They are correct that punctuated equilibria apply to sexually reproducing organisms and that morphological evolutionary change is regarded as largely (if not exclusively) correlated with speciation events. However, they err in suggesting that we attribute stasis strictly to "developmental constraints," which represent only one of a set of possible mechanisms that we have suggested for the causes of stasis. Others include habitat tracking and the internal structure of species themselves [for example, (2)].

The dramatic rise in inequality in the United States over the past generation has occasioned considerable attention from economists, but strikingly little from students of American politics. This has started to change: in recent years, a small but growing body of political science research on rising inequality has challenged standard economic accounts that emphasize apolitical processes of economic change. For all the sophistication of this new scholarship, however, it too fails to provide a compelling account of the political sources and (...) effects of rising inequality. In particular, these studies share with dominant economic accounts three weaknesses: they downplay the distinctive feature of American inequality —namely, the extreme concentration of income gains at the top of the economic ladder; they miss the profound role of government policy in creating this “winner-take-all” pattern; and they give little attention or weight to the dramatic long-term transformation of the organizational landscape of American politics that lies behind these changes in policy. These weaknesses are interrelated, stemming ultimately from a conception of politics that emphasizes the sway of the “median voter” in electoral politics, rather than the influence of organized interests in the process of policy making. A perspective centered on organizational and policy change —one that identifies the major policy shifts that have bolstered the economic standing of those at the top and then links those shifts to concrete organizational efforts by resourceful private interests —fares much better at explaining why the American political economy has become distinctively winner-take-all. (shrink)