OKUSU, A: Embryogenesis and Development of Epimenia babai (Mollusca Aplacophora) Comparative studies of embryology and larval development within and among molluscan groups can inform evolutionary analyses of these groups. Aplacophora are small, shell-less, and vermiform molluscs. Given their hypothesized basal position among molluscs, development of aplacophorans may provide the key to answering major outstanding questions […]

WEBSTER, M.: Allometric patterning in trilobite ontogeny: testing for heterochrony in Nephrolenellus Heterochrony, a decoupling between morphological development and ontogenetic time, has been touted as the commonest mode of evolutionary change. Evolutionary change involving modification to the pattern of morphological development cannot be described as a decoupling between morphological development and time. Conservation of the […]

WOODS, HA*; HOBBIE, SE; MAKINO, W; COTNER, J; HARRISON, JF; ELSER, JJ: Temperature shifts cause systematic changes in biochemical composition of poikilothermic organisms We surveyed the literature to explore the extent to which acclimation temperature influences the nitrogen (N) and phosphorus (P) and of N-rich (protein) and P-rich (RNA) biochemicals in poikilothermic organisms, including bacteria, […]

MCMILLAN, D.M.; TROLL, J.V.; RANK, N.E.; DAHLHOFF, E.P.: Survival, growth and effects of environmental stress in larvae of the Sierra willow beetle Chrysomela aeneicollis The Sierra willow beetle Chrysomela aeneicollis lives in heterogeneous thermal habitats in the Eastern Sierra Nevada. Habitat temperature appears to be a critical factor affecting beetle physiology and genetic variation among […]

RANK, N.E.; DAHLHOFF, E.P.: PGI genotype affects heat shock protein expression and freeze tolerance in the leaf beetle Chrysomela aeneicollis Natural selection may act on enzyme loci through genotypic differences in physiological performance at different temperatures. Allele frequency variation at the phosphoglucose isomerase (PGI) locus in the montane leaf beetle Chrysomela aeneicollis and biochemical differences […]

WILLIAMS, T.D.: Is the egg size-clutch size trade-off based on a resource allocation decision? Life-history trade-offs have proved difficult to demonstrate using phenotypic correlations and there is still surprisingly little empirical evidence for such trade-offs especially at the intraspecific level. In contrast, experimental (hormonal) manipulation of phenotypic traits has provided support for the existence of […]

NEARGARDER, G.G.; DAHLHOFF, E.P.; RANK, N.E.: Effect of PGI genotype and temperature exposure on thermal tolerance of the willow leaf beetle Chrysomela aeneicollis Natural selection may act on loci coding for polymorphic metabolic enzymes when genotypes differ in tolerance to temperature extremes. Allele frequency variation at the glycolytic enzyme locus phosphoglucose isomerase (PGI) relates to […]

GALIS, F.; VANALPHEN, J.J.M.; METZ, J.A.J.: Why five fingers? Evolutionary constraints on digit numbers Evolutionary changes in the number of digits and other limb elements appear to be severely constrained, probably as a result of a low level of modularity during limb development. Reduced limb structures typically develop through a process of construction followed by […]

DAVIS, M.C.: The evolution of paired fin development: Insights from the basal actinopterygian Polyodon The paired appendages of chondrosteans offer a good morphological and phylogenetic intermediate between derived actinopterygian (Danio) and derived sarcopterygian (Mus, Gallus) models. In particular, the paddlefish Polyodon exhibits a broad proximodistal area of overlap between the endochondral and dermal fin skeletons […]

BURIAN, R.M.: Modularity, Development, and Genotype-Phenotype Maps In this paper I examine some surprising consequences of recent results concerning the modularity of the genotype and about the importance of higher-level modules in delimiting body segments. Combining some of these findings with a characterization of genes, at the molecular level, as being nothing but sequences of […]