Grafen Alan, Archetti Marco
Zoology Department, Oxford OX1 3PS, UK.
J Theor Biol. 2008 Jun 21;252(4):694-710. doi: 10.1016/j.jtbi.2008.01.021. Epub 2008 Jan 31.
Biological explanations are given of three main uninterpreted theoretical results on the selection of altruism in inelastic viscous homogeneous populations, namely that non-overlapping generations hinder the evolution of altruism, fecundity effects are more conducive to altruism than survival effects, and one demographic regime (so-called death-birth) permits altruism whereas another (so-called birth-death) does not. The central idea is 'circles of compensation', which measure how far the effects of density dependence extend from a focal individual. Relatednesses can then be calculated that compensate for density dependence. There is very generally a 'balancing circle of compensation', at which the viscosity of the population slows up selection of altruism, but does not affect its direction, and this holds for altruism towards any individual, not just immediate neighbours. These explanations are possible because of recent advances in the theory of inclusive fitness on graphs. The assumption of node bitransitivity in that recent theory is relaxed to node transitivity and symmetry of the dispersal matrix, and new formulae show how to calculate relatedness from dispersal and vice versa.
针对非弹性粘性均匀种群中利他主义选择的三个主要未解释的理论结果给出了生物学解释，即不重叠世代阻碍利他主义的进化，繁殖力效应比利生效应更有利于利他主义，以及一种人口统计模式（所谓的死亡-出生）允许利他主义而另一种（所谓的出生-死亡）则不允许。核心思想是“补偿圈”，它衡量密度依赖效应从一个焦点个体延伸的程度。然后可以计算出补偿密度依赖的亲缘关系。一般来说，存在一个“平衡补偿圈”，在这个补偿圈中，种群的粘性减缓了利他主义的选择，但不影响其方向，这适用于对任何个体的利他主义，而不仅仅是紧邻个体。由于近期关于图上广义适合度理论的进展，这些解释成为可能。该近期理论中节点双传递性的假设被放宽为节点传递性和扩散矩阵的对称性，新公式展示了如何从扩散计算亲缘关系，反之亦然。
