Social semantics: how useful has group selection been?

In our social semantics review (J. Evol. Biol., 2007, 415–432), we discussed some of the misconceptions and sources of confusion associated with group selection. Wilson (2007, this issue) claims that we made three errors regarding group selection. Here, we aim to expand upon the relevant points from our review in order to refute this claim. The last 45 years of research provide clear evidence of the relative use of the kin and group selection approaches. Kin selection methodologies are more tractable, allowing the construction of models that can be applied more easily to specific biological examples, including those chosen by Wilson to illustrate the utility of the group selection approach. In contrast, the group selection approach is not only less useful, but also appears to frequently have negative consequences by fostering confusion that leads to wasted effort. More generally, kin selection theory allows the construction of a unified conceptual overview that can be applied across all taxa, whereas there is no formal theory of group selection.     

Thymidine Phosphorylation in Arachis hypogaea by Combined Activities of Adenosine Triphosphate Phosphohydrolase and Nucleoside Phosphotransferase

Extracts from hypocotyls of germinating peanuts (Arachis hypogaea L.) stimulated the formation of thymidine monophosphate from thymidine and adenosine triphosphate in the presence of magnesium ions. Such extracts were incapable of incorporating isotopic phosphorus from gamma-labelled adenosine triphosphate into thymidine during the synthesis of thymidine monophosphate but were competent in transferring phosphorus from alpha-labelled adenosine triphosphate to thymidine. The apparent thymidine kinase activity thus appeared to result from the combined activities of an adenosine triphosphatase (adenosine triphosphate pyrophosphohydrolase, E. C. 3.6.1.3) and a nucleoside phosphotransferase (E. C. 2.7.1.77). The latter two enzymes could be largely separated by using DEAE-Sephadex chromatography.     

When rare species become endangered: cryptic speciation in myrmecophilous hoverflies

The myrmecophilous hoverfly, Microdon mutabilis, is listed as a ‘Rare’ or ‘Nationally Notable Species’ in UK Red Data Books. As an obligate social parasite, feeding only from ant colonies, its life‐style satisfies theoretical conditions under which cryptic speciation is predicted to evolve; namely, strong selection for nonmorphological adaptations that enhance its exploitation of a local subspecies or populations of its host. Samples of larvae and pupae in Ireland, Scotland and England showed that M. mutabilis exploits a single and different host ant species on different sites across its range. In nine southern English colonies, 95.6% of infested nests were of Myrmica scabrinodis whereas in six Irish and two Scottish colonies 100% and 94.2%, respectively, of the infested nests were of Formica lemani, despite M. scabrinodis being common at all sites. Although the adults from ‘scabrinodis’ (and lemani) populations are cryptic, morphometric measurements of pupae showed consistent diagnostic characters that were sufficiently distinct for these ecotypes to be classed as separate species. We conclude that M. mutabilis is the ‘lemani‐type’ and designate the ‘scabrinodis‐type’ as a new species, Microdon myrmicae spec. nov. Thus, one of the listed threatened species of the British Isles becomes two species, each possessing about half the number of populations and occupying half the range of the original ‘species’. Each also inhabits a different serai stage within grassland or heathland, and will require a different management regime if its declining populations are to be conserved. ‘M. mutabilis’ is reported with other host ant species on the European continent. In the light of our results, these may prove to be additional cryptic species. We suggest that cryptic speciation is apt to evolve in species, such as myrmecophiles, endoparasites and koinobiont parasitoids, whose life‐styles result in strong selection on their physiological or behavioural characters. The implications for Red Data Book classifications and for practical conservation are discussed. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 75 , 291–300.     

Interspecific Pollen-Pistil Interaction in Eucalyptus L'Her. (Myrtaceae): The Effect of Taxonomic Distance

The pollen-pistil interaction was investigated in three intraspecific,57 interspecific and six intergeneric crosses using three speciesof Eucalyptus (Myrtaceae) subgenus Symphyomyrtus, section Bisectariaas female parents Interspecific prefertilization isolation occursin the pistil and manifests as a number of pollen-tube abnormalitiesin the style and ovary associated with a lowered probabilityof ovule penetration The major selection points in the pistilare the upper style and the ovary The seventy of abnormalitiesand the probability of pollen-tube arrest in the pistil wasproportional to the taxonomic distance between parent speciesOvule penetrations were seen mainly in crosses within the sectionBisectaria or between the sections Bisectaria and Adnataria Pollen storage, style length and mean maximum temperature duringthe flowering period of the male parent had no significant effecton pollen-tube growth in the crosses used Mechanisms of reproductiveisolation are discussed in relation to evolutionary relationshipsand the implications for taxonomic groupings Eucalyptus L'Hér, pollen-pistil interaction, incongruity, interspecific hybridization, pollen-tube growth, breeding system, taxonomy     

Diel organization of behaviour in milkweed bugs, Oncopeltus spp.

ABSTRACT. Daily cyclic activities in various behaviours were similar in three species of tropical Oncopeltus (Heteroptera, Lygaeidae). Opposition in females and general movement in both sexes peaked in the middle to late light period. In contrast, feeding and mating peaked at the end of the light period and the beginning of the dark respectively. Other behaviours also tended to display one or the other of these patterns. The diel timing of behaviour observed in this study essentially duplicated the periodicities of a migratory population of Oncopeltus fasciatus from Iowa. The similarity of results across species and populations suggests a general pattern for the genus which probably serves to synchronize behaviours with environmental cycles and appropriate physiology. This similarity is interesting in view of the broad geographical range of the genus across both temperate zone and tropics and in view of the differences among populations with respect to photoperiodic determination of diapause.     

A Proteus inconstans which Produces 'Cabbage Odour' in the Spoilage of Vacuum-packed Sliced Bacon

The isolation and identification of a species of Proteus inconstans capable of producing 'cabbage odour' spoilage of sliced vacuum-packed bacon are described. Gas chromatographic-mass spectrometric analysis indicated that the odoriferous compound was methane thiol. Data are presented on the effect of the pH and salt level on the growth of the organism in laboratory media and the production of methane thiol in bacon.