FIGURE 6-1 Duration of several life history stages as a function of body size in anthropoid primates.

SOURCE: Data primarily from compilations in Smuts et al. (1987), updated in Lee (1999) and references therein.

genera are analyzed. Consequently, single species such as humans or baboons represent at most a single point in the analyses. From that coarse perspective, several generalities can be made about the life history traits of various mammals. First, these traits covary and cluster along a continuum, such that some species have “fast” life histories—rapid offspring growth rates, early maturation, high rates of reproduction, and short reproductive spans (high adult mortality). At the other extreme are species with “slow” life histories—low rates of offspring growth, late maturation, low rates of reproduction and adult mortality. Second, large-bodied mammals tend to have slow life histories, small-bodied ones fast life histories (see Figure 6-1 for anthropoid primates). Third, although this pattern of a fast-slow continuum can be seen in all orders of mammals, the tendency toward slow or fast life histories also differs greatly among the various orders of mammals—carnivores versus primates, for example. Mammals of the same size in different orders differ fairly consistently in slow or fast life history style, and primates, mainly anthropoid primates, have particularly slow life histories. Finally, another interesting feature of the fast-slow continuum is that many life history traits, such as growth rates and adult mortality rates