The concept of a tness landscape arose in theoretical biology, while that of eectiv e tness has its origin in evolutionary computation. Both have emerged as useful conceptual tools with which to understand the dynamics of evolutionary processes, especially in the presence of complex genotype-phenotype relations. In this contribution we attempt to provide a unied discussion of these two approaches, discussing both their advantages and disadvantages in the context of some simple models. We also discuss how tness and eectiv e tness change under various trans- formations of the conguration space of the underlying genetic model, concentrating on coarse graining transformations and on a particular coordinate transformation that provides an appropriate basis for illuminating the structure and consequences of recombination.