Barter, Tools, Evolution

According to Smith, what distinguishes humans from other species is the propensity to "truck, barter, and exchange".  According to Marx, the "first premise of human existence" and "of all history" is the "production of the means to satisfy" fundamental needs.  In other words, according to the former, barter, etc. is the defining Human characteristic, while according to the latter, it is tool-making.  Now, according to Darwin, the distinctive Human characteristics are several physiological features, including thumbs of unprecedented versatility.  Plainly, the latter is the pre-condition of the making of and use of tools.  Furthermore, the objects of barter, etc. are all products of some manufacturing process.  Thus, Evolutionism is much closer to Marxism than to Capitalism in two respects--what the defining characteristic of Human is, and that the appearance of that characteristic marks the beginning of Human history.