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Full-Text Articles in Life Sciences

Linking The Green And Brown Worlds: The Prevalence And Effect Of Multichannel Feeding In Food Webs, Elizabeth M. Wolkovich, Stefano Allesina, Kathryn L. Cottingham, John C. Moore, Stuart A. Sandin, Claire De Mazancourt Dec 2014

Linking The Green And Brown Worlds: The Prevalence And Effect Of Multichannel Feeding In Food Webs, Elizabeth M. Wolkovich, Stefano Allesina, Kathryn L. Cottingham, John C. Moore, Stuart A. Sandin, Claire De Mazancourt

Dartmouth Scholarship

Recent advances in food‐web ecology highlight that most real food webs (1) represent an interplay between producer‐ and detritus‐based webs and (2) are governed by consumers which are rampant omnivores; feeding on varied prey across trophic levels and resource channels. A possible avenue to unify these advances comes from models demonstrating that predators feeding on distinctly different channels may stabilize food webs. Empirical studies suggest many consumers engage in such behavior by feeding on prey items from both living‐autotroph (green) and detritus‐based (brown) webs, what we term “multichannel feeding,” yet we know little about how common such feeding is across …


Collapse Of An Ecological Network In Ancient Egypt, Justin Yeakel, Mathias Pires, Lars Rudolf, Nathaniel Dominy Oct 2014

Collapse Of An Ecological Network In Ancient Egypt, Justin Yeakel, Mathias Pires, Lars Rudolf, Nathaniel Dominy

Dartmouth Scholarship

The dynamics of ecosystem collapse are fundamental to determining how and why biological communities change through time, as well as the potential effects of extinctions on ecosystems. Here, we integrate depictions of mammals from Egyptian antiquity with direct lines of paleontological and archeological evidence to infer local extinctions and community dynamics over a 6,000-y span. The unprecedented temporal resolution of this dataset enables examination of how the tandem effects of human population growth and climate change can disrupt mammalian communities. We show that the extinctions of mammals in Egypt were nonrandom and that destabilizing changes in community composition coincided with …


Natural Selection On Thermal Performance In A Novel Thermal Environment, Michael L. Logan, Robert M. Cox, Ryan Calsbeek Sep 2014

Natural Selection On Thermal Performance In A Novel Thermal Environment, Michael L. Logan, Robert M. Cox, Ryan Calsbeek

Dartmouth Scholarship

Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation …


Ecological Biogeography Of The Terrestrial Nematodes Of Victoria Land, Antarctica, Byron Adams, Diana Wall, Ross Virginia, Emma Broos, Matthew A. Knox Jun 2014

Ecological Biogeography Of The Terrestrial Nematodes Of Victoria Land, Antarctica, Byron Adams, Diana Wall, Ross Virginia, Emma Broos, Matthew A. Knox

Dartmouth Scholarship

The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species …


Host Use Patterns By The European Woodwasp, Sirex Noctilio, In Its Native And Invaded Range, Matthew P. Ayres, Rebeca Pena, Jeffrey A. Lombardo, Maria J. Lombardero Mar 2014

Host Use Patterns By The European Woodwasp, Sirex Noctilio, In Its Native And Invaded Range, Matthew P. Ayres, Rebeca Pena, Jeffrey A. Lombardo, Maria J. Lombardero

Dartmouth Scholarship

Accelerating introductions of forest insects challenge decision-makers who might or might not respond with surveillance programs, quarantines, eradication efforts, or biological control programs. Comparing ecological controls on indigenous vs. introduced populations could inform responses to new introductions. We studied the European woodwasp, Sirex noctilio, which is not a pest in its native forests, is a serious invasive pest in the southern hemisphere, and now has an uncertain future in North America after its introduction there. Indigenous populations of S. noctilio (in Galicia, Spain) resembled those in New York in that S. noctilio were largely restricted to suppressed trees that …


Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon Jan 2014

Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon

Dartmouth Scholarship

Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates’ slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates’ slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that …