Unto Others, Sober and Wilson 1998

This book is the modern argument for group selection, and is difficult not to read as an answer to The Selfish Gene, though, as elaborated in the book, the selfish gene is jus one of the ideas in evo bio that has given group selection a hard time. The first half seems to be Wilson, focusing on biology, and the second half was probably written by Sober, focusing on altruism in human psychology, with a heavy emphasis on the philosophical angles. You can tell becase the length of chapters and style of writing changes from parts one and two. Also, the work pluralism starts popping in in the second half and in the conclusion. I only skimmed the second half, focusing on the first. Surprisingly, it seems that most of the group selection argument involves the systemetization of Simpson's paradox. On the whole, Wilson seems pretty reasonable, and is eager to acknowledge the limits of group selection-based explanation.

Good bits

• For Dawkins, the focus is on genes because genes, are the replicators, not the individuals or groups. The ability to replicate is what makes memes suitable for the application of evolution, where groups aren't. The core of Wilson's response to this is on page 97.

"Dawkins (1976, 1982, 1989) statees that individuals are exceptionally good vehicales of selection because the opportunities for within-individual selection are so limited. With only a few exceptions, the only way for a gene to increase its fitness is to increase he fitness of the entire genome. The implication has been drawn that most groups ar not good vehicales of selection because they do not limit within-group selection to this degree (Sterelny 1996)"

• Wilson's steps to follow in determining level of group selection:

1. 1. Determine what would evolve in group selection were the only evolutionary force.
   2. Determine what would evolve in individual selection were the only evolutionary force.
   3. Examine the basic ingredients of natural selection at each level

Determine the pattern of phenotypic varition within and among groups

"A population structure in wich all the members of each group qre identical and groups differ from each other is maximally conduciv to group selection. Similarly, natural selection occurs only at the individual level when members of a group differ from each other but each group has exactly the same composition of members. Between these two extremes..."p.105

Determine the heritability of phenotypic differences

Determine the fitness consequences of phenotypic variation

• "We therefore note the following assymetry: Within-group selection can favor any behavior, depending on the social norm of the group. Between-group selection favors only social norms that lead to functionally adaptive groups."p.152

Question

• How does mutual dependance for survival evolve? And what is its relationship in evolution to defection?