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p. 142-162
Received: 30 October 2009 / Accepted: 18 January 2010 / Published: 27 January 2010
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| Download PDF Full-text (487 KB) Abstract: Rapid, global declines among amphibians are partly alarming because many occur for apparently unknown or enigmatic reasons. Moreover, the relationship between phylogeny and enigmatic declines in higher clades of the amphibian phylogeny appears at first to be an intractable problem. I present a working solution by assessing threatening processes potentially underlying enigmatic declines in the family, Hylidae. Applying comparative methods that account for various evolutionary scenarios, I find extreme concentrations of threatening processes, including pollution and habitat loss, in the clade Hylini, potentially influenced by traits under selection. The analysis highlights hotspots of declines under phylogenetic influence in the genera Isthmohyla , Plectrohyla and Ptychohyla , and geographically in Mexico and Guatemala. The conservation implications of concentrated phylogenetic influence across multiple threatening processes are twofold: Data Deficient species of threatened clades should be prioritized in future surveys and, perhaps, a greater vulnerability should be assigned to such clades for further consideration of clade-level conservation priorities.
p. 163-181
Received: 4 December 2009 / Accepted: 25 January 2010 / Published: 1 February 2010
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| Download PDF Full-text (553 KB) Abstract: Behaviorally modern human beings have lived in Amazonia for thousands of years. Significant dynamics in species turnovers due to human-mediated disturbance were associated with the ultimate emergence and expansion of agrarian technologies in prehistory. Such disturbances initiated primary and secondary landscape transformations in various locales of the Amazon region. Diversity in these locales can be understood by accepting the initial premise of contingency, expressed as unprecedented human agency and human history. These effects can be accessed through the archaeological record and in the study of living languages. In addition, landscape transformation can be demonstrated in the study of traditional knowledge (TK). One way of elucidating TK distinctions between anthropic and nonanthropic landscapes concerns elicitation of differential labeling of these landscapes and more significantly, elicitation of the specific contents, such as trees, occurring in these landscapes. Freelisting is a method which can be used to distinguish the differential species compositions of landscapes resulting from human-mediated disturbance vs. those which do not evince records of human agency and history. The TK of the Ka’apor Indians of Amazonian Brazil as revealed in freelisting exercises shows differentiation of anthropogenic from high forests as well as a recognition of diversity in the anthropogenic forests. This suggests that the agents of human-mediated disturbance and landscape transformation in traditional Amazonia encode diversity and contingency into their TK, which encoding reflects past cultural influence on landscape and society over time.
p. 182-206
Received: 4 December 2009 / Accepted: 25 January 2010 / Published: 1 February 2010
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| Download PDF Full-text (592 KB) Abstract: Archaeology is a discipline that can offer a long term perspective on the impacts human societies have had on the environment. Landscape studies are critical for understanding these impacts, because they embrace a dialectical view regarding the relationship between humans and their immediate surroundings. Such studies are well suited to the Amazon basin, a region that has driven much media attention due to astonishing rates of deforestation in certain areas, with likely consequences on the planet’s climate, posing challenges to the survival of the human species for the coming decades. In fact, although much has been said about the impacts of contemporary societies on tropical forest environments, ancient landscape management practices have not yet been considered part of the equation. Thus far, we know that Amerindian societies have been actively transforming their surroundings for millennia. On the eve of European contact, large, complex societies were bringing about long-lasting transformations of landscapes throughout the basin. Conquest and colonization resulted in epidemics, enslavement, and changes to the indigenous economies that managed to survive the genocide. Afterwards, as colonizers would exploit traditional resources leading, in many instances, to their exhaustion, a huge quantity of information on sustainable ways of dealing with certain environments became lost. Traditional knowledge, however, still survives among certain indigenous, peasant (caboclo), and African-Brazilian populations. Documentation of surviving management practices together with the study of the archaeological record could provide valuable information for policy makers. This article examines historical transformations that took place on Marajó Island during the last two millennia and advocates the importance of archaeological research for understanding the historical ecology of landscape change. It is argued that ancient economic strategies, some still being practiced today, could be re-created in the present, since these may constitute opportunities for sustainable sources of income to local communities.
p. 207-232
Received: 31 December 2009 / Accepted: 9 February 2010 / Published: 11 February 2010
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| Download PDF Full-text (283 KB) Abstract: Contrary to common belief, decomposition of diversity into independent richness and evenness components is mathematically impossible. However, richness can be decomposed into independent diversity and evenness or inequality components. The evenness or inequality component derived in this way is connected to most of the common measures of evenness and inequality in ecology and economics. This perspective justifies the derivation of measures of relative evenness, which give the amount of evenness relative to the maximum and minimum possible for a given richness. Pielou’s [1] evenness measure J is shown to be such a measure.
p. 233-255
Received: 24 November 2009 / Accepted: 5 February 2010 / Published: 16 February 2010
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| Download PDF Full-text (1034 KB) Abstract: The area of the Aegean can be described as one of nature’s most active laboratories. The contemporary geomorphology of the Aegean is a result of diverse and still ongoing geological events, which coupled with climate changes, have created mountains and thousands of islands. The Aegean bridges three continents, where human activity has been recorded for at least 10,000 years. Herpetofauna diversity offered early researchers the possibility of describing patterns in the Aegean, especially as the distributional limit for several species and faunal elements. The patterns initially described at a rather coarse scale formed the frame on which the application of new techniques opened new views and permitted finer analyses. Here, we assess recent works on the Aegean’s herpetofauna, outlining the role of sea barriers, especially the Mid Aegean Trench (MAT). We propose four basic patterns (pre-MAT, post-MAT, newcomers, and that of an outlier) and discuss exceptions to these patterns, to interpret the diversity recorded. The interdisciplinary study of taxonomy helps explaining the observed diversity and provides powerful arguments for how exploring diversity can be used to explain more than biological processes.
p. 256-280
Received: 15 December 2009 / Accepted: 22 February 2010 / Published: 24 February 2010
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| Download PDF Full-text (284 KB) Abstract: The origin and subsequent proliferation of malarias capable of infecting humans in South America remain unclear, particularly with respect to the role of Neotropical monkeys in the infectious chain. The evidence to date will be reviewed for Pre-Columbian human malaria, introduction with colonization, zoonotic transfer from cebid monkeys, and anthroponotic transfer to monkeys. Cultural behaviors (primate hunting and pet-keeping) and ecological changes favorable to proliferation of mosquito vectors are also addressed.
p. 281-313
Received: 10 November 2009 / Accepted: 20 February 2010 / Published: 25 February 2010
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| Download PDF Full-text (492 KB) Abstract: As part of an overall decline in biodiversity, populations of many organisms are declining and species are being lost at unprecedented rates around the world. This includes many populations and species of amphibians. Although numerous factors are affecting amphibian populations, we show potential direct and indirect effects of climate change on amphibians at the individual, population and community level. Shifts in amphibian ranges are predicted. Changes in climate may affect survival, growth, reproduction and dispersal capabilities. Moreover, climate change can alter amphibian habitats including vegetation, soil, and hydrology. Climate change can influence food availability, predator-prey relationships and competitive interactions which can alter community structure. Climate change can also alter pathogen-host dynamics and greatly influence how diseases are manifested. Changes in climate can interact with other stressors such as UV-B radiation and contaminants. The interactions among all these factors are complex and are probably driving some amphibian population declines and extinctions.
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