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Comment by stcredzero | Hacker News Reader

> 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.”

We have documented measurable evolution in large mammals in timespans of only several hundred years.

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What's more, we have evidence that the lactose processing gene has become widespread in humans in the last 7000 years.

Not to mention the genetic changes that have occurred in the foods over those times.

Here's my new favourite example for this recent evolution, a paper showing that when we domesticated dogs, their genetic makeup changed to accommodate for a starch-rich diet as shared with humans.

>The genomic signature of dog domestication reveals adaptation to a starch-rich diet [1]

>Nineteen of these regions contain genes important in brain function, eight of which belong to nervous system development pathways and potentially underlie behavioural changes central to dog domestication6. Ten genes with key roles in starch digestion and fat metabolism also show signals of selection.

[1] http://www.nature.com/nature/journal/vaop/ncurrent/full/natu...

Lactase persistence is simply a gene we're born with failing to turn off. Hardly a radical evolutionary change. Animals which eat plant or grain-based diets have completely different digestive systems than humans.

"We have documented measurable evolution in large mammals in timespans of only several hundred years."

So, the good news is that in perhaps merely several hundred years, a diet consisting of lifetime unlimited quantities of regular Mt Dew, tv dinners, bacon, and potato chips will none the less evolve humans who successfully reproduce. Oh wait, whoops, all these people are medically crashing with lifestyle diseases at age 40 after having 10 kids. And meanwhile for those couple hundred years, any small segment of the population who avoids evolving will personally benefit..

There is also a horrific ethical component to evolving mankind for profit. So Monsanto, Dow, etc make a lot of money, at the cost of hundreds of years of humanity dying young in agony. Hmm. It sort of like saying we "should" evolve ourselves to tolerate lead in the environment, or tolerate any other poison. I don't think that quantity of human suffering because of the evolutionary process balances out with some megacorps making a couple extra bucks. I mean, if killing ourselves via diet educated us, or permanently improved the ecology of the planet, or sent us to the stars, or improved our culture, well, not definitely yes, but "maybe". But all that suffering merely for a goal of "some rich dirtbag will get richer", well, uh, "no thanks".

The "plenty of time" of time argument only shows that Cordain's reasoning is not bulletproof -- it doesn't refute it. Just because it's possible to adapt to a new condition doesn't mean we will, or that our adaptation will be complete. Lactase persistence may be evidence of evolution in a relatively short time, but by the same token lactose intolerance is evidence of its failure.

So while it's a fair point of criticism of the paleo argument, it's not enough to dismiss it. If you find a flaw in the proof of a theorem, you have not disproved the theorem.

That's shifting the burden of proof. It's Cordain that is making the claim and promoting a diet, he should provide the evidence, not Zuk.

These are orthogonal issues. Yes, Cordain should provide proof for the diet he champions. Separately from that, she has written a book called "Paleofantasy" which implies proof that the diet's precepts are invalid. Hence from her side showing that they might be invalid is not enough.

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