Aside from the fact that most Vegans are Vegan for humanitarian issues, both of these diets have similar supporting arguments that they are better for your nutrition.
What the heck is Pegan? I hear you ask... Pegan is the combination of the Paleo and Vegan diets to create, in a way, one SUPER-diet. (Kind of like Super-foods) having recently started eating Paleo I was quite interested in this article.
The main gist of the article is that Paleo and Vegan diets both offer great health and nutritional advantages which can be very similar. A Vegan diet eliminates ALL animal products (Meat, Fish, Poultry, Dairy & Eggs) and only consumes fruit, vegetables, nuts & seeds, and grains as their main diet. A Paleo diet eliminates dairy, eggs, grains and legumes, yet allows you to consume meat, fruit, vegetables, nuts (except peanuts) & seeds. Both diets also focus on only using whole food products such as organic, non GMO, sugar-free (or no added sugar as fruit contains a natural sugar known as fructose), consumption of good quality fats (Olive oil, avocado, nuts and seeds), and chemical free (no additives or preservatives).
The main argument that both Vegan and Paleo share is that Dairy products are shown to be inflammatory which can contribute to obesity, diabetes, heart disease and cancer.
Dr Mark's main idea about "Pegan" is amalgamating the two diets together by combining each of the main ideas and arguments into one, as I said before, super-diet. The great thing about this is that if I were to take on the Pegan I could essentially add back my grains and pastas which I love dearly as well as adhering to the Paleo principles of eating meat etc...
Dr Mark gave the best explanation of of going Paleo... "Eat meat as a condiment instead of the main course"
To read Dr Mark's full article on Pegan and how to become Pegan, follow the link here.