Magpie, thank you. Perhaps when I am ninety, I will have mastered as much of the web as my granddaughter, Athena, knew when she was two. I guess that explains why the moderator who introduced Sam spoke first in Spanish. I thought it was just a Santa Fe thing.
Jerry Fresia raises a very interesting question with his comment about the distinction between wealth and capital. Wealth is stuff -- land, or at least control over it, dibs on water holes [very important in the society of the !Kung of the Sahara], food, clothing, shelter, tools, weapons, art works, machinery, raw materials, mines and the ore in them, and so forth. Capital is wealth that can be invested to employ labor , produce commodities, and make a profit. In order for something to be capital, a complex structure of social relations of production and distribution must be in place. Hence, the exclusive access to females of child-bearing age in a community of primates [one of Sam's examples of unequal distribution of wealth early on] may by some extended sense of the term be denominated wealth, but it cannot be called capital. Nor can control over land, or piles of weapons, or even the right to demand the labor services of peasants farming the land one controls. Indeed, piles of gold coins do not constitute capital in a society that does not have the social structure required for commodity production.
Piketty seems to understand the distinction, but he says at various points in his book that he is not going to try to draw that distinction because he is completely dependent on data sets, such as tax records and inheritance records, in which the distinction is not made. It seems to me that you can fault him for having undertaken the research program at all if he could not guarantee to maintain the distinction in his results, but I am not powerfully persuaded by that argument. I guess I think like an historian who is forced to work with whatever posterity has left for us, even though it may not be what we would have preferred in the way of data. [I stumbled on an op ed essay by Joseph Stiglitz, whom I very much admire -- I have lost the link, alas -- in which he argues that a good deal of the dramatic increase in wealth by the richest members of our society is a form of appropriation of rents rather than an accumulation of investible capital that could be employed to expand the economy.]
Now, since Sam wants to talk about patterns of inequality going back two million years [!!!], he cannot be talking about capital, because by no stretch of the imagination can the unequal accumulations of wealth in pastoral or hunter-gatherer or feudal societies be called capital accumulation.
It may be, of course, that I am just getting into the mood for my UNC course, which starts in only twelve days [yikes], but it does seem to me that Marx had a better grasp on these matters than many who have succeeded him, for all that his analytic methods were primitive and his data now quite dated.