Monday, November 29, 2010

Why signal selection?

What is signal selection and why is it important?  The short answer is that it describes how organisms communicate reliable information to one another.  I don't think I need to explain why communication is important.  As for the long answer, I would have to refer to several books discussing Amotz Zahavi's Handicap Principle.

In the course of my research the significant influence of Zahavi's ideas in the biological sciences has been impressed upon me.  Many of these books specifically focus on the implications of the Handicap Principle on sexual selection.  Important as that is, it has equally interesting implications for other types of communication between organisms.  Zahavi himself distinguishes between utilitarian selection and signal selection, a redefinition of Darwin's original categories of natural selection and sexual selection.  I have taken Zahavi's term "signal selection" as the name of this blog to honor the importance of this idea.  "Signalling theory" is the term probably more accepted within academic circles when referring to the subject in general. 

Having found already eight books that bear at least passing mention of Zahavi and his work, I am sure to find more references yet.  I have read The God Delusion and The Generous Man already, I am currently finishing The Handicap Principle and would like to read the latest edition of The Selfish Gene next.  In the 1989 edition of this book Dawkins includes a lengthy analysis in favor of the Handicap Principle in the end notes section.  His discussion of the Handicap Principle within the original 1976 body of the book itself is equally enjoyable to read.  He describes one manifestation of it as "a particularly diabolical form of child blackmail" (131), and  "maddeningly contrary" (159), I have also read it described as "paradoxical".  But at the same time the theory makes everything seem so much clearer once it is understood (if a false notion, it is very seductive).  It is the leading theory, in my estimation, to explain truly novel things in the world.  More than ever before, I now know why nature is so beautiful.

Peer review of research is an important tool in the progress of science, and I wondered what Zahavi's peers make of his ideas. One of the great figures in evolutionary biology, W. D. Hamilton, wrote of Zahavi (Narrow Roads of Gene Land, Volume 2: Evolution of Sex, 2002, p210) "I should say that except on the subject of handicaps Zahavi and I have disagreed steadily about many other things, especially kin selection." And on 212: "On the canvas that day Zahavi was mostly the winner and remains so on the most major issue: numerous cases are now known that bear out his insistence on choice for true worth." Other authors have stated that further development of Zahavi's ideas by Grafen "brought animal communication, game theory, and sexual selection together" (Essays in Animal Behaviour, 2005, p44).  Hamilton identified the bright colors of fall foliage as an example of the Handicap Principle in action, see this article by Carl Zimmer.