Animal Behavior - Biology 4200/5430 |
Bowling Green State University, Fall 2009 |
<Altruism> and reciprocity, Self-sacrificing Behavior: e.g. vampire bats, guard bees, Cooperative breeding, e.g. African Kingfishers, Acorn Woodpeckers, Florida Scrub Jay;
The general expectation is that the evolution of altruistic traits is not compatible with selfish gene theory. How could such a mechanism reinforce a behavior jeopardizing ones own interests at the expense of another's? Altruistic behavior could be rooted through group selectionist thinking where altruistic traits favor reproductive success of a group at the expense of that of an individual. However, an individual fitness solution to the paradox goes as follows: genes are favored that produce a disproportionate propagation of ones genes to subsequent generations even if it is at the expense of the individual. This may occurr directly through either reproducing personally or indirectly by encouraging the reproduction of close relatives who share many of ones genes. Under those circumstances altruistic behaviors should primarily be directed towards close relatives who share many of the genes as compared to non-relatives who share fewer of them.
An individual behaves in such a way as to enhance the reproduction of another individual, at a cost to its own fitness. (e.g., Sterile workers in social insects who give up all reproduction for the benefit of their mother queen. Mutual or delayed benefits can’t account for this one: sterile workers never get to produce any daughters.)
"It rapidly became clear to me that the most imaginative way of looking at evolution, and the most inspiring way of teaching it, was to say that it's all about the genes. It's the genes that, for their own good, are manipulating the bodies they ride about in. The individual organism is a survival machine for its genes" -- Richard Dawkins