A report on "One Day Symposium on Numerical Cladistics"

A recent symposium on numerical cladistics held at the American Museum of N atural History in New York City, addressed novel methods for searching tree space, applications of randomizations in cladistic analysis, and data mana gement. One of the major concerns in systematics is that of finding the glo bal optimum in tree length. The space to search is complex because it inclu des many local optima. It is a difficult task to escape local optima withou t a great loss in efficiency. The ideal is to search among suboptimal topol ogies and still obtain an answer in a reasonable amount of time. Nixon pres ented a new family of methods called "parsimony ratchet," which are success ful at escaping local optima. Moilanen presented a new program which may ha ve similar advantages. Two presentations, one by Goloboff and Farris and an other by Farris, Goloboff, Kallersjo, and Oxelman, introduced modifications to parsimony jackknifing that improved its accuracy when compared to norma l heuristic searches. Wheeler discussed the advantages of new methods of an alyzing DNA and protein sequence data, which eliminate multiple alignment; the most recent one packs nucleotides into strings which constitute the new characters. Siddall discussed different applications of randomization in c ladistics and their logical consistency, finding some more acceptable than others. Nixon and Carpenter presented a new program for managing data. This symposium will probably be a landmark judging from the originality and pra cticality of the points presented. (C) 1999 The Willi Hennig Society.