Humans were eating refined starches 20k years before agriculture
jetlib.com
jetlib.com
In any case, after reading the article, I am not sure about the conclusions done by most of the newspapers that I have read.
1. Most of the flour that they are talking about is referred to roots, which in most cases are encouraged in the paleo diet. 2. I miss a more detailed study about the grains that they found: amount of phytates, lectins, gluten... 3. I am also curious about the methods that they used to cook/processing the grains to avoid poisoning. In the study they talk about the process prior to eating as: "The flour would have undergone a multistep processing involving root peeling, drying, and finally grinding using specific tools".
Also it would need some evidence of granaries or the like for winter storage.
If Stone Age humans did have refined starches in their diet, then if you wanted to follow a truly paleolithic diet you would eat flour.
Of course, I never bought the diet to begin with for totally different reasons, which is that 10,000 years is plenty of time to adapt to a new diet. I prefer the pre-industrial diet. It's obvious that fast food is bad for us, it's not obvious that pasta is generally evil.