TESTING MACROEVOLUTIONARY HYPOTHESES WITH CLADISTIC ANALYSIS: EVIDENCE AGAINST RECTANGULAR EVOLUTION

摘要: The properties of cladistic data sets from small monophyletic groups (6-12 species) are investigated using computer simulations macroevolution. Two evolutionary models simulated: gradualism and the punctuated-equilibrium hypothesis. Under conditions our these two evolution make consistently different predictions about distribution autapomorphies among species. When strict stasis is enforced, hypothesis predicts that most expected number per species will be zero, no matter how many characters used in analysis. As analysis increases, becomes bimodal. gradualism, remains unimodal under all conditions, but without can fall to zero. A survey real cladograms extant a wide range taxa indicates do not hold. This constitutes strong evidence against