EVOLUTION OF PHENOTYPE–ENVIRONMENT ASSOCIATIONS BY GENETIC RESPONSES TO SELECTION AND PHENOTYPIC PLASTICITY IN A TEMPORALLY AUTOCORRELATED ENVIRONMENT

Covariation between population‐mean phenotypes and environmental variables, sometimes termed a “phenotype–environment association” (PEA), can result from phenotypic plasticity, genetic responses to natural selection, or both. PEAs can potentially provide information on the evolutionary dynamics of a particular set of populations, but this requires a full theoretical characterization of PEAs and their evolution. Here, we derive formulas for the expected PEA in a temporally fluctuating environment for a quantitative trait with a linear reaction norm. We compare several biologically relevant scenarios, including constant versus evolving plasticity, and the situation in which an environment affects both development and selection but at different time periods. We find that PEAs are determined not only by biological factors (e.g., magnitude of plasticity, genetic variation), but also environmental factors, such as the association between the environments of development and of selection, and in some cases the level of temporal autocorrelation. We also describe how a PEA can be used to estimate the relationship between an optimum phenotype and an environmental variable (i.e., the environmental sensitivity of selection), an important parameter for determining the extinction risk of populations experiencing environmental change. We illustrate this ability using published data on the predator‐induced morphological responses of tadpoles to predation risk.     

Development of eggs of Antarctic krillEuphausia superba in relation to pressure

Summary This paper focuses upon the influence of increasing hydrostatic pressure on the development of krill eggs at 2°C. This experimental study on the embryology ofEuphausia superba was conducted at the Palmer Station, Antarctica during the 1982–1983 austral summer. The gravid females were captured from Bransfield Strait aboard theR/V Hero. The various embryological stages such as early cleavage, blastula, gastrula and limb-bud nauplius larva were defined and described. The duration for these various developmental stages at 1 atm was also established at +2°C and compared with the timing of this event at negative temperature. Krill embryonic development is inhibited at 4°C. The sinking rate of eggs and embryos was also measured at various pressure. The data suggest that pressure does not significantly influence the sinking rate. There appears to be a wide variation of sinking rates of eggs within the same brood. based on a simulated model of sinking rate, egg development was studied at increasing pressure. Pressure of 5–20 atm accelerates the rate of cleavage and therefore the 32-celled stage is attained within 5–8 h, while at 1 atm it took 13 h to reach the same stage. Pressure thus seems to have some influence on the duration of the development of different developmental stages of krill embryos.     

东洋区五种并脊天牛的国家级新记录（鞘翅目：天牛科：沟胫天牛亚科：楔天牛族）

报道东洋区五种并脊天牛的一些国家级新记录。常卿并脊天牛Glenea changchini Lin&Lin,2011是越南新记录种;郎氏并脊天牛G.rondoni Breuning,1963是泰国新记录种;窄条并脊天牛G. subregularis Pic,1943是老挝新记录种;拟绿缝并脊天牛G. subviridescens Breuning,1963是中国、越南和泰国新记录种;绿缝并脊天牛G. viridescens Pic,1927是中国和老挝新记录种。提供了相关种类的模式标本照片和新记录证据标本照片。