George R. Harper

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Batesian mimicry evolves when a palatable species, the “mimic,” resembles a dangerous species, the “model,” because both receive protection from predation. Yet, this protection should break down where the model is absent, because predators in such areas would not be under selection to avoid the model. Here, we test this prediction in a coral snake mimicry(More)
Contact activation of the intrinsic pathway of porcine blood plasma coagulation is shown to be a steep exponential-like function of procoagulant surface energy, with low activation observed for poorly water-wettable surfaces and very high activation for fully water-wettable surfaces. Test procoagulants studied were a system of oxidized polystyrene films(More)
Predators typically avoid dangerous species, and batesian mimicry evolves when a palatable species (the 'mimic') co-opts a warning signal from a dangerous species (the 'model') and thereby deceives its potential predators. Because predators would not be under selection to avoid the model and any of its look-alikes in areas where the model is absent (that(More)
We developed nine polymorphic microsatellite markers for the Mexican spadefoot toad, Spea multiplicata. Allele numbers range from five to 12, with observed heterozygosities from 0.48 to 0.87. Because two loci are in linkage disequilibrium, these nine loci provide eight independent markers. Three loci exhibit departure from Hardy-Weinberg equilibrium,(More)
Any fish species that appears to be readily available in the marketplace will create an impression among the public that there is a plentiful supply of that fish in the sea, but this may belie the true state of the fisheries' stock. Here we use molecular genetic analysis to show that some three-quarters of the fish sold in the United States as 'red(More)
Batesian mimics-benign species that predators avoid because they resemble a dangerous species-often vary geographically in resemblance to their model. Such geographical variation in mimic-model resemblance may reflect geographical variation in model abundance. Natural selection should favour even poor mimics where their model is common, but only good mimics(More)
Studies of differences or changes in venom protein levels or enzymatic activities have significance only if contrasted to the normal variations between individual snakes. This study involves the analysis and comparison of venom from 13 individual Texas coralsnakes (Micrurus tener tener) in order to detect differences in the volume, total protein(More)
Coralsnakes produce highly potent neurotoxic venoms, but little is known about variations in specific enzyme components within a species or from one replenishment of venom to the next within the same animal. Since published studies are often conducted using venom pools from multiple snakes, individual differences are masked and variations among individual(More)
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