SYNOPSIS. Many of the most commonly cited examples of exquisite adaptation are of coevolved symbioses. As we learn more about the coevolutionary process, however, it is becoming increasingly evident that coevolution may also keep populations moderately maladapted much of the time. As a result, coevolving populations may only rarely occupy adaptive peaks, because the selective landscape is under...

Geographic patterns of genetic variation within modern populations, produced by complex histories of migration, can be difficult to infer and visually summarize. A general consequence of geographically limited dispersal is that samples from nearby locations tend to be more closely related than samples from distant locations, and so genetic covariance often recapitulates geographic proximity. We...

Color polymorphism in natural populations can manifest as a striking patchwork of phenotypes in space, with neighboring populations characterized by dramatic differences in morph composition. These geographic mosaics can be challenging to explain in the absence of localized selection because they are unlikely to result from simple isolation-by-distance or clinal variation in selective regimes. ...

Geographic variation in resource use can produce locally adapted populations that exhibit genetic and phenotypic divergence. In the bird-winged grasshopper (Schistocerca emarginata = [lineata]), we investigate whether genetic data exist in accordance with geographic variation in resource (host) use and coloration. In Texas, juvenile grasshoppers feed almost exclusively on one of two host plants...

The cowpea aphid, Aphis craccivora Koch (Hemiptera: Aphididae), is one of the most destructive insect pests of legume plants worldwide. Although outbreaks of this pest occur annually in Thailand causing heavy damage, its genetic structure and demographic history are poorly understood. In order to determine genetic structure and genetic relationship of the geographic populations of this species,...

The aim of this study was to characterize the genetic diversity of domestic goat in China. For this purpose, we determined the sequence of the mitochondrial DNA (mtDNA) control region in 72 individuals of the Yangtze River delta white goat, and reanalysed 723 published samples from 31 breeds/populations across China. All goat haplotypes were classified into four haplogroups (A-D) previously des...

Lutzomyia longipalpis, a sibling complex, is the main vector of Leishmania chagasi/infantum. Discriminating between siblings is important as they may differ in vectorial capacity. Lutzomyia longipalpis populations display distinct male sex pheromone chemotypes. We investigated the phylogeographic pattern of variation at microsatellite loci from 11 populations from Brazil and Venezuela related t...

The genetic variation among 128 isolates of Monilinia fructicola (Fungi, Ascomycota, Helotiales) from China was analyzed using Inter-Simple Sequence Repeat (ISSR) markers and compared with those of samples from California, USA and New Zealand. A total of 72 reproducible DNA fragments were scored, of which 87.5% (63/72) were polymorphic. The Nei's gene diversity and Shannon's diversity indices o...

Advertisement calls tend to differ among populations, based on morphological and environmental factors, or simply geographic distance, in many taxa. Invasive cane toads (Rhinella marina) were introduced to Australia in 1935 and their distribution has expanded at increasing rates over time. Rapid evolution occurred in morphological and behavioural characters that accelerate dispersal, but the ef...

A simultaneous survey of 14 protein loci, together with frequencies and within- and between-population allelism rates of lethal chromosomes, was carried out in five (four Japanese and one Korean) natural populations and one cage population of Drosophila melanogaster. It was found that lethal allelism rates decrease rapidly as geographic distance between two populations increases, while variatio...