Un enfoque cladista para la inserción de fósiles en la filogenia

Abstract

The study of fossils is one of the most important fields of biology and geology. However is difficult to insert these forms in phylogenies of modern organisms. This paper proposes a method for inserting fossil forms in cladograms that describe phylogenetic scenarios of recent life forms. Three possible hypothetical scenarios have been considered for the development of this methodology. The method consist in four steps, 1) the phylogenetic reconstruc- tion of the modern forms with the current characters used for the group, 2) the inclusion of the most complete fossil form in the data matrix without the characters coded as “?”, 3) the analytical position of the taxa in the topologies (if there are more than one) using the strict consensus or majority rule consensus, if the first do not resolve any possible group, 4) the inclusion of the fossil form in the position where is most probably inserted with the characters exhibited. A real case has been used to illustrate the validity of this method. The inclusion of fossils with this method shows that the state of preservation of the fossil is not necessarily a good indicator of the importance of the fossil form.