Evolutionary changes in the complexity of the tectum of nontetrapods: a cladistic approach.

ABSTRACT:

Background

The tectum is a structure localized in the roof of the midbrain in vertebrates, and is taken to be highly conserved in evolution. The present article assessed three hypotheses concerning the evolution of lamination and citoarchitecture of the tectum of nontetrapod animals: 1) There is a significant degree of phylogenetic inertia in both traits studied (number of cellular layers and number of cell classes in tectum); 2) Both traits are positively correlated accross evolution after correction for phylogeny; and 3) Different developmental pathways should generate different patterns of lamination and cytoarchitecture.

Methodology/principal findings

The hypotheses were tested using analytical-computational tools for phylogenetic hypothesis testing. Both traits presente

SUBMITTER: Maximino C 

PROVIDER: S-EPMC2571994 | biostudies-literature | 2008

REPOSITORIES: biostudies-literature