Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
198
result(s) for
"Donald Grayson"
Sort by:
The great basin : a natural prehistory
\"The Great Basin, centering on Nevada and including substantial parts of California, Oregon, and Utah, gets its name from the fact that none of its rivers or streams flow to the sea. This book synthesizes the past 25,000 years of the natural history of this vast region. It explores the extinct animals that lived in the Great Basin during the Ice Age and recounts the rise and fall of the massive Ice Age lakes that existed here. It explains why trees once grew 13' beneath what is now the surface of Lake Tahoe, explores the nearly two dozen Great Basin mountain ranges that once held substantial glaciers, and tells the remarkable story of how pinyon pine came to cover some 17,000,000 acres of the Great Basin in the relatively recent past.These discussions culminate with the impressive history of the prehistoric people of the Great Basin, a history that shows how human societies dealt with nearly 13,000 years of climate change on this often-challenging landscape\"--Provided by publisher.
Book
The Great Basin
Covering a large swath of the American West, the Great Basin, centered in Nevada and including parts of California, Utah, and Oregon, is named for the unusual fact that none of its rivers or streams flow into the sea. This fascinating illustrated journey through deep time is the definitive environmental and human history of this beautiful and little traveled region, home to Death Valley, the Great Salt Lake, Lake Tahoe, and the Bonneville Salt Flats. Donald K. Grayson synthesizes what we now know about the past 25,000 years in the Great Basin—its climate, lakes, glaciers, plants, animals, and peoples—based on information gleaned from the region’s exquisite natural archives in such repositories as lake cores, packrat middens, tree rings, and archaeological sites. A perfect guide for students, scholars, travelers, and general readers alike, the book weaves together history, archaeology, botany, geology, biogeography, and other disciplines into one compelling panorama across a truly unique American landscape.
eBook
Early human dispersals within the Americas
The expansion into the Americas by the ancestors of present day Native Americans has been difficult to tease apart from analyses of present day populations. To understand how humans diverged and spread across North and South America, Moreno-Mayar
et al.
sequenced 15 ancient human genomes from Alaska to Patagonia. Analysis of the oldest genomes suggests that there was an early split within Beringian populations, giving rise to the Northern and Southern lineages. Because population history cannot be explained by simple models or patterns of dispersal, it seems that people moved out of Beringia and across the continents in a complex manner.
Science
, this issue p.
eaav2621
Ancient genomes from the Americas show a complex genetic history giving rise to present-day diversity.
Studies of the peopling of the Americas have focused on the timing and number of initial migrations. Less attention has been paid to the subsequent spread of people within the Americas. We sequenced 15 ancient human genomes spanning from Alaska to Patagonia; six are ≥10,000 years old (up to ~18× coverage). All are most closely related to Native Americans, including those from an Ancient Beringian individual and two morphologically distinct “Paleoamericans.” We found evidence of rapid dispersal and early diversification that included previously unknown groups as people moved south. This resulted in multiple independent, geographically uneven migrations, including one that provides clues of a Late Pleistocene Australasian genetic signal, as well as a later Mesoamerican-related expansion. These led to complex and dynamic population histories from North to South America.
Journal Article
Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea)
Around 88 large vertebrate taxa disappeared from Sahul sometime during the Pleistocene, with the majority of losses (54 taxa) clearly taking place within the last 400,000 years. The largest was the 2.8-ton browsing Diprotodon optatum, whereas the ~100- to 130-kg marsupial lion, Thylacoleo carnifex, the world's most specialized mammalian carnivore, and Varanus priscus, the largest lizard known, were formidable predators. Explanations for these extinctions have centered on climatic change or human activities. Here, we review the evidence and arguments for both. Human involvement in the disappearance of some species remains possible but unproven. Mounting evidence points to the loss of most species before the peopling of Sahul (circa 50-45 ka) and a significant role for climate change in the disappearance of the continent's megafauna.
Journal Article
A brief history of Great Basin pikas
Aim Within the past few decades, seven of the 25 historically described populations of American pikas (Ochotona princeps) in the Great Basin of arid western North America appear to have become extinct. In this paper, the prehistoric record for pikas in the Great Basin is used to place these losses in deeper historical context. Location The Great Basin, or area of internal drainage, of the western United States. Methods The location, elevation, and age of all reported prehistoric Great Basin specimens of American pikas were extracted from the literature. Elevations of extinct pika populations were arrayed through time, and latitudes and longitudes of those populations used to determine changing distances of those populations from the nearest extant populations. Results The average elevation of now-extinct Great Basin pika populations during the late Wisconsinan (c. 40,000-10,000 radiocarbon years ago) and early Holocene (c. 10,000-7500 years ago) was 1750 m. During the hot and dry middle Holocene (c. 7500-4500 years ago), the average elevation of these populations rose 435 m, to 2168 m. All prehistorically known late Holocene (c. 4500-200 years ago) populations in the Great Basin are from mountain ranges that currently support populations of this animal, but historic period losses have caused the average elevation of pika populations to rise an additional 152 m. The total elevational increase, from the late Wisconsinan and early Holocene to today, has been 783 m. As lower elevation pika populations were lost, their distribution increasingly came to resemble its modern form. During the late Wisconsinan, now-extinct pika populations were located an average of 170 km from the nearest extant population. By the late Holocene, this distance had declined to 30 km. Main conclusions Prehistoric alterations in the distribution of pika population in the Great Basin were driven by climate change and attendant impacts on vegetation. Today, Great Basin pikas contend with both climate change and anthropogenic impacts and thus may be on the brink of extinction.
Journal Article
Hawai‘i’s Toxic Plants: Species Richness and Species–Area Relationships
The Hawaiian Islands have long been seen as relatively devoid of native toxic plant species, a result of the paucity of herbivorous predators in this biogeographically isolated archipelago. This assertion has been subjective, without quantitative comparison to floras that evolved in the presence of such predators. We test this assertion by comparing the richness of toxic species in the native flora of the main Hawaiian Islands to that in the naturalized flora of these islands. That test shows the assertion to be correct: the relative abundance of toxic plant species in the naturalized Hawaiian flora is nearly ten times greater than the relative abundance of those species in the Hawaiian native flora. Of the approximately 150 toxic plant species now found in these islands, 92% are naturalized. The species richness of both native and naturalized Hawaiian plant species correlates positively with island size, as does the richness of toxic native and toxic naturalized plant species. These results, and the lack of significant residuals in species–area relationships across the main Hawaiian Islands, suggest that the relative youth of Hawai‘i Island is not needed to account for native plant species richness on this island.
Journal Article
Hawai'i's Toxic Plants: Species Richness and Species-Area Relationships
The Hawaiian Islands have long been seen as relatively devoid of native toxic plant species, a result of the paucity of herbivorous predators in this biogeographically isolated archipelago. This assertion has been subjective, without quantitative comparison to floras that evolved in the presence of such predators. We test this assertion by comparing the richness of toxic species in the native flora of the main Hawaiian Islands to that in the naturalized flora of these islands. That test shows the assertion to be correct: the relative abundance of toxic plant species in the naturalized Hawaiian flora is nearly ten times greater than the relative abundance of those species in the Hawaiian native flora. Of the approximately 150 toxic plant species now found in these islands, 92% are naturalized. The species richness of both native and naturalized Hawaiian plant species correlates positively with island size, as does the richness of toxic native and toxic naturalized plant species. These results, and the lack of significant residuals in species-area relationships across the main Hawaiian Islands, suggest that the relative youth of Hawai'i Island is not needed to account for native plant species richness on this island. Keywords: Hawaiian Islands, island biogeography, toxic plants, species-area relationships, extinct birds, moa-nalos
Journal Article
Deciphering North American Pleistocene Extinctions
The debate over the cause of North American Pleistocene extinctions may be further from resolution than it has ever been in its 200-year history and is certainly more heated than it has ever been before. Here, I suggest that the reason for this may lie in the fact that paleontologists have not heeded one of the key biogeographic concepts that they themselves helped to establish: that histories of assemblages of species can be understood only be deciphering the history of each individual species within that assemblage. This failure seems to result from assumptions first made about the nature of the North American extinctions during the 1960s.
Journal Article
Middle-Holocene climates and human population densities in the Great Basin, western USA
Much of western North America saw higher temperatures and lower precipitation during the middle Holocene. The Great Basin became much drier and warmer than it is today, causing major shifts in lake levels, treelines, plant community composition, and vertebrate distributions and abundances. To assess the impact of climate change on middle-Holocene human population densities in this region, we examine the frequency structures of radiocarbon-dated archaeological sites through time in three separate parts of the Great Basin: the Bonneville Basin, Fort Rock Basin, and western Lahontan Basin. The results of the analysis support the hypothesis that human population densities in many parts of the Great Basin dropped substantially in response to middle-Holocene climate change but also document that there were intervals during the middle Holocene in all three areas that appear to have been marked by temporary population increases. We hypothesize that these increases were associated with equally temporary increases in effective precipitation but, lacking adequate paleoenvironmental data, do not attempt to test this hypothesis.
Journal Article