David Magnus

Biologists often define evolution as a change in allele frequencies. Consideration of the evolution of the pocket mouse will show that it is possible to have evolution without any change in the allele frequencies in a population (through change in the genotype frequencies). The implications of this for genic selectionism are then discussed. Sober and Lewontin (1982) have constructed an example to demonstrate the blindness of genic selectionism in certain cases. Sterelny and Kitcher (1988) offer a defense against these arguments which assumes a conventionalist approach to populations. The example considered here will be shown to offer a more plausible and far-reaching argument against the view that alleles can always be seen as the units of selection.

There are many kinds of clinical trials. The regulatory framework within which most drug development takes place appears to be the one that is to be applied to the development of novel stem cell-based clinical trials. In the standard drug development model, appropriate pre-clinical research is conducted, and investigators or research sponsors submit an investigational new drug application to the Food and Drug Administration.If approved, typical clinical trials start with Phase I, which is usually a trial to determine the maximum tolerable dose of a drug. Phase I trials are often referred to as “safety studies” because the primary goal of Phase I research is to determine if an intervention is safe.