Problems due to missing data in phylogenetic analyses including fossils: a critical review

Abstract

We review the widespread notion that the inclusion of taxa scored for relatively few characters is problematic in phylogenetic analyses. Taxa scored for few characters may lead to lack of resolution, but need not. Lack of resolution may be unrelated to missing data when characters conflict. Missing data cannot produce groupings for which there is no evidence. A common approach to avoid the “missing data problem” is to exclude incomplete taxa, but excluding such taxa is inadvisable because the information content of taxa is not necessarily correlated with degree of completeness. Another prevalent strategy—excluding characters with a high proportion of missing data—may actually contribute to the low resolution problem rather than ameliorate it because removing any character data removes potentially informative synapomorphies. Other approaches, including the use of less-than-strict consensus techniques, have the potential to obscure evidence for alternative relationships or, at best, provide incompl...