Recently, The Independent (UK) ran a story that suggested climate change could lead to the extinction of a particular kind of person in the islands of the North Atlantic, the ginger. The article interviews the managing director of the ScotlandsDNA project, Alistair Moffat, who suggests gingers in Scotland may fade into the mists of Scottish myth and history, and it's climate change's fault.
As socio-political footballs go, climate change is at World Cup-level. But this seemed like a new one.
The basic argument is that way back when, as people moved into cooler, cloudier climates, the ginger gene was selected for because it allowed them to absorb more sunlight and create more vital Vitamin D. Thus, so the thinking goes, if climate change leads to a warmer environment, that will somehow reverse the effect and ostensibly result in fewer gingers.
In other words, Moffat is arguing that environmental pressures determine gene expression/selection. Which doesn't seem quite right.
Thing the First
Genes like the ginger gene are the result of random mutations passed on by the mother and the father. If those genes persist, that doesn't necessarily mean they will or won't be expressed — you could be a carrier of the gene but not be ginger yourself. People expressing ginger genes in cloudier, cooler climates may be more likely to thrive in such a climate because they'll absorb more sunlight and make more Vitamin D, meaning they'll be more likely to pass on those recessive genes. But the climate just provides an environment for those genes to be successful, it doesn't determine the mutation itself. (Someone correct me if I'm wrong here, and I'll add your comment below this paragraph.)
Thing the Second
The article refers to the managing director as Dr. Alistair Moffat. However, if you go to the ScotlandsDNA page, that's not quite the case. (He's the first guy on the far left with the beard — click his head and get his profile.) First, Moffat doesn't have a medical degree or a Ph.D; he has an MA and an M.Phil, writes about the history of Scotland, and has directed the Edinburgh Fringe Festival — laudable accolades all, but he's not a geneticist. (For the record, neither am I.) So the article is misleading when it gives him the honorific of Dr., which suggests he's speaking from a position of expertise on the issue. He's not. The article doesn't interview the three other scientists from ScotlandsDNA that do study genetics.
Thing the Third
There's a logical fallacy at play here. In fancy-talk, it's called denying the antecedent, and looks something like:
If P then Q. Not P. Therefore Not Q.
The structure of the argument, then, would be:
If a cool, cloudy climate, then there will be gingers. Not a cool, cloudy climate. Therefore, no gingers.
That doesn't logically work, because even if the premises are true, that doesn't necessarily mean the conclusion follows.
- If the neighbor's samoyed is outside, then my beagle will bay. The neighbor's samoyed is not outside, so my beagle shouldn't be baying — but he just did at the air horn remix of A-Ha's "Take On Me."
- If it rains then the basil on my deck will be wet. It isn't raining outside, but my basil is still wet because I watered it.
The ginger gene was already present when humans moved into the cloudier climes of the highlands; the cloudier climes didn't create the ginger gene, and if the highlands get a little more sun or warmth, that shouldn't have any impact on the gene's expression. First, it would mean all the people who carry the ginger gene would have to stop knocking boots. Will that ever happen?
Second, just look at some of the warmer, sunnier places where ginger people have migrated to, like North America, or Australia. Mexican light middleweight boxer Canelo Alvarez gets his nickname because of his red hair (canela means cinnamon).
And no matter how much the climate changes in Scotland, it most likely will never be as sunny and warm as Australia (sorry Scotland). Yet no matter how sunny it gets in Australia, gingers still persist there.
It's always worth double-checking the facts of an article, especially when newspapers can't be bothered to do it themselves. It's it's also probably worth getting a handle on how genes are actually expressed so you don't fall for scare-mongering articles that use climate change to put the whammy on you. Last, a little logic can go a long way.
Edit: GoodTimeGirl notes in the comments below that this isn't Alistair Moffat's first rodeo with misguided or misrepresentative science. Maybe he should stick to the Fringe Festival.
Second Edit: It seems we here at the ODeck weren't the only ones put off by Moffat's assertions; yesterday The Telegraph ran a similar critique of Moffat's interview (published the same day as this piece), and it's already made its way into Wikipedia lore.