The Russian Anarchist Kropotkin, in his classic Mutual Aid, explores an oft forgotten part of our evolutionary history. In opposition to the "war of all against all" envisioned by Thomas Hobbes, the theory that led to Malthusian Darwinism, Kropotkin explains that mutual aid is an important factor in our evolution. According to Kropotkin species become weak and doomed to extinctions without mutual aid. He shows examples of mutual aid from both non-human animals and historic human societies from the beginning of human history up to the time of Kropotkin himself.
Mutual Aid: A Factor of Evolution is a core work in Anarchist theory. I have been able to make this important text available thanks to libcom.org: