Poison Control: Could Humans Become Venomous?

Poison Ivy. Spider-Man 2099. Omega Red. These toxic comic book characters use poison-based attacks to defeat their opponents. But can mere mortals be capable of the same deadly skill? Scientists think so, as new research has revealed that humans have the genetic bedrock needed to spit venom!

Toxicity is Written in Our Genes

Scientists from the Okinawa Institute of Science and Technology Graduate University (OIST) and the Australian National University recently conducted a study to learn how venom glands evolve in animals .

Countless creatures spanning multiple species produce oral venom, including snakes, spiders, and even shrews. But while most mammals—including people—aren’t venomous, the study found that any animal with salivary glands has the potential to become toxic.

The team made this discovery by studying venom-producing tissue in Taiwan habu vipers. They focused on 3,000 genes that work alongside venomous ones. These “cooperating” genes protect cells from stress and manage protein folding and modification.

Scientists found the same genes and molecular mechanisms in mammals, including mice, dogs, and even humans!

“While many snakes employ an oral venom system for securing prey, there are also mammals, such as shrews and solenodons, that have evolved oral venom systems (based on salivary glands) for prey capture or defense. Therefore, the overall conservation of metavenom network expression, as well as preservation of the metavenom network module, suggests that salivary glands in mammals and venom glands in snakes share a functional core that was present in their common ancestor. Using this common molecular foundation as a starting point, snakes diversified their venom systems by recruiting a diverse array of toxins, while mammals developed less complex venom systems with high similarity to saliva. Developing similar traits using common molecular building blocks is the hallmark of parallelism,” the study, published in PNAS, states.

Will People Become Poisonous?

Many mammals have evolved to make oral venom, including platypuses, vampire bats, and slow lorises. But while humans produce essential proteins present in many venomous systems, evolution has yet to lead us down a poisonous path.

The animals that have evolved to produce venom did so to overpower prey or defend themselves. The way venom evolves directly correlates to how animals live. Humans, on the other hand, have developed the necessary tools and skills to feed and defend ourselves without requiring venom.

Surprisingly, experiments conducted in the 1980s found that male mice can produce proteins in their saliva that are deadly to rats. So, although highly unlikely, humans could evolve to create venom under the right ecological conditions.