Is it an ADHDaptation?

Apparently easy access to Ritalin isn’t the only benefit of ADHD. I read a report on a study looked at a mutation that causes impulsive behavior linked to ADHD in Kenyan nomads. The study, in which NU Ph.D. student Dan Eisenberg took part, found that carriers were way more ripped than those lacking the mutation. Researchers surmised that the mutation tended to make carriers more spontaneous and meaner, personality traits which are apparently great for moving to the front of the Kenyan cafeteria line.

While anything concerning ways to get ripped will usually tend to catch my eye, I’ve always found genetic studies like these interesting because they show how some common traits which seem so adverse in today’s society actually possess adaptive value in some habitats. A classic example of this is the gene for sickle cell, which if heterozygous, provides resistance against malaria. However, in areas where malaria isn’t common, being homozygous (and thus affected by the trait) trait really blows, as it drastically reduces lifespan and causes a host of other really lousy effects. Yet, due to its heterozygous advantage, the gene prevails in frequency in malaria-infested regions such as sub-Saharan Africa, the Mediterranean, and India. Fun.

Another sad example might include Huntington’s disease, an autosomal dominant trait that leads to death by middle age or so. I’ve heard that the frequency of the Huntington’s disease gene increased pretty steadily in the last century. The popular assumption is that carriers, knowing that their lives are short, tend to engage in riskier lifestyles which could potentially produce more offspring. However, the gene might somehow increase fitness in some other way. Those of you “House” fans who know about Thirteen might have some idea of what I’m getting at…

Hope this post wasn’t too speculative, but what’s a mind to do on a boring summer day? By the way, here’s the ADHD report on New Scientist:

http://www.newscientist.com/channel/being-human/dn14100-did-hyperactivity-evolve-as-a-survival-aid-for-nomads.html