Evol Ecol Res 15: 747-756 (2013) Full PDF if your library subscribes.
Cope’s Law of the Unspecialized, Cope’s Rule, and weak directionality in evolution
Pasquale Raia1 and Mikael Fortelius2
1Dipartamento di Scienze della Terra, Ambiente e Risorse, Università di Napoli Federico II, Napoli, Italy and 2Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland and Institute of Biotechnology, University of Helsinki, Helsinki, Finland
Correspondence: P. Raia, Dipartamento di Scienze della Terra, Ambiente e Risorse, Università di Napoli Federico II, 80138 Napoli, Italy.
Background: Edward Drinker Cope nurtured the idea that evolution moves by an inner motor towards the perfection of structures. This concept animated his major contributions to evolutionary theory, including the Law of the Unspecialized and the familiar Cope’s Rule. The former states that clades start with unspecialized forms and evolve towards specialized descendants eventually bound to become extinct because of their ‘overperfection’. Through time, the Law of the Unspecialized has been abandoned, probably because it is dominated by a concept of strong directionality (and the many distortions this concept entails).
Questions: Is directionality in evolution real? If so, does the evidence contradict the Law of the Unspecialized, as is now commonly assumed?
Procedure: We review the Law of the Unspecialized. Then we recast it in modern terms. We highlight the connection between Cope’s Rule and the Law of the Unspecialized.
Conclusions: A form of weak directionality is real. We conclude that the concept of directionality has been unjustly deprecated. It is, in fact, a pervasive, important, and easily testable feature of evolution.
Keywords: Cope’s Rule, Cope’s Law of the Unspecialized, weak directionality, body size, ecological specialization.
DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.
© 2013 Pasquale Raia. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.
Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.
All copies of abstracts and articles must preserve their copyright notice without modification.