This is not a fly uploaded to a computer

Last week, a few posts about a so-called virtual “embodied fly” tore through X, boosted by AI hype accounts and excited commenters who didn’t seem to understand what it was they were excited about.

This is not a fly uploaded to a computer

A lot of buzz, but not much evidence.

This is not a fly uploaded to a computer

A lot of buzz, but not much evidence.

The videos came from San Francisco-based Eon Systems, which says it’s working toward “digital human intelligence” and claims it wants to build a full digital emulation of a mouse brain within the next two years — a timeline that is, to put it generously, ambitious. Cofounder Alexander Wissner-Gross shared the original clip publicly, calling it the “world’s first embodiment of a whole-brain emulation that produces multiple behaviors” and hinting at an impending technological singularity. CEO Michael Andregg posted a different cut, describing it as a “real uploaded animal.”

And that was it for proof: no detailed methods, no scientific paper, no independent verification, just videos of what looks like a digital fly walking around, eating, and rubbing its legs together.

We've uploaded a fruit fly. We took the @FlyWireNews connectome of the fruit fly brain, applied a simple neuron model (@Philip_Shiu Nature 2024) and used it to control a MuJoCo physics-simulated body, closing the loop from neural activation to action.

— Michael Andregg (@michaelandregg) March 8, 2026

A few things I want to… pic.twitter.com/Qnlu3INs33

AI-related accounts on X and Reddit amplified the clips and repeated the captions as fact. Predictable drive-by endorsements from the likes of Elon Musk (“wow”), Bryan Johnson (“this is amazing”), and Peter Diamandis (“this is a living being…online”) added fuel to the fire. Then the content farms moved in, repackaged the whole thing as “news” celebrating the first-ever brain upload and asking “Are humans next?” (yes, they also referenced The Matrix, and spoiler: We are not next).

“This is, in our view, a real uploaded animal.”

The internet was abuzz. The evidence was still two short videos on X. If you’re going to tell the world you’ve just hit what would be one of the most significant scientific milestones in human history, you better come with receipts.

Andregg attempted to provide some clarity on X in a thread that was part grab bag of caveats, part vaguely-described scientific terms, and part concrete-sounding numbers like “91% behavior accuracy.” I’ve sat with that metric for a while, and I still don’t really know what it’s supposed to mean, and I spent a good chunk of my master’s degree studying animal behavior. Nevertheless, he insisted that “this is, in our view, a real uploaded animal.”

I sent Andregg a message on LinkedIn asking for more details. He replied with a link to a blog post Eon had just published titled “How the Eon Team Produced a Virtual Embodied Fly.” It wasn’t a scientific paper, but it was something, I guess.

For the experts The Verge spoke to, that blog wasn’t nearly enough, but it trod a much more cautious line than the posts on X, in so much as it doesn’t say “this is a real fly.” Shahab Bakhtiari, a professor leading the systems neuroscience and AI lab at the University of Montreal, said that while initial posts “obscured critical” details about the work, the new blog provided more context. “But it arrived a bit late, and remains insufficient to fully validate the claims,” he said. He would have expected a detailed technical report that includes details on things like software, code, and simulation environments that would let other scientists reproduce and evaluate the work.

Alexander Bates, a research fellow in neurobiology at Harvard Medical School studying fly brains, echoed Bakhtiari. He said the group “under-delivered” and that while the blog provided more details on what the team did — they stitched together existing large-scale projects like a detailed map of a fly’s brain, a physical simulation of a fly’s body, and models simulating how these interact in a virtual environment — “for a claim of this magnitude, I would expect something that should spell out the whole approach in specifics.”

Bates also said the virtual fly’s behavior should be evaluated against real data and “clearly defined metrics,” adding that the 91 percent figure was still not explained in the blog post. “Also, the fly does not fly.”

Bates told The Verge he understands that “strong framing and hype can matter for fundraising,” but stressed Eon’s claim of a “real uploaded animal” isn’t credible. Aran Nayebi, a professor of machine learning at Carnegie Mellon University, said that the group was “not even close” to capturing the full brain of the fly, showing connections between cells but not crucial details like neurotransmitters or how strong the connections between different nerve cells are. The motor system isn’t a “true upload” either, he said. “We are not even faithfully simulating its brain in silico.”

Fine, let’s say Eon actually did it. It copied the fly’s brain perfectly. The whole thing. Every last part. Do we have a digital fly now?

Yes. No. Maybe. I don’t know, and you probably don’t either. Neither does Eon. The blog conveniently glossed over the weighty definitional questions at the core of the upload claim: What, exactly, counts as a fly? When we think of flies, we don’t think of a bunch of behaviors or neural connections. We think of, well, a fly. Is it enough to reproduce a few fly-like behaviors in a simulation? Does a fully mapped brain in a virtual vat count? Or does “fly” mean the whole, messy biological package — a body, cells, metabolism, and whatever counts as “memory” or learned experience over the course of its life?

And that’s the easy version of the problem. The thing on the screen isn’t obviously a fly at all. It’s a composite of the neural wiring, programming, and other information stitched together from multiple different animals. This is useful when modeling, but precisely what organism can we meaningfully claim has been uploaded in this case? Technically speaking, it’s also a copy, not an upload, which comes with obvious and profound implications the hype conveniently skips over: You could make two, or 10, or 10,000 of the “same” fly. What then?

Normally, I wouldn’t expect a startup to solve a major metaphysical problem — philosophers have been squabbling over that one for centuries — but they’re the ones saying they’ve got a “real uploaded animal.”

The experts I spoke to weren’t even convinced the term makes sense. Bakhtiari said it’s still very much an “open question” as to whether a “real uploaded animal” is even possible. Jonathan Birch, a philosopher at the London School of Economics, was blunter: “I don’t think we should ever say ‘uploaded animal,’” he said. What Eon is aiming for, he said, is “whole-brain emulation,” leaving the rest of the animal behind.

“…this fly is conscious in a limited sense, it can smell, see, taste, etc.”

That biology is important to behavior, said Tom McClelland, a philosopher at the University of Cambridge. “So at best they’ve uploaded some of the fly’s mind and thereby uploaded some of the fly.”

With some time behind his viral post, I asked Andregg if he stood by his claim. “Yes,” he told me. In fact, he went further: “We [the research group and its academic collaborators] think this fly is conscious in a limited sense, it can smell, see, taste, etc.” (I will absolutely not be going into the whole consciousness thing.) He described the system as a kind of “MVP,” minimum viable product, of an uploaded animal, one with “lots of limitations.” I don’t quite know how to picture a minimum viable fly. It’s a fly, not an app. MVP is tech startup speak, not science.

When I went back to Andregg a second time — this time after speaking with experts and relaying their criticism — he still stood by the original claim, but with even more caveats. He conceded the work “isn’t a perfect replica of a