No, there is not strong evidence that humans mental evolution is related to animal products. The very theory that it is based on has been completely debunked (
http://paleovegan.blogspot.com.au/2011/11/its-curtains-for-expensive-tissue.html). Doesn't stop the meat industry saying it, but it should.
The American Dietetic Society is clear that a plant based diet is suitable for humans through every phase of their life, including pregnancy, lactation, infancy, childhood, and adolescence, and for
athletes. If you have additional information that they are not familiar with, can you provide links please?