The paleo diet is based on the idea that humans have not evolved quickly enough to eat a modern diet, and that therefore we should eat like neolithic hunter-gatherers of 50,000 years ago as that is what our bodies have evolved to consume.
Entirely incorrect. Genetic studies have proven that genes involved with diet have been highly selected for over only the last few thousand years - lactose tolerance has evolved three separate times by three different genetic pathways within the last 6,000 years, for instance.
Studies of the human microbiome now underway are demonstrating how little of the human genome, and how much of our commensal passengers (who evolve much faster than us) are involved in digestion.
In short the scientific hypothesis behind the paleo diet has been completely falsified. Hence my comparison to homeopathy.