On the Unity and Diversity of Cultures

Attempts to display the underlying similarities of superficially different cultures in terms of basic needs, problems, drives, etc., fail, not, as is usually argued, because of paucity of basic materials relative to superstructure, but rather because of a logical feature of the concepts of need, problem, etc. Societies certainly have needs and problems, which they satisfy and solve, but these already presuppose the existence of a society that constantly subjects its environmental and biological endowment to re-evaluation. The needs of a society are not "given," therefore, but are functions of an already developed culture, and for this reason they cannot be thought of as constants variably filled with diverse cultural content. [methodology, cultural relativism, needs (basic), meta-anthropology, semantics]     

Food niches of sympatric Marsh Harriers Circus aeruginosas and Hen Harriers C. cyaneus on the Dutch coast in winter

Analysis of pellets collected from adjacent communal winter roosts of Marsh Harriers Circus aeruginosus and Hen Harriers C. cyaneus on an extensive saltmarsh in the southwest Netherlands showed highly significant differences between the diets of the two species. Marsh Harrier diet showed no change throughout January, February and March. They specialized on ducks, which were about half of their prey numerically and more important by weight. Although Marsh Harriers sampled other prey, this remained at a low level and showed no seasonal response to the availability of young lagomorphs. Hen Harriers occupied the niche of a generalist predator, having a broader diet and responding to the presumed changes in availability of prey with diet shifts. In November, about half of their prey items were passerines but these declined in importance in December, and small mammals rose. The proportions of both small mammals and birds fell in February and March, due to increasing dependence on young lagomorphs. Diet overlap between the two species was greatest in January and declined in February and March.     

Piecing together an integrative taxonomic puzzle: microsatellite,wing shape and aedeagus length analyses of Bactrocera dorsalis s.l. (Diptera: Tephritidae) find no evidence of multiple lineages in a proposed contact zone along the Thai/Malay Peninsula

Bactrocera dorsalis (Hendel) and B. papayae Drew & Hancock represent a closely related sibling species pair for which the biological species limits are unclear; i.e. it is uncertain if they are truely two biological species, or one biological species which has been incorrectly split taxonomically. The geographical ranges of the two taxa are thought to abut or overlap on or around the Isthmus of Kra, a recognised biogeographic barrier located on the narrowest portion of the Thai Peninsula. We collected fresh material of B. dorsalis s.l. (i.e. B. dorsalis s.s.+ B. papayae) in a north–south transect down the Thai Peninsula, from areas regarded as being exclusively B. dorsalis s.s., across the Kra Isthmus, and into regions regarded as exclusively B. papayae. We carried out microsatellite analyses and took measurements of male genitalia and wing shape, both used previously to separate the taxa. No significant population structuring was found in the microsatellite analysis, consistent with one, predominantly panmictic population. Both morphological datasets showed consistent, clinal variation along the transect, without disjunction. No evidence supported historical vicariance driven by the Isthmus of Kra, and no dataset supported the current taxonomy of two species. Rather, within and across the area of range overlap or abutment between the two species, only continuous morphological and genetic variation was recorded. Recognition that morphological traits previously used to separate these taxa are continuous, and that there is no genetic evidence for population segregation in the region of suspected species overlap, is consistent with a growing body of literature that reports no evidence of biological differentiation between these taxa.     

Metamorphosis from the Phoront to the Trophont in Hyalophysa*

SYNOPSIS. The nature and sequence of changes involved in the metamorphosis of the phoront of Hyalophysa have been examined in the light microscope using both living and silver-impregnated ciliates. The phoront's infraciliature, which resembles that of the migratory tomite, differentiates to the trophont (feeding stage) infraciliature without an intervening dedifferentiation. The primary visible event of metamorphosis is the growth of the metastomial area that distorts the meridional somatic kineties so that they curve or spiral around it. The distinct borders and intense argentophilia of the metastomial area suggest that it is a discrete organelle which is probably involved in the management and concentration of a large volume of dilute food. The anterior ventral field of kinetosomes, whose presence distinguishes Hyalophysa from Gymnodinioides, forms from a disorganized anterior segment of falciform field 9. The rapid and pronounced elongation of the somatic kineties supports our view that the kinetodesmos elongates by the sliding of its component subfibrils upon one another, and that the accessory kinetosomes seen in the electron microscope become functional at metamorphosis. The movement of the kineties and contractile vacuole pore during metamorphosis suggests that differentiation in this instance is not directed by pellicular “fields” but by morphogenetic movements of the underlying cytoplasm.