The frequency and strength with which selection shapes patterns of genetic variation is unknown. Whereas all loci should be roughly equally affected by demography and population history, selected loci may exhibit increased or decreased genetic differentiation relative to neutral loci (Cavalli-Sforza 1966). Thus, one way to test for selection on a specific category of loci is to compare geograph...

The extent and spatial patterns of genetic variation at allozyme markers were investigated within and between diploid and autotetraploid knapweeds (Centaurea jacea L. sensu lato, Asteraceae) at contrasted geographic scales: (1) among populations sampled from a diploid-tetraploid contact zone in the northeastern part of the Belgian Ardennes, and (2) within mixed populations from that zone where ...

We examined genetic differentiation among seven populations of limber pine using four classes of gene marker. Among-population differentiation was much higher for maternally inherited mitochondrial DNA polymorphisms than for paternally inherited chloroplast DNA, indicating that wind-dispersed pollen is the main agent of gene flow. Chloroplast DNA differentiation is consistent with gene flow est...

Monoecy and protogyny are widespread in wind-pollinated plants and have been interpreted as outcrossing mechanisms, though few studies have investigated their function. Carex, a large genus of anemophilous herbs, is predominantly monoecious and many species are protogynous. We investigated whether monoecy and protogyny limit self-pollination in seven Carex species. We conducted field experiment...

Patterns of H-2 and allozyme polymorphism in natural populations of house mice from Europe, North Africa and South America were analyzed. The purpose of the analysis was to determine whether H-2 and allozyme polymorphisms were similarly distributed both geographically and temporally in wild mice. Two subspecies of house mice, Mus musculus domesticus and M. m. musculus were sampled and the polym...

Morphologically identified Anopheles flavirostris (Diptera: Culicidae), the principal malaria vector in the Philippines, comprised two species in collections from the Bataan Province of Luzon based on allozyme and internal transcribed spacer 2 ribosomal DNA analysis. Seven percent of morphologically identified specimens were the closely related nonvector An. filipinae. Morphologic variability o...

ABSTRACT Sixty Ecuadorian isolates of Phytophthora infestans from potato and 60 isolates from tomato were compared for dilocus allozyme genotype, mitochondrial DNA haplotype, mating type, and specific virulence on 11 potato R-gene differential plants and four tomato cultivars, two of which contained different Ph genes. Restriction fragment length polymorphism (RFLP) fingerprints of subsamples o...