Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Life Sciences

Panoramic Spatial Vision In The Bay Scallop Argopecten Irradians, Daniel R. Chappell, Tyler M. Horan, Daniel Isaac Speiser Nov 2021

Panoramic Spatial Vision In The Bay Scallop Argopecten Irradians, Daniel R. Chappell, Tyler M. Horan, Daniel Isaac Speiser

Faculty Publications

We have a growing understanding of the light-sensing organs and light-influenced behaviours of animals with distributed visual systems, but we have yet to learn how these animals convert visual input into behavioural output. It has been suggested they consolidate visual information early in their sensory-motor pathways, resulting in them being able to detect visual cues (spatial resolution) without being able to locate them (spatial vision). To explore how an animal with dozens of eyes processes visual information, we analysed the responses of the bay scallop Argopecten irradians to both static and rotating visual stimuli. We found A. irradians distinguish between …


Betting & Hierarchy In Paleontology, Leonard Finkelman Jan 2019

Betting & Hierarchy In Paleontology, Leonard Finkelman

Faculty Publications

In his Rock, Bone, and Ruin: An Optimist’s Guide to the Historical Sciences, Adrian Currie argues that historical scientists should be optimistic about success in reconstructing the past on the basis of future research. This optimism follows in part from examples of success in paleontology. I argue that paleontologists’ success in these cases is underwritten by the hierarchical nature of biological information: extinct organisms have extant analogues at various levels of taxonomic, ecological, and physiological hierarchies, and paleontologists are adept at exploiting analogies within one informational hierarchy to infer information in another. On this account, fossils serve the role …


Ordination Obscures The Influence Of Environment On Plankton Metacommunity Structure, Tad Dallas, Andrew M. Kramer, Marcus Zokan, John M. Drake Nov 2016

Ordination Obscures The Influence Of Environment On Plankton Metacommunity Structure, Tad Dallas, Andrew M. Kramer, Marcus Zokan, John M. Drake

Faculty Publications

The composition of plankton communities in individual habitats is often influenced by environmental conditions like pH or hydroperiod. At larger scales, environmental gradients can influence community structure across interconnected local communities. Detecting the role of environmental and spatial factors on metacommunity structure depends on the ordering of sites and species prior to analysis. We investigated this ordination in two wetland metacommunities; a well-sampled, hyper-diverse zooplankton metacommunity, and a Central American phytoplankton metacommunity. We calculated coherence, turnover, and boundary clumping to classify the structure of the metacommunity, and we propose a statistic that responds to variation in both coherence and turnover. …


Co-Extinction In A Host-Parasite Network: Identifying Key Hosts For Network Stability, Tad Dallas, Emily Cornelius Aug 2015

Co-Extinction In A Host-Parasite Network: Identifying Key Hosts For Network Stability, Tad Dallas, Emily Cornelius

Faculty Publications

Parasites comprise a substantial portion of total biodiversity. Ultimately, this means that host extinction could result in many secondary extinctions of obligate parasites and potentially alter hostparasite network structure. Here, we examined a highly resolved fish-parasite network to determine key hosts responsible for maintaining parasite diversity and network structure (quantified here as nestedness and modularity). We evaluated four possible host extinction orders and compared the resulting co-extinction dynamics to random extinction simulations; including host removal based on estimated extinction risk, parasite species richness and host level contributions to nestedness and modularity. We found that all extinction orders, except the one …


Population Responses Of Wood Frog (Rana Sylvatica) Tadpoles To Overwintered Bullfrog (Rana Catesbeiana) Tadpoles, Leroy J. Walston, Stephen J. Mullin Jan 2007

Population Responses Of Wood Frog (Rana Sylvatica) Tadpoles To Overwintered Bullfrog (Rana Catesbeiana) Tadpoles, Leroy J. Walston, Stephen J. Mullin

Faculty Publications

A fundamental goal in ecology is to understand how environmental variation influences the distribution of individuals within a population. In this study, we used laboratory experiments to examine the population responses of sympatric Wood Frog (Rana sylvatica) tadpoles to native overwintered Bullfrog (Rana catesbeiana) tadpoles. For periods of up to two weeks, we measured growth, activity, and refuge use of Wood Frog tadpoles in small mesocosms with and without an overwintered Bullfrog tadpole present. Bullfrog tadpoles had a negative effect on the growth of Wood Frog tadpoles allotopic (naive) to Bullfrogs, whereas the presence of Bullfrogs had no effect on …