Arnon Lotem

From signals to syntax: an evolutionary biologist’s perspective

 

Essay question: What are the main problems in the evolution, and in the evolutionary stability, of structured communication, and how they might be related to your own field of research?

Abstract

The evolutionary pathways from simple biological signals to structured communication involve some of the most complicated and controversial issues in the evolution of social behavior. Scientists who study signaling at the cellular level, or those at the other end of the spectrum, studying language and syntax, are rarely concerned with such evolutionary problems. It is quite often that communication and language are implicitly discussed as a group trait that evolved for efficient communication, while ignoring the pitfall of “group selection” arguments. From an evolutionary perspective, communication (or language) is not a trait of an organism but rather a process, in which organisms send and receive signals. The signal and the response to the signal are therefore the traits under selection, and each should be adaptive based on its own merit. This requires non-trivial cooperation between signalers and receivers, which under most circumstances have conflicts of interests. The theory of costly signaling (based on Zahavi’s Handicap Principle) explains how biological signals evolve to be honest and how communication systems remain stable against cheating. Yet, the evolutionary transition to syntactic or symbolic language is still an open problem. At this stage signals become cheap and easy to fake, and their arbitrary nature increases even further the need for cooperation and coordination between individuals. Some possible hints for understanding the evolution of language may nevertheless be found when studying the mechanism used by animals as signalers and receivers in the realm of costly signaling.

 

 

Background reading:

 

Suggested web site: An introduction to the theory of costly signaling

^{http://calvino.biology.emory.edu/handicap/handicap_intro_1.html}

 

Two of my own relevant papers (PDF files attached):

 

Lotem A. Wagner R.H. & Balshine-Earn S. 1999. The overlooked signaling component in non-signaling behavior. Behavioral Ecology 10: 209-212.

 

Kedar H., Rodriguez-Girones M., Yedvab S., Winkler DW & Lotem A. 2000. Experimental evidence for offspring learning in parent-offsrping communication. Proc. Roy. Soc. Lond. B. 267: 1723-1727

 

 

Further suggested reading

 

Definitions and classification of biological signaling:

 

Maynard Smith J, Harper DGC, 1995. Animal signals: Models and Terminology. J. theor. Biol. 177:305-311.

 

Hasson O, 1997. Towards a general theory of biological signaling. J. theor. Biol. 185:139-156.

 

Evolution of cooperation and the group selection controversy:

 

A basic account of the group selection problem can be found in many textbooks in evolutionary biology, (e.g. Evolution by M. Ridley, chapter 12: The units of selection).

 

Some recent papers:

 

Reev HK 2000. Multi-level selection and Human Cooperation. Evolution and Human Behavior 21:6-72.

 

Nowak, M & Sigmund, K. 1998. Evolution of indirect reciprocity by image scoring. Nature 393:573-577

 

Lotem A., Fishman A. M., & Stone L. 1999. Evolution of cooperation between individuals. Nature 400:226-227

 

The need for honesty in communication within the organism:

 

Zahavi A. 1993. The fallacy of conventional signaling. Phil. Trans. Roy. Soc. B 340:227-230

 

Krakauer, D.C. & Pagel, M. 1996. Selection by somatic signals. Phil.Trans. Roy Soc B 351: 647-658

 

The evolution of language:

 

Nowak M., Plotkin JB. & Jansen VAA. 2000 The evolution of syntactic communication. Nature 404:495-498.

 

Nowak M. & Krakauer DC. 1999. The evolution of language. PNAS 96:8028-8033.