This paper responds to the essay reviews by David Haig, Alan Love and Rachel Brown of my recently published book “Homology, Genes and Evolutionary Innovation”. The issues addressed here relate to: the notion of classes and individuals, issues of explanatory value of adaptive and structuralist explanations in evolutionary biology, the role of homology in evolutionary theory, the limits of a pluralist stance vis a vis alternative explanations of homology, as well as the question whether and to what extend the perspective (...) laid out in HGEI can be or should be transferred to other branches of study, like comparative behavioral biology. (shrink)

I argue that an explicit distinction between cognitive characters and cognitive phenotypes is needed for empirical progress in the cognitive sciences and their integration with evolution-guided sciences. I elaborate what ontological commitment to characters involves and how such a commitment would clarify ongoing debates about the relations between human and nonhuman cognition and the extent of cognitive abilities across biological species. I use theoretical proposals in episodic memory, language, and sociocultural bases of cognition to illustrate how cognitive characters are being (...) introduced in scientific practice. (shrink)

Advances in developmental genetics and evo-devo in the last several decades have enabled the growth of novel developmental approaches to the classic theme of homology. These approaches depart from the more standard phylogenetic view by contending that homology between morphological characters depends on developmental-genetic individuation and explanation. This article provides a systematic re-examination of the relationship between developmental and phylogenetic homology in light of current evidence from developmental and evolutionary genetics and genomics. I present a qualitative model of the processes (...) that cause de-coupling of morphological and molecular evolution by developmental system drift (DSD), and hypothesize that DSD is a widespread and regular stochastic process that is predictable from parameters such as population size, pleiotropy, and regulatory redundancy. These theoretical findings support an integrative approach in which models of DSD aid in determining when developmental-genetic explanations of homology apply and when other explanations such as stabilizing selection are needed. I argue that a phylogenetic monism about the definition and criteria of homology supports the integration of different explanations into a theory of homology better than pluralism does. (shrink)