Every week in Fact/Fiction, The Big Issue examines spurious claims, questionable studies or debatable stories from the press to determine whether they are fact or fiction. This week Liam Geraghty looks at reports into a study claiming humans could develop venomous saliva.
How it was told
Spend a bit of time on social media nowadays and you could be forgiven for thinking humanity needs a little help with toxicity.
But rather than just spilling out bile online, people could soon be developing venom in real life if stories in the press were to be believed last week.
While venom is probably more closely associated with snakes than humans, a study from Japan’s Okinawa Institute of Science and Technology Graduate University and the Australian National University suggested otherwise.
The study, published in the PNAS scientific journal, attracted plenty of coverage.
Mail Online led the way with the headline: “Toxic people could become a reality! Humans could be on an evolutionary path to developing venomous SALIVA, study claims”.
That pun sparked something of a pattern. The Daily Telegraph took a similar approach with its effort: “Toxic personality? You could evolve the venom to go with that”.
The Independent ran with the headline: “Venomous people could become a reality, scientists say” while LadBible’s effort was similar, opting for: “Humans could become venomous in the future, study claims”.
Wales Online also covered the story. It ran: “Human saliva has potential to evolve into venom, say scientists”.
Sky News broadened its approach to other creatures with: “Mice (and even people) really could have the ability to become toxic, snake venom scientists say”.
OK, we’ll bite. Is there any truth to the stories?
Perhaps unbelievably, the stories are true. However, it must be said that the claim humanity is on the evolutionary path to developing venom is slightly questionable.
Researchers described that possibility as “very unlikely” – an opinion that was mentioned largely at the bottom of the stories that included it.
The scientific breakthrough here is that scientists found the genetic foundation required for oral venom to evolve is present in both reptiles and mammals. They also discovered the first concrete evidence of an underlying molecular link between venom glands in snakes and saliva glands in mammals.
To do this, the team searched for genes that work alongside and interact strongly with the venom genes, using venom glands collected from the Taiwan habu snake – a pit viper found in Asia – as a base. They identified around 3,000 ‘co-operating’ genes and discovered they protected cells from stress caused by producing lots of proteins.
The researchers then looked at the genomes of other creatures across the animal kingdom, including mammals like dogs, chimpanzees and humans, and found they contained their own versions of these genes.
This led to the realisation that the genes in mammals’ salivary glands had a similar pattern of activity to the snake venom glands. Scientists believe the salivary glands in mammals and venom glands in snakes share an ancient functional core that has been maintained since the two lineages split hundreds of millions of years ago.
So while the stories that acknowledge the potential for humans to create venom are true, articles like the one from Mail Online are getting slightly ahead of themselves with assertions that humans could be on the evolutionary path to venomous saliva. As Live Science’s version of the story reports – under the headline “Could humans ever be venomous?” – it is unlikely that humans would evolve to produce venom.
Dr Ronald Jenner, a venom researcher at the Natural History Museum in London who was not involved in the research, told Live Science, “humans’ currently successful strategies of acquiring food and choosing mates” mean there is little need for venom. He stated that venom is traditionally used for defence or subduing prey.
So while, sadly, the prospect of snake-like superpowers might be off the table, at least for a few generations, the scientific breakthrough instead shifts to the potential for developing medicines and other scientific applications.
On the whole, the media outlets did a good job on this story, but it is worth reading until the end of the stories before getting too excited about the prospect of big changes in humanity’s immediate future.