Modern day produce is often artificially modified to have desirable characteristics. For example, before modification, corn was a straggly grass, bananas were full of seeds and tomatoes were in fact small berries. However the paleo diet insists that we as humans are biologically identical to our ancestors, therefore denying any process of evolution.
An example of evolution in humans which proves we are not identical to our ancestors is lactase persistence. After infancy, the gene that breaks down lactose (called lactase) no longer functions and therefore creates lactose intolerance as there is no mechanism to break down the lactose disaccharide. Humans have evolved to continually produce the lactase gene and therefore are still able to consume products containing lactose including dairy products.
These processes of human evolution and artificial modification of plants therefore raises question to whether the paleo diet is really replicating the diet of our Palaeolithic ancestors. In addition there were clearly no paleo protein bars nor flourless cakes available during the Palaeolithic period.
Therefore, while the paleo diet may be effective in certain circumstances, it doesn’t accurately reflect the diet habits of humans during the Palaeolithic period.