The authors present the structure and functions of the Veterinary Public Health Services in Australasia and the Pacific Islands. Services in the region range from the extensive and highly developed organisations of Australia and New Zealand to those meeting the needs of the subsistence agriculture economies of some of the smaller island groups. Geographic isolation and strict quarantine measure...

There is large variation in the genetic diversity among the African cattle (MNA = 3.73-7.40; AE = 1.92-3.91; HE = 0.478-0.744). In pooled geographic region samples, diversity is highest in the North African Bos taurus and it is lowest in the western part of the continent. Genetic structure analysis support isolation by distance in all, but the Southern African region, with extensive gene flow b...

BACKGROUND In a species with a large distribution relative to its dispersal capacity, geographic variation in traits may be explained by gene flow, selection, or the combined effects of both. Studies of genetic diversity using neutral molecular markers show that patterns of isolation by distance (IBD) or barrier effect may be evident for geographic variation at the molecular level in amphibian ...

Mitochondrial DNA sequences isolated from ancient dog remains from Latin America and Alaska showed that native American dogs originated from multiple Old World lineages of dogs that accompanied late Pleistocene humans across the Bering Strait. One clade of dog sequences was unique to the New World, which is consistent with a period of geographic isolation. This unique clade was absent from a la...

Most models of speciation require gradual change and geographic or ecological isolation for new species to arise. Homoploid hybrid speciation occurred readily between Saccharomyces cerevisiae and Saccharomyces paradoxus. Hybrids had high self-fertility (about 82%), low fertility when backcrossed to either parental species (about 7.5%), and vigorous growth under different thermal environments th...

The mature larva of a new species, Neoephemera projecta sp. n., from China is described in detail. It represents a new country record of the genus for China. The discovery shows that the genus Neoephemera McDunnough has a more extensive Holarctic distribution than previously known. Ecological vicariance instead of geographic isolation is therefore favoured as presumed cause of the origin of the...

We propose an extended genetic algorithm (GA) with different local environmental conditions. Genetic entities, or configurations, are put on nodes in a ring structure, and location-dependent conditions applied for each entity. Our GA is motivated by the geographic aspect of natural evolution: Geographic isolation reduces diversity group, but at same time, can enhance intergroup diversity. Matin...

Discerning the relative roles of adaptive and nonadaptive processes in generating differences among populations and species, as well as how these processes interact, is a fundamental aim in biology. Both genetic and phenotypic divergence across populations can be the product of limited dispersal and gradual genetic drift across populations (isolation by distance), of colonization history and fo...

Metapopulation theory is one of the most popular approaches to identify the factors affecting the spatial and temporal dynamics of populations in fragmented habitat networks. Habitat quality, patch area and isolation are mainly focused on when analyzing distribution patterns in fragmented landscapes. The effects of landscape heterogeneity in the non-occupied matrix, however, have been largely n...

Studies of behavioral isolation among geographically isolated populations of Drosophila mojavensis have provided an understanding of incipient speciation wherein phylogeny and ecology play a prominent role. Populations of D. mojavensis in mainland Mexico and southern Arizona exhibit low but significant premating isolation from Baja California populations in laboratory mate choice tests. These s...