Using big data for good

A photogenic green-eyed Russian Blue named Petra might just be the world’s most sequenced cat. Petra was rescued from an animal shelter in Reno, Nevada, by Charlie Lieu, MBA ’05, SM ’05, a data whiz, serial entrepreneur, investor, and cofounder of Darwin’s Ark, a community science nonprofit focused on pet genetics. Since becoming Lieu’s furry friend, Petra has had her DNA fully sequenced six times and extracted nearly 60 times, all in the name of science. 

Petra is just one of more than 67,000 cats and dogs whose information has been entered by their human caretakers into the Darwin’s Ark databases, which the organization’s researchers and collaborators are using to try to better understand pet health and behavior. Since its founding in 2018, Darwin’s Ark has helped researchers probe everything from cancer to sociability to whether or not trainability is inherited, allowing them to debunk stereotypes about dog breeds and investigate similarities between complex diseases in humans and animals. 

DNA testing for dogs  is common at this point, with multiple for-profit companies offering to break down your pet’s breed background for a fee. But Lieu and her Darwin’s Ark cofounder, Elinor K. Karlsson, wanted to go beyond offering individualized DNA reports and invite humans to participate in surveys about how their pets play and socialize, and even whether or not they get the zoomies right after using the litter box. This approach pairs DNA with vast amounts of behavioral data collected by the people who know these animals best, thus harnessing the power of humans’ love for their pets to advance cutting-­edge science. 

In the process, Darwin’s Ark has solved a problem that is often an obstacle in human medicine: how to get the enormous quantity of data needed to actually understand, and eventually solve, medical problems. 

It was this problem that initially interested Lieu, who is chief of research operations for Darwin’s Ark, in pet genetics. Lieu spent some of the early, formative years of her career working on the Human Genome Project at the Broad Institute, where she first collaborated with Karlsson—and remembers sleeping under her desk in the late ’90s while “babysitting” servers in case they needed to be rebooted in the middle of the night. For many years, her North Star was cancer research: Her mom had died of cancer, “nearly everyone” on her mom’s side of the family got cancer at some point, and Lieu herself had her first of multiple tumors removed at age 17. 

Researchers used data collected by Darwin’s Ark to show that just 9% of variations in dog behavior can be predicted by breed.

Throughout her nearly 30 years working with the Broad and other initiatives related to such research, Lieu has often felt struck by how difficult it is to study complex diseases like cancer. Gathering extensive data about people while maintaining their legally mandated privacy can be tricky, as is getting them to participate in strict protocols over the course of many years (an issue she has also experienced from the other side, since she is enrolled in multiple longitudinal studies).

About a decade ago, Lieu reconnected with Karlsson, who had moved on from the Human Genome Project to work on animal genetics and was engaging with pet owners in her research. Karlsson bemoaned how hard it was to get the large-scale genomic data needed to advance scientific understanding, and something clicked. What if they could tap into Lieu’s expertise with big data platforms and her experience starting nonprofits to collect genomic data from pets as a proxy for understanding complex diseases and behavior? “We talked a lot about how we [might] enable a platform that could help us collect the right kinds of data at the level that’s necessary in order to do the kinds of science that the world needs,” Lieu says. That might be hard with humans, but “everybody wants to talk about their dogs and cats, right?”

Thus Darwin’s Ark was born. Initially it focused on dogs, and using its data, Karlsson and a team from the Broad and elsewhere were able to demonstrate that just 9% of variations in behavior can be predicted by breed—much less than people might think. Lieu hopes the finding will help certain much-­maligned breeds such as pit bulls, which tend to be adopted at lower rates and sometimes are even put down on the basis of faulty assumptions about their behavior. 

But the work Darwin’s Ark is doing isn’t just helping pets—it could benefit humans, too, as researchers increasingly probe the links between human and animal cancers. 

“We were involved in some early dog work in cancer, where we collaborated with another group to understand whether or not you could take a blood draw and figure out whether or not the animal has cancer,” says Lieu. “Turns out you could. And in the last couple of years, an FDA-approved test has been available for humans to figure out whether or not you have lung cancer. All that work started in dogs, so you could start to see the power of doing something in animals that then impacts human health.”

Darwin’s Ark broadened its focus to cats in 2024, and while it’s too soon for any results, even the research methods are proving interesting. The usual way to extract DNA from a living animal is by swabbing the inside of a cheek. Dogs don’t mind the process, but cats are not as amenable to having things stuck in their mouths. Nor do cats appreciate having hairs plucked out with their follicles, another potential source of DNA for sequencing. So Chad Nusbaum, PhD ’91, another Human Genome Project colleague that Lieu recruited, helped the Darwin’s Ark team figure out how to effectively extract DNA from fur or hair that has been shed—a big breakthrough for the field. (This means, in practice, that cats’ DNA is collected by brushing their fur. Now the cats “not only don’t mind sample collection—some of them really enjoy it,” Nusbaum says with a laugh.) 

That’s good for cats, but it could also have far-reaching implications in the world of conservation, where obtaining DNA from endangered or sensitive animals via blood or skin samples can be prohibitively difficult or distressing to the animals. Being able to rely instead on a few strands of naturally shed hair could unlock new frontiers for conservationists working with sensitive species.

The knowledge that progress on such crucial issues could come from inside or outside the organization was what led Lieu and Karlsson to structure Darwin’s Ark as a nonprofit and make its data available for free to researchers outside commercial settings. While it already periodically shares its sequence data in various public repositories, those repositories are managed by different entities, making it more difficult for scientists to use the information. So researchers must often write in, explain what they’re trying to do, and put in a custom request.Darwin’s Ark just got a grant that will allow it to begin building a public portal for the data, making it far easier for researchers to access, match, and use.

“Our hope is that we would be able to create a data set that scientists around the world would be able to leverage to elucidate whatever it is that they’re doing,” Lieu says. “Whether you’re a cancer scientist or a neurological scientist or an immunology-focused scientist, any number of complex disease areas could be helped by having very massive data sets.”

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For Lieu, Darwin’s Ark is but the latest line in a long and wide-ranging résumé that includes stints at Amazon and NASA. “The thread that ties it all together is big data,” she says.

After living and breathing data in her work on the Human Genome Project, Lieu tackled a very different big data challenge at Amazon on a team that collected data on warehouse fulfillment. Drawing on her biological sciences background, she developed an evolutionary algorithm for outbound logistics that made it possible—without constantly analyzing the data—to dynamically optimize storage and dramatically lower fulfillment costs.  The founder or cofounder of at least a dozen ventures to date, she built on her experience at Amazon with her most recent startup, a logistics company called AirTerra that helps e-commerce retailers streamline delivery by bringing together highly fragmented last-mile shipping providers under one umbrella. Officially founded in 2020, it quickly achieved unicorn status and was acquired by the fashion company American Eagle Outfitters in 2021. While Lieu chalks some of that success up to luck (“You start a shipping and logistics organization in the pandemic—of course you’re going to get acquired”), her cofounder Brent Beabout, MBA ’02, is quick to point to the skill and work ethic that made her “luck” possible. 

Besides being “highly collaborative” and “super knowledgeable,” Lieu gave her all in a way that set her apart, according to Beabout. “She is a passionate person,” he says. “I’ve never seen a person that worked as many hours as Charlie did … I don’t think she ever slept.”

Lieu jokes that she’s in a “midlife crisis” as she sorts out what to do next, because there’s so much she could do. So she’s looking for the “biggest thing” she can do for the world.

Though Lieu has made out well as an entrepreneur, she grew up “well below the poverty line.” Both those experiences shaped the kind of investor she’s become: one who is distinctly interested in helping other entrepreneurs confront barriers. “I wanted to look back on all the obstacles that I had faced coming up,” she says. “Not just as a woman, not just as a person of color, but [also] the economic barriers of not having the network, not being able to access other people who have been successful, not even understanding the basics of financial markets.” To that end, she’s spent much of her career trying to give back through mentorship and direct investment in ventures started by founders from underrepresented backgrounds.

Her passion for social causes doesn’t end there. Lieu has also volunteered with her local trails association and served on a wide range of boards near her home in the Seattle area. In the mid 2010s, an outdoors-focused organization where she was on the board came under fire for having given a platform to a rock climber who had been credibly accused of sexual assault. As a climber herself, Lieu had assumed that sexual assault wasn’t a major problem in those circles—but, being data-minded as always, she came up with a plan to conduct a survey about the issue while protecting respondents’ anonymity.

That survey grew into SafeOutside, a grassroots movement focusing on combating sexual assault in the outdoors community. After parsing the data—and realizing just how widespread the problem was—Lieu spent years interviewing individual survivors about their experiences and eventually partnered with Alpinist magazine to publicize and share the results of the survey. Beyond sparking much-needed conversation, the initiative turned out to be instrumental in getting Charlie Barrett, a once-celebrated professional climber, put behind bars. He is now serving a life sentence after his conviction for repeatedly sexually assaulting a female climber at Yosemite National Park. Three additional women testified at his trial that they had also been sexually assaulted by Barrett.

Katie Ives, the editor Lieu worked with on the project at Alpinist, remembers being impressed by Lieu’s “sense of caring and compassion and her determination to amplify the voices of people who have been marginalized by history or by the climbing community.” She describes Lieu as a person “whose life is very much driven by a sense of ethical purpose.”

At first Lieu worked on SafeOutside quietly; fearing professional repercussions, she asked that her name be omitted or mentioned only in passing in reporting on the project. She reasoned that the subject made people uncomfortable. But in early 2025, she began to discuss it more openly. “That’s actually part of the problem, right? People who have status refusing to talk about an issue that’s so prevalent,” she says. Today, she’s more outspoken than ever and wants to encourage others with any kind of social clout to speak up as well.

In some ways, this reevaluation of her approach reflects the crossroads at which Lieu now finds herself. After years of starting new ventures, serving on seemingly endless boards, and typically getting by on three to five hours of sleep a night, she’s finally taking a step back: saying no to board positions, pressing pause on new venture ideas, and even hiring a team that allows her to pass off more of her Darwin’s Ark work to other people. Lieu has always liked—and is especially good at—shepherding new companies through the startup and early growth stages. So she’s been recruiting a new leadership team to take over the reins as Darwin’s Ark prepares for its next phase of growth. She’s aiming to step away from day-to-day operations this spring and will remain a board member and active advisor—and jokes that she’s in a sort of “midlife crisis” at age 50 as she tries to sort out what to do next, because there’s so much she could do.

In this new chapter, Lieu says, she’s trying to identify the “biggest thing” she can be doing for the world in this moment. For now, she’s leaning toward working on economic inequality and reproductive health access, which she says are inextricably tied not only to each other but also to ecology and sustainability.

If her past endeavors—from promoting the well-being of cats to pursuing cures for cancer—are any indication, any cause she devotes herself to will be lucky to have her. “She’s just somebody who gets things done,” says Ives.  

And all the data on Lieu says that’s not going to change.