Density and Dispersion in Laboratory Populations of Caddisfly Larvae (Cheumatopsyche, Hydropsychidae)

Ecology ◽  
1969 ◽  
Vol 50 (6) ◽  
pp. 1082-1084 ◽  
Author(s):  
Lynn W. Glass ◽  
Richard V. Bovbjerg
Keyword(s):  
Caddisfly Larvae ◽  
Laboratory Populations

scholarly journals POPULATION GENETICS OF DROSOPHILA AMYLASE. IV. SELECTION IN LABORATORY POPULATIONS MAINTAINED ON DIFFERENT CARBOHYDRATES

Genetics ◽  
1983 ◽  
Vol 103 (4) ◽  
pp. 675-689
Author(s):  
Jeffrey R Powell ◽  
Marko Andjelković
Keyword(s):  
Structural Gene ◽  
Amylase Activity ◽  
Enzyme System ◽  
Specific Expression ◽  
Carbohydrate Source ◽  
Laboratory Populations ◽  
Consistent Change ◽  
Regulation Changes ◽  
Starch Medium

ABSTRACT Two polymorphic systems impinging on α-amylase in Drosophila pseudoobscura have been studied in laboratory populations maintained on medium in which the only carbohydrate source was starch (the substrate of amylase) and replicas maintained on medium in which the only carbohydrate source was maltose (the product of amylase). The two polymorphic systems were alleles at the structural gene (Amy) coding for the enzyme (allozymes) and variation in the tissue-specific expression along the adult midgut controlled by several genes. In the seven populations on maltose medium little consistent change was noted in either system. In the seven populations on starch medium, both polymorphisms exhibited selective changes. A midgut pattern of very limited expression of amylase rose in frequency in all starch populations, as did the frequency of the "fast" (1.00) Amy allele. The overall specific amylase activity did not differ between starch-adapted and maltose-adapted flies.—The results, along with previous studies, indicate that when a gene-enzyme system is specifically stressed in laboratory populations, allozymes often exhibit selective differences. Such results make the selectionist hypothesis at least tenable. Furthermore, the fact that both types of polymorphisms responded to selection indicates the role of structural gene vs. gene regulation changes in adaptive evolution is not an either/or question but one of relative roles and interactions.

scholarly journals Mutation and the evolution of ageing: from biometrics to system genetics

2010 ◽  
Vol 365 (1544) ◽  
pp. 1273-1279 ◽  
Author(s):  
Kimberly A. Hughes
Keyword(s):  
Evolutionary Genetics ◽  
Genetic Networks ◽  
Past Century ◽  
The Past ◽  
Laboratory Populations ◽  
Empirical Tests ◽  
Genetics And Genomics ◽  
Multicellular Organisms ◽  
Modern Population ◽  
Quantitative Explanation

A notable success for evolutionary genetics during the past century was to generate a coherent, quantitative explanation for an apparent evolutionary paradox: the tendency for multicellular organisms to show declining fitness with age (senescence, often referred to simply as ‘ageing’). This general theory is now widely accepted and explains most of the features of senescence that are observed in natural and laboratory populations, but specific instantiations of that theory have been more controversial. To date, most of the empirical tests of these models have relied on data generated from biometric experiments. Modern population genetics and genomics provide new, and probably more powerful, ways to test ideas that are still controversial more than half a century after the original theory was developed. System-genetic experiments have the potential to address both evolutionary and mechanistic questions about ageing by identifying causal loci and the genetic networks with which they interact. Both the biometrical approaches and the newer approaches are reviewed here, with an emphasis on the challenges and limitations that each method faces.

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