善待海洋就是善待人类自己

地球实际是一个大水球,其表面积71％为海洋所覆盖,62％的水域深于1000米。陆地生命归因于海洋生命,我们的空气、食物、住所,都是海洋生物圈的一部分。海洋是人类生命支持系统的重要组成部分,人类每年消耗的海洋食物数量比消耗的牛肉和鸡肉数量之和还要多。世界上近80％的动植物生活在海洋里,从2000年开始,世界上平均每个星期发现3种海洋生物新种,每年发现160种新种。在南太平洋喀里东尼亚的巨大珊瑚礁中采集的一块3立方米的样品中,科学家发现了属于3000种的13万个软体动物,其中许多是新种。     

Good genes, old age and life-history trade-offs

The possibility of using old age of a mate as an indicator of genetic quality is currently controversial. Early verbal models as well as a recent simulation study noted that female choice for old mates is beneficial because longevity indicates viability in the current environment. In contrast, a quantitative genetic model of the relationship between age and breeding value of fitness casts strong doubts on the mechanism. The present analysis shows, however, that these doubts are mainly the result of assuming that all variation among individuals arises from differences in allocation between components of fitness. This neglects the possibility of variability in condition as a whole. Instead, when allowing for persistent variability in condition and assuming optimal reaction norms in allocation, it is shown that correlations between survival and genetic quality or fitness can easily be established at all ages. On the other hand, the results also suggest that the validity of verbal arguments is limited, and counterexamples can be generated where low-quality individuals should invest more in survival. Therefore, resolution of the old age indicator problem requires specification of the constraints acting on life-history characteristics.     

Good chemistry

The subject matter in chemistry courses reflects almost nothing of the issues that chemists are interested in. It is important to formulate a set of topics--and a Medical College Admissions Test reflecting them--that would leave chemistry departments no choice but to change their teaching.