Unlocking History with Geology and Genetics

Fatima Husain SM ’18 grew up in the heart of the Midwest, surrounded by agriculture. “Every time you left your home, you saw fields of corn and soybeans. And it was really quite beautiful,” she says. During elementary school, she developed her own love of gardening and cultivated a small plot in her family’s backyard.

“Having the freedom to make a mess, experiment, and see things grow was very impactful,” says Husain, a fourth-year doctoral candidate in the MIT Department of Earth, Atmospheric and Planetary Sciences (EAPS) and a Hugh Hampton Young Fellow. This experimentation in the garden was the seed that blossomed into her fascination with science. “When you think about gardening and agriculture in Iowa,” she says, “you think about soil and its origins, which led me to geology and geochemistry and all these interdisciplinary fields that play a role in the Earth sciences.”

Husain has maintained that scientific curiosity throughout her academic career. As a graduate student in EAPS’ Program in Geology, Geochemistry, and Geobiology, she studies the fossil and genetic records of ancient and modern life forms to better understand the history of life on Earth. She says, “Twenty years ago, I was a stoked kid working with topsoil in Iowa. Now, I get to work with ancient dirt and sediments to better understand Earth and life’s past.” 

Sharing Science

Though Husain loved her environmental science class in high school, when she enrolled at Brown University, she wasn’t sure which STEM major to pursue. Then, a guest lecture in her first-year biology course dispelled any uncertainty. “A professor walked on stage and introduced himself as a biogeochemist, and after that, everything just clicked,” she says. Within weeks of that fateful lecture, she had declared a major in geochemistry. “I’ve never looked back,” she says.

She then immersed herself in her Earth science classes, which applied the core science disciplines she studied to topics such as the oceans, weather and climate, and water quality. “I gained a sincere appreciation for the excellent teaching and writing that helped me access the world of the geosciences,” she says, “And that helped me realize the value in communicating science clearly.”

To hone her writing skills, Husain took nonfiction writing classes as her electives and joined one of the school newspapers. There, she took on the role of science writer and editor. As she neared graduation, she knew that she would eventually pursue geochemistry at the graduate level, but first she wanted to focus on journalism and writing. She reasoned that, if she could formally learn the fundamentals of science writing and reporting, then “I could more effectively share all the science I learned after that point,” she says. With the support of her undergraduate professors, she decided to apply to MIT’s Graduate Program in Science Writing, one of the only such programs in the country.

The program refined Husain’s writing skills and paved the way for her to pursue science journalism opportunities across a variety of media, including print, video, podcasting, and radio. She worked as a writing intern for MIT News during this time, and has written a number of MIT News articles while at MIT. After graduating, she served as a Curiosity Correspondent for the MIT-Nord Anglia Education Collaboration based at the MIT Museum. In that role, she says, “I worked on communicating the amazing science happening here at MIT to K-12 students around the world via educational videos.” Since beginning her PhD studies, Husain has transitioned to a new role in the collaboration—hosting a monthly webinar series called MIT Abstracts, which connects MIT researchers and experts with an international audience of middle schoolers.

Along the way, Husain has also worked as a reporter and managing producer for a Rhode Island-based sustainability science radio show called Possibly. In 2019, she founded a podcast with her colleagues called BIOmarkers, which serves as an oral history project for the discipline of organic geochemistry.

Acquiring the “Biggest Tool Set” Possible

After completing her master’s thesis, Husain began to return to her roots in geochemistry. She says, “At some point, when I was interviewing other scientists and they described their experiments, I’d miss being in the lab myself. That feeling helped me realize the time was right to get back into research.” Husain chose to stay at MIT for her PhD. “I couldn’t resist the opportunity to continue working on challenging, interdisciplinary problems within such an exciting environment,” she says. “There really is no other place quite like it.”

She joined the lab group of Roger Summons, the Schlumberger Professor of Geobiology. For her first project as a research assistant, Husain helped then-postdoc Ainara Sistiaga reconstruct the environment of Tanzania’s Olduvai Gorge 1.7 million years into the past, using molecule-scale fossils preserved in archeological sediments. Part of Africa’s Great Rift Valley, the site preserves evidence of ancient hominin tools and activities. The research team’s findings were later published in published in PNAS.

Under the mentorship of her advisors, Gregory Fournier, an associate professor of geobiology, and Summons, Husain studies both the fossil record and the genetic records of organisms alive today to answer fundamental questions about life’s evolution on Earth. “The farther back into Earth’s history we go, the fewer complete records we have,” Husain says, “To answer the questions that arise, I hope to employ the biggest tool set I can.”

Currently, Husain investigates the biomarkers of microbes living in Antarctic biofilms, which she hopes will provide hints about the types of places where the ancestors of complex life sheltered during global glaciation events through Earth’s Cryogenian period, which stretched between 720 to 635 million years ago. To do this, Husain applies techniques from chemistry, such as chromatography and mass spectrometry, to isolate and study microbial lipids, the precursors of molecular fossils preserved in the geologic record.

Husain also uses “molecular clocks,” tools that employ the genetic sequences of living organisms to estimate when in evolutionary time different species diverged, to better understand how long ago aerobic respiration arose on Earth. Using the growing databases of publicly available gene sequences, Husain says it’s possible to track the histories of metabolisms that arose billions of years ago in Earth’s past. Much of her research can also be applied to astrobiology, the study of potential life elsewhere in the universe.

As a PhD student, Husain has also had the opportunity to serve as teaching assistant for 12.885 (Science, Politics, and Environmental Policy) for two semesters. In that role, she says, “My goal is to help students improve their writing skills so that they are equipped to successfully communicate about important issues in science and policy in the future.”

Looking ahead, Husain hopes to continue applying both her science and communication skills to challenging problems related to Earth and the environment. Along the way, she knows that she wants to share the opportunities that she had with others. “Whichever form it takes,” she says, “I hope to play a role in cultivating the same types of supportive environments which have led me here.”  

This story was originally published by MIT News. 

Photo: Gretchen Ertl