degrees, to understand what we are and where we came from.”
Source: University of Wisconsin-Madison