Introduction: Darwinian selection, selective breeding and the welfare of animals

Abstract

The 150th anniversary of the publication of The Origin of Species… is a good time to consider how selection can affect welfare — the quality of life. Darwin (1859) quoted Youatt's description of selective breeding: “…the magician's wand, by means of which he may summon into life whatever form and mould he pleases”. Evolution has fairly recently included us humans in its toolbox, alongside its older instruments, such as climate and disease, as significant agents of selection. We have taken to this work vigorously and have summoned into life an extraordinary array of creatures. It is only much more recently, with the development of interest in animal welfare science, that the welfare consequences of this have begun to be critically reviewed. There are two ways that selection can affect welfare: (i) by resulting in changes that make aversive feelings more likely, eg by predisposing to disease or by altering behaviour such as to increase risk of disease or injury, and (ii) by altering sensitivity of the affect systems such that animals feel, for example, more (or less) pain or fear in response to a stimulus than their ancestors would have. Comparing natural and human selection — that is, the simultaneous scrutiny of all aspects of biology as opposed to our selection for one or two features that appeal to us — Darwin (1859) wrote: “Can we wonder, then, that nature's productions should be far ‘truer’ in character than man's productions; that they should be infinitely better adapted to the most complex conditions of life, and should plainly bear the stamp of far higher workmanship”. The aims of this meeting were to discuss how selection can affect welfare and how we can improve our workmanship in the interests of animal welfare.