MCBRATNEY, Brandeis M. ; MORRISS-KAY, Gillian M.; Harvard University, Cambridge, MA; University of Oxford, Oxford, UK: Neural Crest and Mesoderm Contributions to the Mammalian Cranial Base The cranial base is the oldest part of the vertebrate skull, thus understanding variations in tissue origins among vertebrate basicrania may clarify the developmental basis of variations in craniofacial […]

DRAKE, Abby G; University of Massachusetts Amherst: Heterochronic Evolution in the Skull Morphology of Canids Landmark-based three-dimensional morphometrics are utilized to investigate heterochronic mechanisms within the skull morphology of the genus Canis. Following the strict definitions of Gould (1977) and Alberch, et al. (1979), perturbations in three developmental parameters, growth (size), development (shape), and age […]

THOMAS, K.R.; University of Chicago: Evolutionary conservation and modularity in the cranial ossification sequences of ostariophysan fishes This study documents the ossification sequence of skull bones in two ostariophysan species and attempts to address two questions: 1) How conserved are cranial ossification sequences among ostariophysan fishes? and 2) Is there evidence for modularity in the […]

DAVIDOWITZ, G*; D’AMICO, L.J.; ROFF, D.A.; NIJHOUT, H.F.; University of Arizona; Duke University; Univ. of California, Riverside; Duke University: The physiological regulation of insect body size Remarkably little is known about the developmental and physiological mechanisms that determine body size, or about the mechanisms by which an organism translates different environmental signals that result in […]

GALIS, F.; STEIGENGA, M.; RUINARD, S.; Leiden University, The Netherlands: THE CONSTANCY OF CERVICAL VERTEBRAL NUMBER IN MAMMALS: EVIDENCE FOR STRONG STABILIZING INTERNAL SELECTION Mammals have a remarkably constant number of 7 cervical vertebrae, unlike the number of vertebrae of other regions which have a variable number. We proposed a hypothesis some years ago that […]

MARCUS, JM*; MONTEIRO, A; SUNY at Buffalo: Progress in the development and evolution of lepidopteran color patterns Butterfly wing color patterns are among the most attractive model systems for exploring the relationship between development and evolution because they are highly variable, consist of clearly defined subunits, are structurally simple and at least some patterns are […]

MADERSON, PAUL F.A.; Brooklyn College of CUNY: Old theories die hard – but cells move only one way in growing feathers Feather development and replacement are complex phenomena. Classical histological studies showed that apical tissues were first-formed and interpreted growth to involve proximo-distal movement of cells away from basal germinal locations. The Chicago School’s “Concrescence […]

LARSEN, E.W.; CHEUNG, U.; DWORKIN, I.; Univeristy of Toronto; University of Toronto; University of Toronto: Designing: an approach to evolutionary developmental biology Why are morphological traits highly constrained in some taxa but widely varying in others? Arthropod segmentation is a case in point, myriapods and crustacea vary in numbers of segments whereas insects are said […]

GUIASU, R. C. * ; DUNHAM, D. W. ; Univ. of Toronto, Toronto, Canada ; Univ. of Toronto, Toronto, Canada : The ecology, behaviour, and conservation of the vulnerable burrowing crayfish Fallicambarus fodiens (Decapoda, Cambaridae) Fallicambarus fodiens is a semi-terrestrial, burrowing crayfish species, whose entire Canadian distribution is restricted to only a few wetlands in […]

SIMANDLE, E.T.*; TRACY, C.R.; University of Nevada, Reno; University of Nevada, Reno: The Mane Question: Untangling why lions have it Lions (Panthera leo) are unique among felids, in that most males possess a conspicuous mane. For over a century, researchers have speculated that the lion�s mane may confer certain costs or benefits with respect to […]