Todd Moody wrote:
> Why famine only?  Tubers are a high energy density food.

Also high carbohydrate.
>  They are not unduly difficult to gather. The Expensive Tissue hypothesis, which I accept, stipulates that the evolutionary decrease in the gut-brain ratio depends on a higher density diet. 

High carbohydrate consumption = big belly.

> I believe meat must have dominated but I don't see any reason to suppose it did so to the exclusion of other high density foods, such as tubers.

Carnivores should be more likely to survive.

>  Moreover, the fact that cooking shows up about 25-50,000 years before homo sapiens, but a long time before the Neolithic, is at least suggestive. 
Fire /= cooking.
It was and is a tool, including social.


> I understand that paleolithic tubers would have been pretty gnarly in comparison with modern selectively bred mega-starches but I just don't see any reason to think that paleo people ignored them. 
>   


They might have used them for bait for animals unlucky enough (small 
brains)  to not know the difference between food and fodder.
>   
William