Do early branching lineages signify ancestral traits?

• Published in: Trends in ecology & evolution (Amsterdam) 2005-03, Vol.20 (3), p.122-128
• Main Authors: Crisp, Michael D., Cook, Lyn G.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biological evolution; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution
• ISSN: 0169-5347; 1872-8383
• DOI: 10.1016/j.tree.2004.11.010

A reverence for ancestors that has pre-occupied humans since time immemorial persists to the present. Reconstructing ancestry is the focus of many biological studies but failure to distinguish between present-day descendants and long-dead ancestors has led to incorrect interpretation of phylogenetic trees. This has resulted in erroneous reconstruction of traits such as morphology and ancestral areas. Misinterpretation becomes evident when authors use the terms ‘basal’ or ‘early diverging’ to refer to extant taxa. Here, we discuss the correct interpretation of trees and methods for reconstructing the ancestral features of organisms using recently developed statistical models. These models can be inaccurate unless they use information that is independent of phylogenies, such as genetics, molecular and developmental biology, functional morphology, geological and climatic processes, and the fossil record.