Does natural selection act primarily on individual organisms, on groups, on genes, or on whole species? Samir Okasha provides a comprehensive analysis of the debate in evolutionary biology over the levels of selection, focusing on conceptual, philosophical and foundational questions. A systematic framework is developed for thinking about natural selection acting at multiple levels of the biological hierarchy; the framework is then used to help resolve outstanding issues. Considerable attention is paid to the concept of causality as it relates to the levels of selection, in particular the idea that natural selection at one hierarchical level can have effects that 'filter' up or down to other levels.
Unlike previous work in this area by philosophers of science, full account is taken of the recent biological literature on 'major evolutionary transitions' and the recent resurgence of interest in multi-level selection theory among biologists. Other biological topics discussed include Price's equation, kin and group selection, the gene's eye view, evolutionary game theory, outlaws and selfish genetic elements, species and clade selection, and the evolution of individuality. Philosophical topics discussed include reductionism and holism, causation and correlation, the nature of hierarchical organization, and realism and pluralism.
1. Natural Selection in the Abstract
2. Selection at Multiple Levels: Concepts and Methods
3. Causality and Multi-level Selection
4. Philosophical Issues in the Levels of Selection Debate
5. The Gene's Eye View and its Discontents
6. The Group Selection Controversy
7. Species Selection, Clade Selection and Macroevolution
8. Levels of Selection and the Major Evolutionary Transitions
– Winner of the Lakatos Award 2009 for outstanding contribution to the philosophy of science
"A clearly written, unique and useful book"
– Elizabeth Lloyd, Trends in Ecology and Evolution
"A major conceptual contribution to evolutionary theory [...] Okasha's book makes the sort of contribution that will not be able to be ignored by anyone interested in this field for many years to come."
– Massimo Pigliucci, Biology and Philosophy
"Evolution and the Levels of Selection is a major contribution toward putting this controversial area on a coherent conceptual and philosophical footing [...] Okasha has greatly clarified many of the central issues. I can't imagine anyone working on multilevel selection – or attempting to dismiss it – without reading this book."
– David Jablonski, Science
"Sam Okasha's wonderful new book [...] is a philosophical examination of the conceptual framework that multi-level selection theory deploys [...] It is gratifying that his book engages the details of mathematical models and at the same time connects those details with broader philosophical questions."
– Elliott Sober, Bioscience
" [...] an extremely thought-provoking and important book about a dificult and highly technical topic [...] This is not a book to pull a chapter out of, but instead demands a careful reading of the whole text. Those who do will be rightly rewarded."
– Matt Haber, MIND