P elements are transposable elements found in P strain, but usually not in M strain, Drosophila melanogaster, and are responsible for the hybrid dysgenesis that occurs when male D. melanogaster of the P strain mate with females of the M strain (ref. 1 and references therein). Several P elements, which vary in length and genetic effects, have now been… (More)
High rates of amino-acid sequence evolution have sometimes been considered to be diagnostic for genes undergoing adaptive change. However, two recent studies have shown that rapid evolution of amino-acid sequence can also be congruent with neutrality.
The human genome contains a set of minisatellites, each of which consists of tandem repeats of a DNA segment containing the 'core' sequence, a putative recombination signal in human DNA. Multiallelic variation in the number of tandem repeats occurs at many of these minisatellite loci. Hybridization probes consisting of tandem repeats of the core sequence… (More)
To answer that, we first need to look at the kinds of genetic changes that have previously been studied by medical geneticists. These have usually been 'single-gene disorders' , which result from mutations in single genes, where an individual with a mutant allele of the gene (in the homozygous state for a recessive disorder) has the disease with a hundred… (More)
The draft of the human genome project reveals an unexpected distribution of Alu interspersed repetitive sequences . This has been interpreted as evidence that Alu sequences 'may benefit their human hosts'  and that they 'have a positive function' . The implication is that the majority of Alu sequences increase the Darwinian fitness of their… (More)
An unexpectedly large proportion of eukaryotic genes yield no obvious mutant phenotype when inactivated. An ingenious new approach using yeast allows all genes to be screened simultaneously for the presence of weak selection against lack-of-function mutations.
Advances in data analysis and smooth non-linear modelling techniques enable the construction of accurate short range predictions for high dimensional chaotic systems. The techniques are illustrated using sunspot data. The ability to construct short/medium range predictions for chaotic dynamics also enables such systems to be controlled and some applications… (More)
Laboratory evolution in Escherichia coli has revealed that fitness typically increases in experimental populations. These changes are sometimes associated with changes in insertion sequence positions, some of which may themselves cause advantageous phenotypes. We have a novel and general method for identifying genes in Escherichia coli, whose knockout by… (More)
Budding yeast provides a useful resource for studies of gene function. A new analysis of the fitness effects of deletion mutations in budding yeast reveals that genes that have duplicates create lower fitness losses when inactivated than do genes that are singletons.