To understand the evolutionary forces that have shaped primate lactation strategies, it is important to understand the proximate mechanisms of milk synthesis and their ecological and phylogenetic contexts. The lactation strategy of a species has four interrelated dimensions: the frequency and duration of nursing bouts, the period of lactation until weaning, the number and sex ratio of infants that a mother rears simultaneously, and the composition and yield of the milk that mothers synthesize. Milk synthesis, arguably the most physiologically costly component of rearing infants, remains the least studied. Energy transfer becomes energetically less efficient, transitioning from placental support to milk synthesis just as the energy requirements for infant growth, development, and behavioral activity substantially increase. Here we review primate lactation biology and milk synthesis, integrating studies from anthropology, biology, nutrition, animal science, immunology, and biochemistry, to identify the derived and ancestral features of primate milks and enhance our understanding of primate life history.

The authors surveyed subadult human skeletons from Native American archeological sites in the United States for evidence of skeletal lesions associated with scurvy. Geographic regions surveyed include the Midatlantic area, the Southeast (Florida), the Southwest, and the Plains. The prevalence of probable subadult scurvy ranged from zero in the Plains samples to 38% in a small sample from Florida. These data indicate the likelihood that scurvy was a significant childhood disease in many Native American groups. Reasons for variation in prevalence remain speculative but include regional and seasonal variation in food types and abundance, cultural patterns of storage and utilization, periodic food shortages, and the relative importance of corn in the diet. These factors are part of a nutritional complex that is related to disease prevalence which can be studied through evidence seen in archeological human remains.

Human milk is a complex and variable fluid of increasing interest to human biologists who study nutrition and health. The collection and analysis of human milk poses many practical and ethical challenges to field workers, who must balance both appropriate methodology with the needs of participating mothers and infants and logistical challenges to collection and analysis. In this review, we address various collection methods, volume measurements, and ethical considerations and make recommendations for field researchers. We also review frequently used methods for the analysis of fat, protein, sugars/lactose, and specific biomarkers in human milk. Finally, we address new technologies in human milk research, the MIRIS Human Milk Analyzer and dried milk spots, which will improve the ability of human biologists and anthropologists to study human milk in field settings. Am.