Evolution and the levels of selection

Hamilton, and richard dawkins, evolutionary biologists have recognized that natural selection generally does not operate for the good of the group, but rather for the good of lowerlevel units such as the individual, the cell, even the gene. In evolution and the levels of selection samir okasha presents a careful and thorough analysis of the current state of play of attempts to formally analyze questions surrounding the level s at which natural selection can and does operate. A unit of selection is a biological entity within the hierarchy of biological organization that is subject to natural selection. The question of levels of selection on which biologists and philosophers have long disagreed is central to evolutionary theory and to the philosophy of biology. Units and levels of selection stanford encyclopedia of. There is debate over the relative importance of the units themselves. Kin selection theory predicts levels of worker reproduction as a function of the relatedness structure of the workers natal colony and the colony level costs of worker reproduction. Buy evolution and the levels of selection by okasha, samir isbn. There is debate among evolutionary biologists about the extent to which evolution has been shaped by selective pressures acting at these different levels. Selection at the cellular level this process requires just three basic features to operate. Samir okasha, evolution and the levels of selection. Levels of selection in evolution is the first book to provide an overview of the very diverse recent literature on these topics, which ultimately traces back to these pioneering contributions. Okashas book makes the sort of contribution that simply. As an example, imagine a group of cells within one persons liver.

However, these traits are not unique to populations of individuals. For instance, is it group or individual selection that has driven the evolution of altruism. The evolution by selection process may be said to benefit a particular level of entity under selection, through producing adaptations at that level williams 1966, maynard smith 1976, eldredge 1985, vrba 1984. The levelsofselection is one of the most fundamental in evolutionary biology, for it arises directly from the underlying logic of darwinism. Suggested reading pages 197206 in chapter 9 on genomic con. Levels of selection for natural selection to proceed there must be heritable variationin phenotypes and the variation in phenotype must be associated with differential survival andor reproduction, i. By inference then, any entitiesexhibiting heritable variation in rates of reproduction can evolve. Ever since the groundbreaking work of george williams, w. The problem can be seen as the upshot of three factors, each of which was appreciated to some extent by darwin himself. Levels of selection in evolution princeton university press.