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101.
Christine E. Thacker Andrew R. Thompson Dawn M. Roje Emily Y. Shaw 《Marine Biology》2008,153(3):375-385
Species of the reef goby genus Gnatholepis exhibit enormous geographic ranges with little evidence of population segregation detectable based on mitochondrial DNA.
To determine if genetic differentiation is evident with more rapidly evolving markers, seven microsatellite loci were screened
from the species Gnatholepis anjerensis and G. scapulostigma and population segregation was tested among fish from across the South Pacific. Both AMOVA and pairwise F
ST analyses showed that, in concordance with previous mitochondrial results, most genetic variance occurs within individual
populations, as population differentiation is evident only over the largest distances (>3,700 km). This result is contrasted
with previous studies demonstrating that despite their relatively long larval periods, some gobiid fishes exhibit population
differentiation on small (<100 km) geographic scales. Coalescence analysis showed that current Pacific populations of these
species originated in the Pleistocene, presumably related to sea level fluctuations associated with episodes of glaciation.
However, rate analysis based on a phylogeny of Gnatholepis species indicates that the species themselves are much older, consistent with a complex history of rapid, short-term population
contractions and expansions, with corresponding rapid dispersal. 相似文献
102.
Patterns of mtDNA diversity in North Atlantic populations of the mussel Mytilus edulis 总被引:3,自引:3,他引:0
Patterns of (female) mitochondrial DNA diversity were investigated in the blue mussel Mytilus edulis. Mytilus edulis is a ubiquitous member of contemporary North Atlantic hard-substrate communities and well represented in studies of this
region. Mytilus edulis was surveyed in North America and Europe, as well as mid-Atlantic sites in Greenland, Iceland, and the Faroe Islands. Mitochondrial
DNA sequences revealed considerable population structure but no monophyly of haplotypes between any major regions. Coalescent
analyses suggest that migration across the Atlantic Ocean has prominently been from North American source populations and
that Greenland was colonized recently and exclusively from North America. In North America, there was support for two regional
groups along the North American coastline. Surprisingly, we also found evidence of recombination between some Mytilus edulis and Mytilus galloprovincialis female mtDNA sequences, particularly in northern Europe.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
An erratum to this article can be found at 相似文献
103.
Christine R. Maher 《Behavioral ecology and sociobiology》2009,63(6):857-868
Solitary species show several patterns of space use and relatedness. Individuals may associate randomly or may live near female
or male kin, often as a result of natal philopatry or dispersal patterns. Although usually described as solitary or asocial,
woodchucks (Marmota monax) are behaviorally flexible marmots that exhibit greater sociality in some populations than others. I examined relationships
between kinship, geographic distance, and home range overlap, as well as dispersal and philopatry, to determine the extent
to which kin associated spatially. I used a combination of microsatellite DNA analysis, long-term behavioral observations,
and radiotelemetry to test predictions that females, but not males, would associate with kin. Indeed, woodchucks lived closer
and shared a greater proportion of their home range with more closely related animals. Overlap of females' and males' home
ranges was positively correlated with kinship, and male–female dyads shared more area with closer kin. Most juveniles delayed
dispersal beyond their first summer. Females often remained philopatric and settled near their natal range. Although males
often dispersed as yearlings, some males also established territories within or immediately adjacent to their natal home ranges.
A combination of factors can explain these spatial patterns, including high population density associated with the study site's
location within a suburban environment, high dispersal costs, and abundant food. Thus, despite their asocial and solitary
reputation, woodchucks displayed spatial patterns seen in other, more social species of ground-dwelling sciurids. 相似文献
104.
Christine L. Jocoy 《Journal of the American Water Resources Association》2000,36(4):811-821
ABSTRACT: Research on the condition of drinking water provision in the United States documents the inequitable financial impact of environmental regulations on small water systems (those serving 3,300 or fewer people). While a variety of federal and state financial assistance programs are available for water systems, few quantitative analyses have evaluated the success of these programs in alleviating the problems of small systems. A case study of the largest aid initiative for water supply infrastructure in Pennsylvania provides the empirical framework through which to analyze government funding opportunities for water systems. This study examines the allocation practices of the Pennsylvania Infrastructure Investment Authority (PENNVEST) to water systems of varying sizes. Utilizing data from PENNVEST applications and the Pennsylvania Department of Environmental Protection, the distribution of PENNVEST award recipients and denied applicants by size characteristics are compared. The study indicates that very small water systems (those serving 500 or fewer) do not apply for or receive funds with the same frequency as their larger counterparts. Understanding the allocation of awards from PENNVEST offers insight into the ability of small communities to access capital for water supply infrastructure. 相似文献
105.
By using dialysis equilibrium experiments, the sorption of a branched nonylphenol isomer [4-(1-ethyl-1,3-dimethylpentyl)-phenol] (NP111) on various humic acids (HAs) isolated from river sediments and two reference HAs was studied. The HAs were characterized by solid-state 13C direct polarization/magic angle spinning nuclear magnetic resonance (13C DP/MAS NMR) spectroscopy. Sorption isotherms of NP111 on HAs were described by a linear model. The organic carbon-normalized sorption coefficient (KOC) ranged from 2.3 × 103 to 1.5 × 104 L kg−1. Interestingly, a clear correlation between KOC value and alkyl C content was observed, indicating that the aliphaticity of HAs markedly dominates the sorption of NP111. These new mechanistic insights about the NP111 sorption indicate that the fate of nonylphenols in soil or sediment depends not only on the content of HA, but also on its structural composition. 相似文献
106.
Christine E. Wilkinson Alex McInturff Jennifer R. B. Miller Veronica Yovovich Kaitlyn M. Gaynor Kendall Calhoun Harshad Karandikar Jeff Vance Martin Phoebe Parker-Shames Avery Shawler Amy Van Scoyoc Justin S. Brashares 《Conservation biology》2020,34(4):854-867
Carnivore predation on livestock is a complex management and policy challenge, yet it is also intrinsically an ecological interaction between predators and prey. Human–wildlife interactions occur in socioecological systems in which human and environmental processes are closely linked. However, underlying human–wildlife conflict and key to unpacking its complexity are concrete and identifiable ecological mechanisms that lead to predation events. To better understand how ecological theory accords with interactions between wild predators and domestic prey, we developed a framework to describe ecological drivers of predation on livestock. We based this framework on foundational ecological theory and current research on interactions between predators and domestic prey. We used this framework to examine ecological mechanisms (e.g., density-mediated effects, behaviorally mediated effects, and optimal foraging theory) through which specific management interventions operate, and we analyzed the ecological determinants of failure and success of management interventions in 3 case studies: snow leopards (Panthera uncia), wolves (Canis lupus), and cougars (Puma concolor). The varied, context-dependent successes and failures of the management interventions in these case studies demonstrated the utility of using an ecological framework to ground research and management of carnivore–livestock conflict. Mitigation of human–wildlife conflict appears to require an understanding of how fundamental ecological theories work within domestic predator–prey systems. 相似文献
107.
108.
Chang-Hee Christine Bae 《Journal of Environmental Planning and Management》1997,40(2):235-260
This paper examines how air pollution control policies will affect the welfare of the different races in Southern California. The paper adopts the concept of the Net Welfare Impact (NWI) function to measure how air quality improvements affect the welfare (monetary and non-monetary) of individual households. The core finding is that many of the benefits of air quality improvement are enjoyed by minorities, especially Latinos (and African-Americans and Asians to a lesser extent), whose household incomes tend to be lower and family size larger than the regional average, and who are more likely to live in the neighbourhoods that are currently polluted. Thus, because minorities have suffered more from dirty air, they are the major beneficiaries from implementation of clean air policies. This is the result of the Federal clean air mandate that dictates uniform standards for all metropolitan areas. 相似文献
109.
Christine A. Matthews 《Journal of the American Water Resources Association》1991,27(5):841-847
ABSTRACT: Southern California, now in its fifth consecutive year of drought, has always relied heavily on imported water from the Owens Valley, the State Water Project, and the Colorado River. For various reasons, these sources are now decreasing and water suppliers are being forced to look for new sources. One possible alternative is to store water obtained during peak supply periods for use during dry periods in ground water storage basins. The Santa Ana River Basin in Orange County has already been developed, and is being used to provide water to 25 cities in Orange County. The San Juan Basin, also in Orange County, is being studied as a possible future storage basin. This paper examines some of the positive and negative aspects of developing and using ground water storage basins in Southern California. 相似文献
110.
Blasing T. J. Broniak Christine Marland Gregg 《Mitigation and Adaptation Strategies for Global Change》2005,10(4):659-674
Time series of fossil fuel carbon emissions from 1960–2000 for each of the U.S. states and the District of Columbia are presented
and discussed. Comparison of the nationally summarized results with other national datasets shows generally good agreement,
usually within 2%, and gives insight into the quality of all the data series. Our extension of the state-by-state emissions
estimates back to 1960 reveals patterns of change that are coherent across states and can be related to historic events such
as energy crises and federal legislation. Most notable is the changing pattern of coal usage, as coal-producing states produce
increasingly more energy (mostly for electricity) for other states so that per capita CO2 emissions diverge for states that import as opposed to those that export electricity. The decline in carbon emissions from
petroleum products following the 1970s is also evident. Per capita emissions range over an order of magnitude for the different
states. The data suggest that differences in per capita emissions arise from differences in many technological, physical,
resource, social, and economic factors. The data presented here and the few correlations briefly noted pose a challenge for
trying to use per capita emissions as a measure of equity or to provide mitigation targets. 相似文献