Five years ago, Daniel MacArthur set out to build a massive library of human gene sequences—one of the biggest ever. The 60,706 raw sequences, collected from colleagues all over the globe, took up a petabyte of memory. It was the kind of flashy, blockbuster project that would secure MacArthur a coveted spot in one of science’s top three journals, launching his new lab at the Broad Institute into the scientific spotlight. But before all that happened, he did something that counted as an act of radicalism in the world of biology: He put it on the internet.

Posting scientific papers online before peer review—in so-called preprint archives—isn’t a new idea. Physicists have been publishing their work this way, free to the public, for decades. But for biologists, preprints are uncharted territory. And that territory is rapidly expanding as academia and its big-time funders shift toward a culture of openness. As preprints become more popular, they’re throwing the field into a state of uncertainty.

Science usually goes like this: Researcher runs experiment, researcher analyzes data, researcher writes up results. In high school biology, the process stops there. But in real life, that’s when the real slog starts. Researchers submit their results to the most prestigious journal they think might publish them ... and then they wait. If the paper is rejected, they try another journal. Then they wait again. Once they get accepted, they go through a cycle of peer review, responding to critiques from an anonymous group of colleagues. On average, it takes biomedical researchers eight months to go from submission to publication, but sometimes it takes up to three years. All the while, scientific progress—the sequential building of knowledge, based on the work of others—gets held up.

That slow, rigorous process leaves academic publishing houses—including big names like Springer Nature, Wiley, and Elsevier—with control over the flow of scientific knowledge. By selling that knowledge back to universities, academics, and the public in pricey subscriptions and per-article fees, the global industry brings in more than $24 billion in revenue every year. But since the early 2000s, scientists and powerful funders like the Gates Foundation, the Ford Foundation, and the Wellcome Trust have championed alternatives to subscription publishing. Grant-givers want to stretch the public impact of their research dollars, which means knocking down pricey paywalls. And researchers want to break out of the brand-name journal merry-go-round, whose incentives, they believe, are distorting the quality of modern science.

“This is a tipping point in biology. It’s a cultural choice, not a technological question.” Stephen Quake

Preprints could solve these issues by decoupling distribution of results from their certification via peer review. But publishers and some scientists worry preprints will only further dilute the research literature and endanger fields already struggling with reproducibility failures. And since preprints also threaten to dilute revenues at academic publishing houses, there’s more than just scientific integrity at stake.

Daniel MacArthur, like most scientists trying out the preprint scheme, didn’t totally abandon the traditional scientific publication track. His human exome reference library was eventually published in Nature, and would go on to be cited more than 800 times. But because he posted both the dataset and the preprint explaining it more than nine months before the peer-reviewed version came out, other scientists didn’t have to wait to start using his data. Between October 2015 and August 2016, scientists viewed his newly compiled exome data 3 million times and downloaded the preprint more than 18,000 times. Together, they helped researchers launch new investigations into the genetic factors underlying diseases like schizophrenia, Alzheimer’s, and cancer.

This, then, is the two-fold promise of preprints: Scientists get to demonstrate their scholarly contributions to potential funders while their manuscripts are being peer-reviewed for publication. And at the same time, the scientific community gets to see that work months or even years before they would otherwise. Just how quickly could preprints speed up scientific discovery? According to Stanford bioengineer Stephen Quake, if one preprint inspired the work of just two other people, biologists would see a five-fold acceleration in scientific progress within a decade.