Growth and Development of Baboons

Messenger RNA levels were measured in actively dividing fibroblasts isolated from young, middle-age, and old-age humans and humans with progeria, a rare genetic disorder characterized by accelerated aging. Genes whose expression is associated with age-related phenotypes and diseases were identified. The data also suggest that an underlying mechanism of the aging process involves increasing errors in the mitotic machinery of dividing cells in the postreproductive stage of life. We propose that this dysfunction leads to chromosomal pathologies that result in misregulation of genes involved in the aging process.

This study investigates brain size ontogeny in a sample of seven anthropoid primate species (including humans) in order to evaluate longstanding ideas about the relations between brain size, brain ontogeny, life history, and cognition. First, this analysis tests the hypothesis that primate brain growth patterns vary across species. Second, the relations between the duration of the brain growth period and the duration of the pre-adult period are evaluated. Brain growth data, derived from a number of sources, are analyzed through parametric and nonparametric regressions. The results indicate that primates are characterized by significant variation in patterns of brain growth. In addition, the degree to which brain growth is allocated to either the pre- or the postnatal period varies substantially. Analyses of phylogenetically adjusted data show no correlation between the lengths of the brain growth period and the juvenile period, but there are correlations with other life-history variables. These results are explained in terms of maternal metabolic adaptations. Specifically, primates appear to present at least two major metabolic adaptations. In the first, brain growth occurs mainly during the prenatal period, reflecting heavy maternal investment. In the second, brain growth occupies large portions of the postnatal period. These differing patterns have important implications for maturation age, necessitating late maternal maturation in the first case and enabling relatively early maternal maturation in the second. Overall, these adaptations represent components of distinctive life-history adaptations, with potentially important implications for the evolution of primate cognition. Copyright 2004 Wiley-Liss, Inc.

We present body mass (N = 419) and crown-rump length (CRL, N = 210) measurements from 38 male and 49 female mandrills born into a semifree-ranging colony in order to describe growth from birth to adulthood, and to investigate maternal influences upon growth. Adult male mandrills are 3.4 times the body mass, and 1.3 times the CRL, of adult females. Body mass dimorphism arises from a combination of sex differences in length of the growth period (females attain adult body mass at 7 years, males at 10 years) and growth rate. Both sexes undergo a subadult growth spurt in body mass, and this is much more dramatic in males (peak velocity 551 g/months +/- 89 SEM at 84-96 months). CRL dimorphism arises from bimaturism (females attain adult CRL at 6 years, males after 10 years), and neither sex shows a particular subadult growth spurt in CRL. Sexual size dimorphism thus represents important time and metabolic costs to males, who mature physically approximately 3-4 years after females. Considerable interindividual variation occurs in the size-for-age of both sexes, which is related to maternal variables. Older mothers have heavier offspring than do younger mothers, and higher-ranking mothers have heavier offspring than do lower ranking mothers. Mass advantages conferred upon offspring during lactation by older and higher-ranking mothers tend to persist postweaning in both sexes. Thus maternal factors affect reproductive success in both sexes, influencing the age at which offspring mature and begin their reproductive career. Copyright 2001 Wiley-Liss, Inc.