Is it a man or a mouse?

Scientists have a simple recipe for creating a more human-like mouse: just alter its DNA very slightly.

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Now that we’re done with the “ice bucket challenge”, perhaps we should have a conversation about what to do with the money. Do we want, for instance, to create a monkey that thinks more like a man?

Scientists have a simple recipe for creating a more human-like mouse: just alter its DNA very slightly so that one of the proteins it produces is identical to a protein produced by human DNA. The result is interesting. The mouse will think differently, becoming better at solving certain kinds of puzzles.

It might sound a little prosaic but the implications are profound. That’s because the genetic alteration in question is closely associated with speech. It seems that the uniquely human facility for speech and language is closely linked to our brain’s capacity for processing abstract information.

The gene involved is known as FOXP2. Its role in speech was identified more than a decade ago, when it was implicated in the communication problems of a British family. Across three generations, half of the family members were unable to form words properly, put them in the right order, or fully understand speech. Genetic analysis showed that their FOXP2 gene was defective.

Subsequent research strengthened the case for this gene’s association with speech. Researchers first “humanised” the mouse FOXP2 gene so it would create the same proteins as the human version in 2009. The humanised mice sounded different: when threatened, their alarm calls were more complex than those of pure-bred mice. The latest paper in this line of research has shown that mice enhanced with a humanised FOXP2 gene are also a little smarter. The experiments were complex but, put simply, these mice learned more quickly how to find food in a maze.

The FOXP2 gene hosts one of the few significant distinctions between man and chimp. Just two of the 715 amino acids in the FOXP2 protein created by the gene are different. This suggests that the very subtle differences between human and chimp FOXP2 genes might encode much of the gulf in intelligence – a gulf that could conceivably be overcome through genetic engineering. Wouldn’t it be fascinating to see what a chimp could do if its FOXP2 were humanised?

Humanised primate brains would conceivably be very useful for research into the causes of neurological disorders. Researchers have already put human cells into vervet monkeys to aid their research into Parkinson’s disease, for instance. The trouble is, we are heading into uncharted waters. What kinds of thoughts does a humanised monkey think?

A 2011 report by the UK’s Academy of Medical Sciences made it clear we don’t know. “The key question, which cannot at present be answered with any certainty, is whether populating an animal’s brain with human cells could result in that animal developing some elements of human consciousness,” it explained.

If this could be true for mice, how much more so for monkeys? Talking to the BBC, Christopher Shaw, a professor of neurogenetics at King’s College London, put it neatly: “If your parrot says, ‘Who’s a pretty boy then?’ that’s OK . . . If your monkey says it, that’s a very different matter.”

Shaw’s work is part-funded by the Motor Neurone Disease Association, one of the beneficiaries of the ice bucket challenge. As our willingness to freeze our friends demonstrated, we are all keen to help cure disease – and making smart monkeys would no doubt help. Yet, as Shaw implied, we also have to be willing to hold back research when ethical considerations require it. Sometimes, for all the money raised, getting cold feet is the right outcome. 

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article appears in the 24 September 2014 issue of the New Statesman, The cult of Boris