My thoughts on Ancestor-Descendant Relationships

Following the doctrine of cladistics, the mere thought of investigating ancestor and descendant relationships was branded as a sinful act. Such orthodoxy in science needs to be over turned and a new generation of scientists are attempting the forbidden act. Benoit Dayrat, a scientist who has published on botany and fossil snails wrote a brilliant, if someone historical, call to arms for paleontologists to launch investigations into ancestor-descendant relationships. "Ancestor-descendant relationships [sic] should be studied as often as possible because they are more accurate representations of the evolutionary history than sister-group relationships." p. 351, and later "Ancestor-descendant relationships should be investigated as often as they can be." p. 352. (Dayrat, 2005).



However, before such investigations can be launched there is the slight problem of how one goes about searching and proving ancestor-descendant relationships. There are basically three schools of thought. ONE, use stratigraphy to accept or reject various most parsimonious trees or TWO, include the stratigraphic relationships within the data somehow, or THREE use a phenetic approach of comparing morphology through time. While not offering a solution to which is method is most appropriate, Dayrat concludes that the best way of depicting the evolutionary history is by a "tree of life" and hierarchical classifications fail miserably at conveying useful information.




Dayrat, Benoit (2005) Ancestor-descendant relationships and the reconstruction of the Tree of Life Paleobiology 2005 31: 347-353.