The BBC News has an article reporting that scientists have found evidence to suggest that human evolution is “speeding up.” Scare quotes are used for speeding up in the title of the article for good reason: it’s a reckless remark that can’t be proffered with a straight face. The study on which the article is based
looked specifically at genetic variations called “single nucleotide polymorphisms,” or SNPs. These are single-point mutations, or changes, in the genetic sequence of DNA on chromosomes.
If the mutation is advantageous then it will spread rapidly in the population, along with DNA on either side of the mutation.
It’s unclear to me whether it’s fair to conclude that evidence of a few changes in genetic sequence is tantamount to evolutionary change on the order of species change, which the article never states. Is there a term that describes minor genetic changes without meaningful change in the species? Put another way, isn’t a wide range of genetic variation within the species pretty normal without being evolutionary?
Researchers found evidence of recent selection in 7% of all human genes, including lighter skin and blue eyes in northern Europe and partial resistance to diseases, such as malaria, among some African populations.
This makes me wonder if the usual four mechanisms influencing evolution — natural selection, mutation, random genetic drift, and gene flow — shouldn’t be amended to include cultural election in the case of culturally preferred attributes such as skin type and eye color. (Nope, no suggestion of cultural bias or racial preference there. Move along.)
Also, if I’m not mistaken, when human evolution is discussed by regular folks without specialized training in genetics, the usual context is science fiction and the mode of evolution is either cultural (evolved minds) or biological (evolved bodies) or both. These are wildly divergent from a more narrowly defined science of genetic evolution, which apparently considers even modest change or variation evolutionary.
Without providing suitable context for the science and disclaiming the obvious associations with science fiction, the article invites credulous readers to infer that we’re pointed toward an a evolutionary breakthrough of some sort. What else could “speed up” suggest? The article muddies the waters further with these poorly framed quotes by Steve Jones, a genetics professor at of University College London:
“The general picture that evolution has speeded up in the last 10,000 years as we change from, to put it bluntly, being animals to being humans is clearly true,” he explained. “To suggest it is happening at this instant, I would suggest, is probably wrong.”
“At the moment we are in an evolutionary interval. We are in between two storms. One storm has more or less blown itself out, the storm of farming.”
I won’t bother to comment on the idiotic suggestion that humans aren’t animals. The more immediate problem is timescale. In evolutionary time, 10,000 years is almost nothing. Whether you believe in gradualism or punctuated equilibrium or some blend of both, it typically takes tens of thousands of years to observe changes to the genotype that aren’t merely chromosomal variations. Evolution is happening now, this instant; it’s always happening. But it isn’t instantaneous. Neither is a sunrise. Disclaiming such a thing is absurd to even a novice.
Perhaps it’s worthwhile to remind gentle readers not to get science news from the popular press. Whereas the study may have uncovered something meaningful to a geneticist, it holds almost no value to the general public the way it is reported and veers dangerously toward suggesting things from the realm of science fiction. Science is very good at discovering how things work. It’s not so good at predicting things or even extrapolating trends more than one step beyond the evidence. Take the “suggestion” of human evolution “speeding up” with a sizeable grain of salt.