No abstract

No abstract

Several regions of the human genome are highly variable in populations because the number of repeats in these regions of a short 'minisatellite' sequence varies at high frequency. Different minisatellites have a core sequence in common, however, and probes made up of tandem repeats of this core sequence detect many highly variable DNA fragments in several species including humans, cats, dogs and mice. The hypervariable sequences detected in this way are dispersed in the genome and their variability means that they can be used as a DNA 'fingerprint', providing a novel method for the identification of individuals, confirmation of biological relationships and human genetic analysis. We show here that human minisatellite-derived probes also detect highly variable regions in bird DNAs. Segregation analysis in a house sparrow family confirms that these regions comprise many mostly heterozygous dispersed loci and we conclude that house sparrow DNA fingerprints are analogous to those of humans. Fingerprint analysis identified one nestling, with fingerprint bands not present in the parent pair's fingerprints, which we conclude resulted from an extrapair copulation. Extrabond copulations have been described in many wild bird species, but their success and hence adaptive significance have rarely been quantifiable. DNA fingerprinting will be of great significance to studies of the sociobiology, demography and ecology of wild birds.

In the past decade much attention has focused on the role that genetics can play in the formation of management strategies in conservation. Here, we describe genetic diversity in the world's largest lizard, the Komodo dragon (Varanus komodoensis), examining the evolutionary relationships and population genetic history of the four islands in southeast Indonesia, which form the vast majority of its range. We identify distinct genetic groups for conservation. The population on the island of Komodo shows by far the largest values of genetic divergence and is proposed that it should be a separate conservation management unit. Other populations, surviving either on small islands with substantially reduced genetic variability, or in isolated patches, are identi¢ed as particularly vulnerable to stochastic threats and habitat loss. Our results provide an example of how data de¢ning intraspeci¢c levels of genetic divergence can provide information to help management plans, ensure the maintenance of genetic variability across populations and identify evolutionary potential within endangered species.

The evolutionary basis of domestication has been a longstanding question and its genetic architecture is becoming more tractable as more domestic species become genome-enabled. Before becoming established worldwide, sheep and goats were domesticated in the fertile crescent 10,500 years before present (YBP) where their wild relatives remain. Here we sequence the genomes of wild Asiatic mouflon and Bezoar ibex in the sheep and goat domestication center and compare their genomes with that of domestics from local, traditional, and improved breeds. Among the genomic regions carrying selective sweeps differentiating domestic breeds from wild populations, which are associated among others to genes involved in nervous system, immunity and productivity traits, 20 are common to Capra and Ovis. The patterns of selection vary between species, suggesting that while common targets of selection related to domestication and improvement exist, different solutions have arisen to achieve similar phenotypic end-points within these closely related livestock species.