Microbiologist José Penadés stopped in his tracks while out shopping. Stunned, he even asked his companions for an hour to process what had just happened. Google's AI research tool, Co-Scientist, had reached the same conclusion his team had spent a decade working on—in just two days.
Feeling as if the very foundation of research was shaken, Penadés immediately emailed Google:
"You have access to my computer, is that right?"
Google, of course, denied it. So how did Google's AI achieve in 48 hours what took Penadés’ team ten years?
A Decade of Research Solved in Two Days?

superbugs evolve and spread. Their hypothesis? Superbugs might acquire a "tail" from viruses, allowing them to jump across species—much like having a "key" that unlocks new hosts.
This research was highly confidential, unpublished, and known only to the team. Yet, when Penadés prompted Google's Co-Scientist AI with a simplified version of their research question, the AI arrived at the same hypothesis in just 48 hours.
Even more shocking? It proposed four additional hypotheses, one of which the researchers had never considered—and they are now pursuing as a new avenue of study.
Co-Scientist: AI That Thinks Like a Researcher?
Unlike traditional AI tools that summarize and retrieve literature, Google’s Co-Scientist, built on Gemini 2.0, is designed to generate and validate scientific hypotheses—accelerating research far beyond conventional methods.
How does it work? Co-Scientist functions as a multi-agent system, each AI specializing in a different role:
🔹 Generation – Creates initial research hypotheses
🔹 Reflection – Evaluates feasibility and provides feedback
🔹 Ranking – Prioritizes the most promising hypotheses
🔹 Evolution – Iteratively improves hypotheses for scientific rigor
🔹 Proximity – Assesses relevance to existing research
🔹 Meta-Review – Ensures consistency and reliability of findings
By mimicking the scientific process, Co-Scientist drastically reduces the time required for hypothesis generation and validation. What once took years might now take days.

One of Co-Scientist’s most powerful capabilities is its self-evaluation and hypothesis tournament system, designed to refine ideas through AI-driven debate.
🔹 Self-Play for Hypothesis Refinement
Using a self-play mechanism, Co-Scientist generates new hypotheses based on existing ones, then compares and debates them against each other. This iterative process ensures that only the most logically robust hypotheses survive.
🔹 Elo Auto-Evaluation: Ranking Scientific Ideas
Inspired by the Elo rating system used in chess, Co-Scientist automatically scores and ranks competing hypotheses. Factors such as logical consistency, alignment with existing research, and novelty determine which ideas advance.
This self-refining approach explains how Google’s AI derived a decade’s worth of research in just 48 hours—and even proposed new, viable hypotheses that human researchers hadn’t considered.
Real-World Scientific Breakthroughs Powered by Co-Scientist
Can AI accelerate scientific discovery? Co-Scientist has already demonstrated its potential in multiple cutting-edge research areas. Here are a few notable examples:
🔬 Drug Repurposing for Acute Myeloid Leukemia (AML)
Co-Scientist identified existing FDA-approved drugs as potential AML treatments. Lab results confirmed that these drugs effectively suppressed cancer cell survival, offering a promising new treatment avenue.
🧬 Liver Fibrosis Target Discovery
By analyzing epigenetic markers, Co-Scientist proposed a novel therapeutic target for liver fibrosis. When tested in human liver organoids, this target exhibited strong anti-fibrotic effects, paving the way for new treatments.
🦠 Decoding Antimicrobial Resistance (AMR)
Co-Scientist formulated a new hypothesis explaining bacterial gene transfer mechanisms involved in antibiotic resistance. Recent experimental studies confirmed its predictions, aligning with cutting-edge research in microbiology.
As AI-powered research agents like Co-Scientist continue evolving, we may be on the brink of a new era of accelerated scientific discovery.

Can AI revolutionize scientific research? José Penadés has experienced firsthand how AI can accelerate hypothesis generation and validation—a process that once took years, now condensed into days.
Amid concerns about AI replacing human researchers, Penadés offers a different perspective:
I'm in front of something that is spectacular, and I'm very happy to be part of that.
It's like you have the opportunity to be playing a big match - I feel like I'm finally playing a Champions League match with this thing.
Far from replacing scientists, AI is becoming their strongest collaborator—and Co-Scientist is living up to its name. This is just the beginning. What other Co-series innovations might we see next?