Monday, March 16, 2009

Comptes Rendus Palevol Special Issue


(not current issue)
The current issue of Comptes Rendus Palevol, Volume 8, Issues 2-3, (March-April 2009) is a special issue with articles devoted to the Evolutionary History of Life.

A few of the articles include:
Les premiers vertébrés et les premières étapes de l’évolution du crane by Philippe Janvier

Saurischian origins and evolution by Ronan Allain and Emilie Lang

The origin and evolution of birds: 35 years of progress . by Kevin Padian and Armand de Ricqles

Abstract:
Birds are dinosaurs – specifically, small feathered and flighted theropod dinosaurs that probably originated in Laurasia during the Late Jurassic over 140 million years ago. They are most closely related to other small theropods such as dromaeosaurs and troodontids, terrestrial predators that were fleet-footed hunters. The origin of birds is a classic example of two kinds of macroevolution: the phylogenetic origin of the group, and the sequential assembly of adaptations such as flight that are indelibly associated with birds. These adaptations were not assembled all at once. Rather, a great many characteristics associated with birds and flight first appeared in non-avian dinosaurs, where they were used for many purposes other than flight. These included insulation, brooding, and probably display and species recognition. Birds diversified steadily but gradually after their origin, which is identified with the origin of flight (Archaeopteryx); forelimb and other flight-associated features evolved more rapidly than features associated with the posterior skeleton. The first birds grew more slowly than extant birds do, and more like other small Mesozoic dinosaurs; like them, they probably matured sexually well before they completed their active skeletal growth. The origin of flight is not a problem of “trees down” or “ground up,” but rather an examination of the order in which diagnostic flight characters evolved, and what each stage can reveal about the functions and habits of bird outgroups at those evolutionary junctures.

Well worth checking out by those who might not otherwise peruse the foreign literature.