Spatial Variability of Late-Quaternary Paleoclimates in the Western United States

AbstractA mandible identified as noble marten (Martes americana nobilis) recovered from sediments dating to 11,800 cal yr BP and a humerus identified as M. a. cf. nobilis recovered from sediments dating from 13,100 to 12,500 cal yr BP at the Marmes Rockshelter archaeological site in southeastern Washington represent the first record of this taxon in the state. Mammalian taxa associated with the Marmes Rockshelter noble marten represent a diversity of open mesic habitats corroborating earlier analyses of other records of the noble marten in the western United States and exemplify how paleozoologists determine the ecology and environmental predilections of extinct taxa. The recovery site represents the topographically lowest record of this species in western North America and the farthest north record in the United States. Future research should examine known late-Quaternary Martes spp. remains from British Columbia and Alberta to fill in the 2200-km geographic gap in the known distribution of this taxon between a record in the northern Yukon and those in the western United States, and to refine our knowledge of noble marten paleoecology.

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Phylogeography and population genetics of a widespread cold-adapted ant, Prenolepis imparis

10.22541/au.163820316.61117098/v1 ◽

2021 ◽

Author(s):

Maria Tonione ◽

Ke Bi ◽

Rob Dunn ◽

Andrea Lucky ◽

Neil Tsutsui

Keyword(s):

United States ◽

Gene Flow ◽

Population Genetic ◽

Late Quaternary ◽

Western United States ◽

Glacial Cycles ◽

Cold Adapted ◽

Contemporary Gene Flow ◽

Demographic Patterns

Historical climate fluctuations have left genetic signatures on species and populations across North America. Here, we used phylogenetic and population genetic analyses from 1,402 orthologous sequences of 75 individuals obtained through sequencing of Ultraconserved Elements (UCEs) to identify population genetic structure and historical demographic patterns across the range of a widespread, cold-adapted ant, the winter ant, Prenolepis imparis. We relate the genomic patterns to those expected as a result of in situ diversification, maintained connectivity, or recent migration. We recovered five well-supported, genetically isolated clades across the distribution: 1) a basal lineage located in Florida, 2) populations across the southern United States, 3) populations that span the midwestern and northeastern United States, 4) populations from the western United States, and 5) populations in southwestern Arizona and Mexico. Using Bayesian clustering analysis in STRUCTURE and k-means clustering in ADEGENET, we investigated gene flow between these major genetic clades and did not find evidence of gene flow between clades. We did find evidence of localized structure with migration in the western United States clade. High support for five major geographic lineages and lack of evidence of contemporary gene flow indicate in situ diversification across the species’ range, probably influenced by glacial cycles of the late Quaternary.

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Writing Time in Metaphors

10.3366/edinburgh/9781474423939.003.0004 ◽

2018 ◽

Author(s):

Jennifer J. Smith

Keyword(s):

United States ◽

The United States ◽

Western United States ◽

Entire System ◽

Language And Culture ◽

Space Race ◽

Do So

Coherence of place often exists alongside irregularities in time in cycles, and chapter three turns to cycles linked by temporal markers. Ray Bradbury’s The Martian Chronicles (1950) follows a linear chronology and describes the exploration, conquest, and repopulation of Mars by humans. Conversely, Louise Erdrich’s Love Medicine (1984) jumps back and forth across time to narrate the lives of interconnected families in the western United States. Bradbury’s cycle invokes a confluence of historical forces—time as value-laden, work as a calling, and travel as necessitating standardized time—and contextualizes them in relation to anxieties about the space race. Erdrich’s cycle invokes broader, oppositional conceptions of time—as recursive and arbitrary and as causal and meaningful—to depict time as implicated in an entire system of measurement that made possible the destruction and exploitation of the Chippewa people. Both volumes understand the United States to be preoccupied with imperialist impulses. Even as they critique such projects, they also point to the tenacity with which individuals encounter these systems, and they do so by creating “interstitial temporalities,” which allow them to navigate time at the crossroads of language and culture.

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