David Ferrell

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Gamete recognition proteins can evolve at astonishing rates and lie at the heart of reproductive isolation and speciation in diverse taxa. However, the source of selection driving this evolution remains unknown. We report on how the sperm bindin genotype influences reproductive success under natural conditions. An interaction between genotype frequency and(More)
In sessile and sedentary organisms, competition for space may have fitness consequences that depend strongly on ecological context. Colonial hydroids in the genus Hydractinia use an inducible defense when encountering conspecifics, and intraspecific competition is common in natural populations, often resulting in complete overgrowth of subordinate(More)
This paper is an early report of our continuing effort to provide a platform-independent framework so that information originators and security administrators can specify access rights to information consistently and completely, and that this specification is then rigorously enforced. To accomplish this objective it is necessary to link a security policy(More)
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