EARLS, K.D.: Skeletal diversity and morphology in Anseriformes: an explicitly phylogenetic analysis Birds are very conservative in their overall morphology, and yet have diversified across a remarkable spectrum of locomotor behaviors. The associations of morphology with locomotor specializations have been murky, however, due to a lack of resolution within and among many avian clades. While […]

BOSTWICK, K.S.: Sexual selection for wing-sounds associated with convergent wing shape evolution between three clades of manakins (Aves: Pipridae Males of most of the ~40 species of Neotropical manakins (Aves: Pipridae) perform energetic courtship displays on lek territories. In nearly half of the speices, males produce mechanical wing sounds during these displays. Recent phylogenetic hypotheses […]

Niewiarowski, P.H.*; Angilletta, Jr., M.J.; Leache, A.D.; Porter, W.P.: Phylogenetically-based Comparative Analysis of Life History Variation Among Populations of Sceloporus undulatus The eastern fence lizard, Sceloporus undulatus, is one of the most widely distributed lizards in North America. Across its range, populations display two- to three-fold variation in many life history traits, including age at […]

WARNER, D.A.*; ANDREWS, R.M.: Maternal and Environmental Contributions to Hatchling Phenotypes and Survival of the Lizard Sceloporus undulatus Phenotypic variation of hatchling reptiles is influenced by environmental conditions during egg incubation and by various maternal sources. We investigated the effects of incubation moisture conditions, maternal yolk investment, and clutch on various phenotypic traits and subsequent […]

HALL, M.I.: Another look at Leuckart’s Law Birds have particularly large eyes relative to their body mass when compared to other vertebrates. This has been hypothesized to be an adaptation for flight because increases in axial length of the eye enhance spatial resolution, possibly improving an animal’s ability to judge distances, of obvious importance for […]

WOURMS, J.P.: Rudimentary trophotaeniae of Ataeniobius embryos: an evolutionary intermediate of teleost trophotaenial placentae. Embryonic trophotaeniae, external hindgut derivatives, and the maternal ovarian epithelium comprise the trophotaenial placenta of goodeid and other fishes. For 60 years, Ataeniobius toweri was considered the only goodeid fish whose embryos lack trophotaeniae. Scanning EM, however, reveals three, external, rudimentary […]

GALIS, F.: Modularity and the conservation of characters determined in the phylotypic stage The phylotypic stage is the developmental stage at which vertebrates most resemble each other. In an earlier study we found support for Raff’s hypothesis that the remarkable conservation of the phylotypic stage in vertebrates is due to the high number of ongoing […]

MCCLINTOCK, J.M.*; JOZEFOWICZ, C.; CARLSON, R.; MANN, D.J.; PRINCE, V.E.: Hox gene patterning and fish evolution We are using the zebrafish to investigate the evolution of Hox gene patterning functions. Whereas tetrapods possess 4 clusters of Hox genes, zebrafish have 7 distinct clusters. This condition is most likely due to a whole genome duplication, which […]

JEFFERY, J.E.*; BININDA-EMONDS, O.R.P.; COATES, M.I.; RICHARDSON, M.K.: Heterochrony in Amniote Evolution Heterochrony is thought to be a major link between developmental mechanisms and the emergence of phenotypic difference above the species level (macroevolution). Heterochronies affecting the timing of discrete events are of particular importance during organogenesis. Within vertebrates, this is the mid-embryonic period when […]

SHAPIRO, M.D.: Developmental morphology and gene expression in lizard digit reduction Evolutionary digit loss in lizards has been attributed to truncations in ancestral developmental programs, while another hypothesis refutes this idea. However, neither hypothesis has been tested in a developmental framework. Among living tetrapods, Australian skinks may offer the best examples of graded limb reduction. […]