Showing papers by "Roger K. Butlin published in 1995"
TL;DR: The geographic mosaic theory of coevolution was proposed by Thompson as mentioned in this paper to understand the development of reciprocal adaptations and specializations in interdependent species, using examples of species interaction from a range of taxa.
Abstract: In this text, Thompson advances a new conceptual approach to the evolution of species interactions - the geographic mosaic theory of coevolution. Thompson demonstrates how an integrated study of life histories, genetics and the geographic structure of populations yields a broader understanding of coevolution, or the development of reciprocal adaptations and specializations in interdependent species. Using examples of species interaction from a range of taxa, Thompson examines how and when extreme specialization evolves in interdependent species and how geographic differences in specialization, adaptation and the outcomes of interactions shape coevolution. Through the geographic mosaic theory, Thompson creates connections between the study of specialization and coevolution in local communities and the study of broader patterns seen in comparisons of the phylogenies of interacting species.
1,334 citations
148 citations
TL;DR: Gas chromatography shows that two subspecies of the grasshopper Chorthippus parallelus have diverged in the composition of their cuticular hydrocarbons, and the possible consequences of this chemical divergence for mating encounters between the subspecies are discussed.
Abstract: Two subspecies of the grasshopper Chorthippus parallelus (Orthoptera; Acrididae) meet and form a hybrid zone in the Pyrenees. Here we investigate whether the subspecies differ in the blend of cuticular hydrocarbons. Such differences may function as chemical signals, being detected via contact chemoreception and used during mate choice as in other insects. Gas chromatography shows that the subspecies have diverged in the composition of their cuticular hydrocarbons. This difference between subspecies exists over and above variation in cuticular hydrocarbons among individual populations. The majority of the difference can be attributed to the relative amounts of a small group of compounds present in the cuticle. The possible consequences of this chemical divergence for mating encounters between the subspecies are discussed.
50 citations
TL;DR: Data derived from a survey of ostracod valves preserved in 34 Holocene freshwater sediment cores suggest that environmental fluctuations during a period of less than 5000 years were sufficient to provide an advantage to sexually reproducing ostracods over parthenogenetic forms, and suggest that the short-term costs of sexual reproduction are rapidly outweighed by its advantages in a changing environment.
Abstract: Parthenogenetic and sexual reproduction co-occur in many animals. In such groups, determination of the timescale over which parthenogenetic lineages can persist and provide an advantage over sexual reproduction is of considerable importance, as the adoption of either reproductive mode will confer various, but conflicting, adaptational advantages. Data derived from a survey of ostracod valves preserved in 34 Holocene freshwater sediment cores suggest that environmental fluctuations during a period of less than 5000 years were sufficient to provide an advantage to sexually reproducing ostracods over parthenogenetic forms. In addition, asexual species were found not to have colonized water bodies earlier than sexual forms, nor to have persisted for longer. When viewed over timescales such as these, subfossil Ostracoda offer little support for the `general purpose genotype' hypothesis of parthenogenesis, and also suggest that the short-term costs of sexual reproduction are rapidly outweighed by its advantages in a changing environment.
26 citations
TL;DR: Haplotype diversity was as great within species, and in some case within populations, as it was among species and no clear geographical patterns of haplotype distribution were revealed, which suggests that hybridization has occurred during periods of grasshopper range expansion since the last glacial maximum.
Abstract: This work was canied out while Debbie Mason was a research student with Roger Butlin, then a Royal society University Research Fellow in Cardiff. Debbie Mason is now involved in bone disease research and is currently investigating the molecular biology of bone at Bristol University. Roger Butlin is continuing his work on the evolution of mating signals in grasshoppers, and other insects, at The University of L-eeds. Peter Gacesa provided invaluable advice and assistance with molecular techniques for this study. His own research is on alginate metabolism in seaweeds.
18 citations
TL;DR: Diversity in an intensive study of a 1 km transect grasshopper diversity was strongly partitioned between habitat types despite their close proximity, probably enough to have a significant impact on availability of grazing for stock animals.
Abstract: Grasshoppers were collected in the Lake Baringo area of northern Kenya between July 1988 and March 1989. A high overall diversity, 70 species, was observed in an extensive survey. In an intensive study of a 1 km transect grasshopper diversity was strongly partitioned between habitat types (beta-diversity 17.5% of maximum possible) despite their close proximity. Densities reached 0.66 m−2, probably enough to have a significant impact on availability of grazing for stock animals.