Article Abstract:
Genetic and environmental components of phenotypic variation in body size and immune response of Delichon urbia (the house martin), a colonial, highly social bird in southern Europe. To separate the two factors, a partial cross-fostering experiment was carried out by exchanging half of the offspring of pairs of nests after hatching. No significant additive variance was seen in immune response parameters. Significant environmental variance was seen. Highly social species have limited room for immediate microevolutionary response to selection.
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Article Abstract:
Recent studies of avian sex ratios are reviewed with a discussion of two reasons for sex allocation theory and its success's in predicting sex ratios in such taxa as parasitoid wasps being cited frequently as one of the greatest achievements of theoretical evolutionary biology. Until molecular genetic techniques were developed it was hard to get avian sex ratio data before substantial offspring mortality, and the theory and data needed to predict sex allocation patterns in vertebrates are complex and difficult to get.
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Article Abstract:
Research has been conducted on steelhead alevins. The authors have investigated the potential for genetic modification of steelhead populations affected by highly toxic methylmercury, and report the results.
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