Article Abstract:
Effects of supernumerary heterochromatin on chromosome segregation and chiasma formation in Dociostaurus genei (Orthoptera), a grasshopper for which most of the autosomes present polymorphisms for distal heterochromatic supernumerary segments, are discussed. The methods used show supernumerary segments are associated with two major effects, a higher content of supernumerary heterochromatin correlates wit the formation of a lower number of chiasmata in a chromosome complement and distal segments are truly terminal.
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Article Abstract:
Population disjunction on isozyme variation and its effects have been studied in the widespread Pilgerodendron uviferum. It was concluded that total range, along with information on the degree of among-population isolation, may be a better predictor of levels of polymorphism than range size by itself. In 20 populations along the total range, eleven of the 14 putative genetic loci were polymorphic in at least one population and six of them were polymorphic in more than one population.
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Article Abstract:
Possible effects of chromosome and morphometric variables on male mating success in Leptysma argentina (Orthoptera), a South American grasshopper, has been studied using univariate and multivariate methods. Results are considered relative to previous knowledge of natural selection acting on other fitness components in the species.
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