NSF awards 'Life in Transition' grants to University of Oklahoma ...( The connection among living systems ...)

The connection among living systems and earth's history is the focus of National Science Foundation grants awarded to University of Oklahoma zoology professor Lawrence Weider and botany and microbiology research assistant professor Amy V. Callaghan.

Weider and colleagues will investigate how aquatic organisms, especially the water flea, Daphnia, cope with drastically altered environments caused by nutrient pollution. The study is the first of its type and targets lakes inCanada and Minnesota where Daphnia diapausing eggs have laiddormant for more than 50 years. The researchers will compare the effects of phosphorus on aquatic life today vs. that of 50 years ago by hatching out the eggs and comparing changes in their physiology and genetic structure.

Weider and collaborators will use "resurrection ecology" methods to examine how lakes and ponds enriched with nutrients such as phosphorus influence microevolutionary change in organisms, such as Daphnia. Resurrecting long-dormant decades-old eggs from lake sediments will allow testing to determine how microevolutionary changes in response to nutrient enrichment occurred during the past century.

In his laboratory at the OU Biological Station, Weider will study the effects of long-term pollution on aquatic ecosystems while providing valuable information on how organisms evolve in natural environments in collaboration with Punidan Jeyasingh, assistant professor of zoology at Oklahoma State University and colleagues at Indiana University. The total budget for the three-year project is $780,000.

Callaghan's research focuses on sulfate-reducing bacteria that utilize petroleum hydrocarbons as growth substrates. Alkanes, which are important components of petroleum, were traditionally considered to be biologically inert in the absence of oxygen. However, microorganisms have evolved unique ways of activating alkanes anaerobically. Thesemechanisms have recently been discovered and play
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