A total of 944 expressed sequence tags generated 2212 EST loci mapped to homoeologous group 1 chromosomes in hexaploid wheat. EST deletion maps and the consensus map of group 1 chromosomes were constructed to show EST distribution. EST loci were unevenly distributed among chromosomes 1A, 1B, and ID with 660, 826, and 726, respectively. The number of EST loci was greater on the long arms than on the short arms for all three chromosomes. The distribution of ESTs along chromosome arms (...) was nonrandom with EST clusters occurring in the distal regions of short arms and middle regions of long arms. Duplications of group 1 ESTs in other homoeologous groups occurred at a rate of 35.5%. Seventy-five percent of wheat chromosome 1 ESTs had significant matches with rice sequences, where large regions of conservation occurred between wheat consensus chromosome 1 and rice chromosome 5 and between the proximal portion of the long arm of wheat consensus chromosome 1 and rice chromosome 10. Only 9.5% of group 1 ESTs showed significant matches to Arabidopsis genome sequences. The results presented are useful for gene mapping and evolutionary and comparative genomics of grasses. (shrink)

The fundamental tenet of contemporary sociobiology, namely the assumption of a single process of evolution involving the selection of genes, is critically examined. An alternative multiple-level, multiple-process model of evolution is presented which posits that the primary process that operates via selection upon the genes cannot account for certain kinds of biological phenomena, especially complex, learned, social behaviours. The primary process has evolved subsidiary evolutionary levels and processes that act to bridge the gap between genes and these complex behaviours. The (...) subsidiary levels are development, individual animal learning, and socioculture itself. It is argued that individual learning is pivotal to the derivation and biological analysis of culture. The differences between cultural and noncultural societies are stressed. It is concluded that such a multiple-level model of evolution can form the basis for reconciling opposing sides in the sociobiology debate. (shrink)

Many of the commentaries cohere around two major points of criticism. The first is that we have omitted discussion of the mechanisms that are assumed to operate at levels 2, 3, and 4.Campbell, Cloak, Dewsbury, Eckberg, Mundinger, Pulliam, Richerson & Boyd, Slobodkin, Simon, Williams, andWahlstenall make comments that bear on this point. The second point is that we have omitted discussion of the fact that "organisms change the environment by their activities" and thereby modify the selection pressures that act on (...) them. Apart from Lewontin, this point has been raised in different forms byBarkow, Chase, Hull, Perzigian, Ruyle, and less directly bySlobodkin. Stemming from these two basic omissions there is a third general criticism. Numerous commentators have pointed out that we have failed to discuss sufficiently either the extent or nature of the constraints that may or may not be operating on supraordinate evolutionary processes as a function of their nested relationships to subordinate evolutionary processes within our scheme. We start by acknowledging these three basic omissions. We agree that they exist and that they are serious. (shrink)

We distinguish three different readings of the intuitionistic notions of validity, soundness, and completeness with respect to the quantification occurring in the notion of validity, and we establish certain relations between the different readings. For each of the meta-logicalnotions considered we suggest that the "most natural" reading (which is not the same for all cases) is precisely the one which is required by the recent intuitionistic completeness theorems for IPC.

In meeting the challenges of fashioning a new health care system, South Africa stands poised to contribute to a better future for its own citizens and the subcontinent.

This volume of the Amsterdam edition of the Latin texts of Erasmus contains several works intended for scholarship in Classics. It includes discourse on the correct pronunciation of Latin and Greek, rhetoric, and Classical Latin, in a compendium of the handbook by Lorenzo Valla, as well as a declamation in praise of medicine.