Matt Yglesais declares the Paleo Diet to be Nonsense Science, so we are confident that there is some nonsense around.
He takes his cue from Laura Miller of Salon, who in turn is citing "Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live" by Marlene Zuk.
Let me set the stage with Ms. Miller's intro:
Four years ago, biology professor Marlene Zuk was attending a conference on evolution and diseases of modern environments. She sat in on a presentation by Loren Cordain, author of “The Paleo Diet” and a leading guru of the current craze for emulating the lifestyles of our Stone-Age ancestors. Cordain pronounced several foods (bread, rice, potatoes) to be the cause of a fatal condition in people carrying certain genes. Intrigued, Zuk stood up and asked Cordain why this genetic inability to digest so many common foods had persisted. “Surely it would have been selected out of the population,” she suggested.
Cordain, who has a Ph.D in exercise physiology, assured Zuk that human beings had not had time to adapt to foods that only became staples with the advent of agriculture. “It’s only been ten thousand years,” he explained. Zuk’s response: “Plenty of time.” He looked at her blankly, and she repeated: “Plenty of time.” Zuk goes on to write, “we never resolved our disagreement.”
Plenty of time? Matt goes on to provide examples of rapid evolution, which certainly makes a convincing case that evolution can occur rapidly. Of course, that is a far cry from answering the question at hand - has evolution kept pace with human's ability to digest certain modern foods?
I don't know the specific syndrome that led to the dispute between Cordain and Zuk, but let's imagine that it is celiac. Per the NY Times science section, the predisposition to celiac is hereditary, and it surely can be fatal if untreated. That leads me to conclude that, Ms. Zuk's assertion of "plenty of time" notwithstanding, humanity has not yet bred away all of its problems with wheat gluten.
Also on offer is the example of man's adaptation to cow's milk; left unmentioned is that roughly 7,000 years after domesticating cows and goats the majority of people worldwide cannot digest this otherwise excellent food source. That is an example of evolution creeping, not sprinting.
As to how neither Mr. Yglesias nor Ms. Miller happened to think of that fairly obvious example of an evolutionary 'fail' linked to our modern diet, well, I have a theory. Folks of a conservative temperment believe that the accumulated customs and institutions of the past reflect the conclusions of people who may have had excellent, if not immediately discernible, reasons for what they did. Progressives would much rather convene a panel of experts and reinvent a solution to whatever problem is at hand.
On the dietary front, this inclination leads to Mr. Yglesais rubbishing two million years of human eating practices because a scientist told him to ignore it. Of course, years back it led George McGovern to weigh in on the side of Ancel Keys and the other experts who had decided that dietary fat was the crisis facing America. Oops.
MORE: From the Times on gluten sensitivty and gluten intolerance:
As with most nutrition controversies, most everyone agrees on the underlying facts. Wheat entered the human diet only about 10,000 years ago, with the advent of agriculture.
“For the previous 250,000 years, man had evolved without having this very strange protein in his gut,” Dr. Guandalini said. “And as a result, this is a really strange, different protein which the human intestine cannot fully digest. Many people did not adapt to these great environmental changes, so some adverse effects related to gluten ingestion developed around that time.”
The primary proteins in wheat gluten are glutenin and gliadin, and gliadin contains repeating patterns of amino acids that the human digestive system cannot break down.
So 10,000 years later, no one can actually digest gluten. Many of us, however, can pass it through with no apparent ill effects.
This health criteria - it doesn't help, but maybe it doesn't hurt - would not pass muster with the left if the topic were any food additive or GMO.