The Fly Brain That Took Over the Internet: A Drosophila Connectome Plays Doom and Trades Bitcoin

The complete digital model of the brain of a male fruit fly (Drosophila) has unexpectedly become September's biggest internet sensation. Users are making it play Minecraft, Doom and Beat Saber while parking cars, trading bitcoin, carving döner and even writing LinkedIn posts on the side.

What it actually is

What we're talking about is a so-called connectome — a complete map of the more than 166,700 neurons that make up the nervous system of an adult male fly. The model, called MaleCNS v1.0, was developed at the HHMI Janelia Research Campus together with Google Research and unveiled earlier this month. It is the first completed connectome of the entire central nervous system of a male — including the central brain, the optic lobes (the analog of the mammalian retina) and the ventral nerve cord (the analog of the spinal cord). Together with the female map, released in 2024 under the name FlyWire, it makes it possible for the first time to compare the neural circuitry of the two sexes in an animal with complex behavior.

The fruit fly is a workhorse of science: it breeds quickly and is undemanding, which makes it a cheap and versatile model organism. A virtual re-creation of its brain promises advances in neurobiology, pharmacology, biotechnology and artificial intelligence.

Memes and a little science

While scientists ponder the possibilities, the internet is having fun. The wave was started by Georgia Institute of Technology graduate student Evan Sinclair Smith: on September 4 he loaded all of the fly's neurons into Minecraft, and within a day the clip had racked up millions of views. Then came the variations — a “stonkfly” trading bitcoin, a fly retiring to a virtual “drosophila paradise,” and entrepreneur Nico Christie's “bi fly,” programmed to be attracted to other males.

But it isn't all jokes. Christie and his colleagues, wanting to lend the endeavor some scientific rigor, found a group of neurons that lets the fly orient itself by rapidly updating synaptic weights rather than activations — in other words, learning continuously on the fly, something today's large language models cannot do.

The connectome's popularity has also sparked ethical debates on Reddit. Here it's worth stressing: MaleCNS v1.0 is merely a digital map of connections, stripped of the biochemistry of a living organism, and there is no question of any sentience or consciousness.

What it's all for

The connectome was conceived from the start as a resource for science: the female map, FlyWire, has already been used in studies of motor control, sensory systems and flies' social behavior. Smith, for his part, hopes that models like these will one day lead to a connectome of the human brain — that's 86 billion neurons, orders of magnitude more. He fantasizes that this could open up new approaches to Alzheimer's disease, or allow human intelligence to travel into space without the “cumbersome meat sack,” that is, without a body. “It says so much about understanding ourselves,” he sums up.

Source: 404 Media