John C. Hudson

Age and sex differences in body size and composition during Rhesus monkey adulthood

Body size and composition were measured in forty-one adult Rhesus monkeys (Macaca mulatta) in order to characterize changes that occur during later life for both genders. Data were obtained by traditional somatometric techniques and by dual-energy X-ray absorptiometry. Representative monkeys were chosen within six categories defined by age (Young Adult, 6–9 yearold; Middle Aged, 15–19 year-old; Older Adult, 26–30 year-old), and sex. Body weight and most external measures of body size were greater during middle age and later life than in young adulthood, as were body fat content and lean body mass. Females tended to have a higher percentage body fat than males in all age categories. Lean tissue mass was markedly greater in the two younger groups for both sexes, compared to older adults. Bone mineral content and density were higher in the males than the females, but differences in bone mineralization among age groups did not achieve statistical significance. Such data derived from adult nonhuman primates are useful for defining fundamental biological changes with age in these species, and have value as a comparative model for studies of human aging and age-related morbidity.

Environment, Culture, and the Great Lakes Fisheries

The commercial fisheries of the United States and Canadian Great Lakes are in a long period of decline. Detailed statistics kept for well over a century document a fluctuating pattern of harvests of the major commercial species. In the 1940s, sea lamprey began to devastate the fisheries, an effect that has not been fully countered. Overfishing, nonnative species, declining nutrient levels, and chemical pollution have contributed to reduced catches. Court decisions in the United States and Canada during the past thirty years have awarded a sizable share of commercial fishing rights to Native North Americans for their own support and sustenance. The Lake Erie yellow perch and walleye fishery, based mainly in Ontario, is the most successful commercial fishing operation in the region. Despite the many environmental and cultural challenges, the Great Lakes fisheries live on.

Elementary models for population growth and distribution analysis

A version of the Lotka-Volterra interaction model is adapted to describe population growth and migration processes in a two-region system. The regions are identified as a metropolis and its non-metropolitan hinterland. Several conditions on growth and migration regimes are imposed. The time behavior of the systems are analyzed, noting especially situations where total depopulation or population explosion eventually occur in one or both populations. Neither growth control nor migration control alone results in a condition of long-run stability in both regions. If at least a momentary condition of zero growth is achieved in both regions, it is possible to maintain finite populations if each population follows a logistic natural growth process and migration flow is proportional to the volume of interaction. It is necessary also that the natural increase limitation is strong relative to migration rates. This result holds even if one population has a net migration advantage over the other.

Cultural Geography and the Upper Great Lakes Region

The Upper Great Lakes region often is interpreted as a cultural mosaic of ethnic groups identified with marginal farming, forestry and mining settlements. Despite its early history of a large, foreign-horn population, many of the regions pioneer settlers can be identified with an international source region, neither truly American nor truly Canadian, the upper St. Lawrence Valley. Forest-fringe agriculture, seasonal work for cash wages and employment in large-scale resource extraction were part of the way of life brought from the St. Lawrence district to the northern portions of Michigan, Wisconsin and Minnesota. The southern limit of the so-called “Cutover” region coincides with a transition toward a preponderance of settlers from western New York, who brought traditions of wheat and dairy farming, compact settlements and democratic institutions to the upper Middle West.

Chicago: Patterns of the Metropolis

Abstract Thematic maps reveal the geography of any area. A series of such maps introduces the growth, landforms, railroad lines, African-American population, population density, and population change in Chicago. Many of these patterns have been laid down in past times, but they also influence present and future trends.