The evolution of Pleistocene mammals is characterized by giantism and in the ungulates by the appearance of huge and often bizarre horns, antlers, ossicones, and tusks. An earlier study of sheep (Ovis) led to a theory explaining these phenomena. This theory, termed the “dispersal theory,” is described briefly and then applied to the evolution of Old World deer (Cervinea, Baird, 1857). It is shown that the zoogeography and physical characteristics of Old World deer follow the predictions of this theory. Attention is drawn to the parallels in zoogeography and convergent evolutionary changes between Old World deer and other ungulates such as New World deer, the goats and sheep and the genus Bison. The application of the “dispersal theory” to the evolution of the genus Bison shows that it is compatible with known facts and that it explains aspects of Bison morphology not usually considered. It also suggested a new and testable hypothesis of the origin of present-day Bison. In general the “dispersal theory” applied to Pleistocene conditions predicts that a specialization of social behavior and social organs leading to giantism, altered body proportions and bizarre hornlike organs occurs during postglacial dispersal into new habitat. It also describes the characteristics of these early, pioneering populations. In so doing it links the disciplines of animal behavior, ecology, animal science, population dynamics, and zoogeography into a functional whole. In particular it shows the relationship between ecology and social behavior. Finally, the “dispersal theory” is shown to be a general theory, applicable to Pleistocene and pre-Pleistocene conditions. In the tropics or pre-Pleistocene conditions social evolution follows ecological specialization, while in the periglacial zones social evolution only reflects the colonization history of the species. It is shown that the “dispersal theory” unites the apparently contradictory views on evolution and zoogeography of Matthews and Darlington. Matthews' views apply largely to Pleistocene conditions and Darlington's to pre-Pleistocene conditions. A preliminary application of the “dispersal theory” to pre-Pleistocene mammals suggests that it predicts correctly.

The intricate pattern of moraines of the Laurentide ice sheet in the Great Lakes region reflects the marked lobation of the ice margin in late Wisconsin time, and this in turn reflects the distribution of steam-cut lowlands etched in preglacial times in the weak-rock belts of gentle Paleozoic fold structures. It is difficult to trace and correlate moraines from lobe to lobe and to evaluate the magnitude of recession before readvance, but three breaks stand out in the sequence, with readvances at about 14,500, 13,000, and 11,500 years ago. The first, corresponding to the Cary advance of the Lake Michigan lobe, is represented to the west by distant advance of the Des Moines lobe in Iowa, and to the east by the overriding of lake beds by the Erie lobe. The 13,000-year advance is best represented by the Port Huron moraine of the Lake Michigan and Huron lobes, but by relatively little action to west and east. The 11,500-year advance is based on the Valders till of the Lake Michigan lobe, but presumed correlations to east and west prove to be generally older, and the question is raised that these and some other ice advances in the Great Lakes region may represent surges of the ice rather than regional climatic change. Surging may involve the buildup of subglacial meltwater, which can provide the basal sliding necessary for rapid forward movement. It would be most favored by the conditions in the western Lake Superior basin, where the Superior lobe had a suitable form and thermal regime, as estimated from geomorphic and paleoclimatic criteria. The Valders advance of the Lake Michigan and Green Bay lobes may also have resulted from a surge: the eastern part of the Lake Superior basin, whence the ice advanced, has a pattern of deep gorges that resemble subglacial tunnel valleys, which imply great quantities of subglacial water that may have produced glacial surges before the water became channeled.

Earlier studies in Alaska and northwest Canada have shown inconsistent evidence for the expected northward extension of the Arctic tree line during the Hypsithermal Interval. Only megafossil evidence has supported this suggestion; the palynological findings have been inconclusive. The Tuktoyaktuk Peninsula, in the Northwest Territories of Canada, offers critical sites for studies of late-Pleistocene ecology, because of its geological, biotic, and climatological features. Palynological and megafossil evidence is presented from sites on the Tuktoyaktuk Peninsula, indicating northward advance of the Arctic tree line during the period 8500-5500 B.P. Relative pollen frequencies of a core of lake sediment suggest a late-Pleistocene sequence as follows: 12,900-11,600 dwarf birch tundra; 11600-8500 forest tundra; 8500-5500 closed-crown spruce-birch forest; 5500-4000 tall shrub tundra; 4000-present dwarf birch heath tundra. These results suggest that during the Hypsithermal Interval the Arctic Front (July position) was further north, over the Beaufort Sea, a displacement from its present position of about 350 km. The Tuktoyaktuk Peninsula, presently occupied by tundra, and dominated by the Arctic airstream in July, was apparently under forest, with warm, moist Pacific air during the Hypsithermal Interval.

Opal phytoliths, inorganic biogenetic plant particles of microscopic size, were investigated to determine the level at which their varied morphology is taxonomically significant. Extraction methods for the isolation of these particles from living plants and from soils were developed to provide maximum preservation of morphological features while remaining simple, rapid, and inexpensive. Extracts were made and microscopically viewed from 30 live specimens, of which 16 were systematically typed in order to develop taxonomic guidelines for their identification in soils. Clear taxonomic differentiation was noted between and within major plant groups with considerable indication that more detailed investigation will yield finer subdivisions. Since opal phytoliths are reported to be a particularly durable fossil found in deposits as far back as Tertiary Age, it appears that opal phytolith analysis can provide paleobotanical information comparable to palynological data in many areas where pollen is absent. When used in conjunction with pollen where present, they should serve to confirm pollen data as well as provide additional botanical data not available in pollen studies.

A preliminary study was made of the magnetic stratigraphy of the Pliocene and Lower Pleistocene marine sediments in Le Castella area, Calabria, Southern Italy. Microbiostratigraphic evidence of the measured sediments provides a basis for tentative correlation with the standard magnetic chronology. The Gilsa Event in the Matuyama Reversed Polarity Epoch is estimated to be a little older than the lower limit of the Calabrian in Le Castella area.

Between the two wars, studies on the Quaternary were scarcely in favor in France. However. from the beginning of the 19th century recent terrains had held the attention of our country’s eminent geologists, and later that of the prehistorians, and starting in the 1850s these terrains were given the first chronological classifications based, on the one hand, on the evolution of Mammals. and on the other hand, on the succession of prehistoric civilizations.

Electrical resistivity field measurements and subsequent laboratory analyses of the electrical properties of soils and rocks, both frozen and unfrozen, are used to describe the type and configuration of permafrost in Wright and Taylor Valleys, Antarctica. Rock and soil samples saturated with potable water have resistivities that increase four orders of magnitude when cooled from +21°C to −25°C. Resistivities greater than 10,000 ohm-m are associated with an impermeable variety of permafrost referred to in this paper as confining permafrost. Confining permafrost is continuous throughout the ice-free valleys except near McMurdo Sound and under saline lakes. A hydrologic connection between lakes and the groundwater reservoir beneath the lakes is inferred; thus, part of the brines contained in the lakes may be derived from groundwater.

Radiocarbon dates of organic matter collected from ablation till or from the base of peat bogs in dead-ice deposits may postdate retreat of an active glacier terminus by hundreds or even thousands of years, and therefore provide only minimum estimates for the time of glacial maximum and the beginning of ice recession. Logs incorporated in Vashon till close to the drift border postdate recession of the Puget Lobe of the Cordilleran Ice Sheet by some 1400 years, and probably were buried when drift-mantled stagnant ice melted away, causing collapse of a superglacial forest.