Since the introduction of mathematical population genetics, its machinery has shaped our fundamental understanding of natural selection. Selection is taken to occur when differential fitnesses produce differential rates of reproductive success, where fitnesses are understood as parameters in a population genetics model. To understand selection is to understand what these parameter values measure and how differences in them lead to frequency changes. I argue that this traditional view is mistaken. The descriptions of natural selection rendered by population genetics models are (...) in general neither predictive nor explanatory and introduce avoidable conceptual confusions. I conclude that a correct understanding of natural selection requires explicitly causal models of reproductive success. *Received May 2006; revised December 2006. †To contact the author, please write to: Department of Philosophy, Kansas State University, 201 Dickens Hall, Manhattan, KS 66506; e‐mail: [email protected] . (shrink)

The lack of water, which has arisen due to reasons such as climate change, excessive and misuse, has become a global problem. The reuse of wastewater is considered as an important solution to overcome this problem. With the technology developed for this purpose, wastewater is treated and used in many fields, especially in irrigation of agricultural products and parks and fire extinguishing. There is no information directly related to the methods of treating polluted water in the religious texts. In the (...) past, when today's technological possibilities were not available, fuqaha determined some treatment techniques, but these are about waters exposed to najāsat (filthy things), not about wastewater that contains a large amount of najis elements. As a matter of fact, it seems impossible to clean wastewater with these methods. With the systems developed today, wastewater can be treated at different levels according to their usage areas. Accordingly, the analysis information regarding the output at each treatment level should be evaluated separately when determining the fiqh provision of treated wastewater. In this study, it is aimed to examine the purification methods discussed in fiqh books together with the relevant texts and to determine the criteria taken as basis in purification and to try to determine the fiqh provision regarding the treated wastewater outputs within these criteria. (shrink)