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Full-Text Articles in Biology

Biology: What One Needs To Know, Ursula Goodenough Dec 1996

Biology: What One Needs To Know, Ursula Goodenough

Biology Faculty Publications & Presentations

Biology on this planet represents an astonishing experiment in carbon-based chemistry which, over billions of years, has generated billions of species adapted to countless major and minor fluctuations in ecological circumstances. In one sense there is no way to generalize about biology. While biological activities can all be ultimately explained by physical laws (like everything else in the universe), it is the emergent intensely particular properties of organisms that most interest us. This essay represents an attempt to describe some of the more prominent patterns that emerge from the sea of biological particularities, patterns that present many opportunities for religious …


Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin Oct 1996

Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin

Faculty Publications

In marine soft-sediment habitats, the sediment surface is altered by activities of sediment dwellers (infauna). Such biogenic disturbance can influence recruitment success if settling larvae and juveniles avoid disturbed sites or if juveniles die as a result of disturbance after settling. Because infauna commonly lose exposed body parts to browsing predators and disturb less sediment as a result, we developed a simulation model to examine the interactions between browsing predation, infaunal adult activity, and recruitment. Sediment disturbance in the model was based on data for the polychaete Abarenicola pacifica. We simulated the activity of two general types of predators: prey …


Abundant Protein-Containing Particles In The Sea, Richard A. Long, Farooq Azam Jun 1996

Abundant Protein-Containing Particles In The Sea, Richard A. Long, Farooq Azam

Faculty Publications

The interaction of bacteria with particulate organic matter has implications for organic matter cycling and bacterial ecology in the ocean. Until recently, the focus has been on 'classical' particles visible by unaided eye (marine snow) or light microscopy. Recent discoveries of several new types of abundant particles, from sub-micrometer to sub-marine snow, are changing our ideas of the physical and chemical nature of the particle field with which pelagic bacteria interact. Previous workers have discovered polysaccharide-containing (Alcian Blue stainable) transparent exopolymer particles (TEP) ranging from 3 to 100s of micrometers. Looking for additional components of the sub-marine snow particle field, …


Settlement And Early Post-Settlement Survival Of Sessile Marine Invertebrates On Topographically Complex Surfaces: The Importance Of Refuge Dimensions And Adult Morphology, Linda J. Walters, David S. Wethey Jun 1996

Settlement And Early Post-Settlement Survival Of Sessile Marine Invertebrates On Topographically Complex Surfaces: The Importance Of Refuge Dimensions And Adult Morphology, Linda J. Walters, David S. Wethey

Faculty Publications

We predicted that both refuge dimension and growth form would influence settlement and short-term post-settlement success (≤7 d) of sessile marine invertebrates that live attached to hard substrata in low energy environments. Individuals with unlimited attachment to the substrata should rapidly be protected by their growth form, thus decreasing their need to settle in refuges and limiting the length of time any locations on heterogeneous substrata act as refuges. Alternatively, organisms with limited attachment to the substrata should remain susceptible to the causes of mortality for a longer time, and as a result should settle in high quality refuges (sites …


Effects Of High-Molecular-Weight Dissolved Organic Matter On Nitrogen Dynamics In The Mississippi River Plume, Wayne S. Gardner, Ronald Benner, Rainer M.W. Amon, James B. Cotner Jr., Joann F. Cavaletto, Jeffrey R. Johnson Mar 1996

Effects Of High-Molecular-Weight Dissolved Organic Matter On Nitrogen Dynamics In The Mississippi River Plume, Wayne S. Gardner, Ronald Benner, Rainer M.W. Amon, James B. Cotner Jr., Joann F. Cavaletto, Jeffrey R. Johnson

Faculty Publications

The dynamics of N and its interactions with labile dissolved organic C (DOC), bacteria, and phytoplankton were studied to determine potential effects of dissolved organic matter (DOM) and light on N dynamics in surface waters of the Mississippi River (USA) plume in the Gulf of Mexico. Bacterial uptake of added labeled N compounds ( 15NH4+ or 15N-labeled dissolved free amino acids. DFAA) was stimulated more by high-molecular-weight (HMW, >l kDa) DOM than by low-molecular-weight (LMW, < l kDa) DOM. An index that inversely indicated the presence of labile DOC was defined as the fraction of assimilated Amino acid-15N that was Recovered as 15N -Ammonium (ANRA), following the additions of high-levels (4 µM) of 15N -DFAA. …


The Potential For Ontogenetic Vertical Migration By Larvae Of Bathyal Echinoderms, William Jaeckle, Craig M. Young, Michael G. Devin, Suki U.K. Ekaratne, Sophie B. George Jan 1996

The Potential For Ontogenetic Vertical Migration By Larvae Of Bathyal Echinoderms, William Jaeckle, Craig M. Young, Michael G. Devin, Suki U.K. Ekaratne, Sophie B. George

Scholarship

Planktotrophy is a relatively common developmental mode among bathyal and abyssal echinoderms, but the sources of food used by deep-sea planktotrophic larvae remain generally unknown. Very few deep-sea echinoderm larvae have been collected in plankton samples, so we do not know whether larvae migrate to the euphotic zone to feed or if they rely on bacteria or detritus at greater depths. We approached this question indirectly by investigating whether larvae of bathyal echinoids can tolerate the temperatures they would encounter in the euphotic zone and whether they possess sufficient energy stores to migrate to the euphotic zone without feeding. Twenty-four …