What's wrong with inclusive fitness?

reconstructed for dinosaurs are realistic, because other types of curve might fit better, and few data at their lower ends are currently available. A third crucial question is how birds and their immediate dinosaurian relatives became small. Erickson [1], we think, misstates our results [10,11] when he says: 'It was posited that selection favored reduced body size because it enabled decreases in wing loading and improved power-to-weight ratios.' Our general analysis of growth patterns in dinosaurs showed that adult size and absolute growth rate are usually correlated [12]. As bird ancestors became miniaturized, they retained similar adult body proportions as their larger ancestors. Once bird ancestors became small, regardless of selection pressures, a geometrically similar wing size at this smaller body size would have automatically lowered wing loading, and thus increased aerodynamic lift. Given the scaling of power requirements, we implied that this consideration might be useful in analyzing early flight evolution. We agree on the potential value and use of bone histol-ogy in fossil (and living) vertebrates to understanding the growth strategies of extinct animals. However, the opening chapters of this book are just being written. Acknowledgments We thank Randy Irmis and Drew Lee for reviewing a draft of this article. Expression de la dynamique de croissance dans la structure de l'os périostique chez Anas platyrhynchos. C. R. Long bone histology of the hadrosaurid dinosaur Maiasaura peeblesorum: growth dynamics and physiology based on an ontogenetic series of skeletal elements. Assessing a relationship between bone microstructure and growth rate: a fluorescent labeling study in the King Penguin chick (Aptenodytes patagonicus). Allosaurus: assessing growth strategy and evolution of ontogenetic scaling of limbs. In a recent issue of TREE, Foster et al. [1] defend inclusive fitness theory [2] from recent challenges [3,4]. The main author of these challenges, E.O. Wilson, argues that inclusive fitness (also called kin selection [5]) might not be the main explanation for the evolution of altruism and eusoci-ality. By contrast, Foster et al. claim not only that inclusive fitness is the most prominent explanation for altruism, but also that genetic 'relatedness is always required for altru-ism to evolve' [1]. Here, we take issue with their claim about genetic relatedness and place the debate in a larger historical context. The key finding of inclusive fitness theory is Hamilton's rule [2], which predicts that an altruistic trait will increase in frequency when the inequality rb > c is satisfied. Here, …