Acknowledgments

Some of the work mentioned here was carried out while I was a visiting researcher with the Swarm Project Group at the Santa Fe Institute. This visit was made possible by generous support from Dublin City University and the Swarm Project. Swarm has been supported by Grant No. N00014-94-1-G014 from the Department of the Navy, Naval Research Laboratory, acting in cooperation with the Advanced Research Projects Agency. Swarm has also benefited from earlier support from The Carol O'Donnell Foundation and from Mr. and Mrs. Michael Grantham.

The report was prepared at the kind invitation of Gertrudis Van de Vijver, of the Research Community on Evolution and Complexity, Fund for Scientific Research, Flanders.

All errors remain, of course, my own responsibility.

mcmullin@eeng.dcu.ie