PATTON, ML*; DEL CASTILLO, SM; BASHAW, MJ; J�CHLE, W; LAMBERSKI, N; BERCOVITCH, FB; Zoological Society of San Diego: Contraception in female giraffe with a GnRH analog (Deslorelin) Giraffe (Giraffa camelopardalis) are sensitive to inbreeding. A significant increase in infant mortality occurs when closely related animals are paired. In captivity, separation of the sexes is not […]
year: 2005
Comparative reproductive morphology in mammals a Darwinian perspective
ANDERSON, Matthew/J; Zoological Society of San Diego: Comparative reproductive morphology in mammals: a Darwinian perspective Sperm competition occurs when the gametes of two, or more, males compete for opportunities to fertilize a given set of ova. This phenomenon is most frequently observed in mammals possessing a multiple partner mating system where females mate with more […]
Vertebrate axial patterning and the consequences of duplication events
PRINCE, V.E.*; HURLEY, I; STOCKERT, J; HALE, M; University of Chicago; University of Chicago; University of Chicago; University of Chicago: Vertebrate axial patterning and the consequences of duplication events It has been proposed that genome duplications can provide genetic raw material for evolutionary transitions. Support for this hypothesis has come from studies of teleosts, which […]
Terminal Addition and the Evolution of Bilaterian Form
JACOBS, David/K; HUGHES, Nigel/C; WINCHELL, Christopher/J; UCLA; UC Riverside; UCLA: Terminal Addition and the Evolution of Bilaterian Form Diverse bilaterian taxa, including representative lophotorchozoa, ecdysozoa and deuterosomes, share aspects of a developmental process where repeated pattern elements are added posteriorly during differentiation. Developmental genetic data suggest that this process of �terminal addition� derives from a […]
Segmentation in Helobdella robusta, a glossiphoniid leech
WEISBLAT, D.A.; RIVERA, A.S.; GONSALVES, F.C.; SONG, M.H.; ZHANG, S.O.; Univ. of Calif., Berkeley; Univ. of Calif., Berkeley; Univ. of Calif., Berkeley; NIDDK, NIH; Univ. of Calif., Berkeley: Segmentation in Helobdella robusta, a glossiphoniid leech Leeches are a clade of hermaphroditic, segmented worms, classically regarded as one of three classes within Annelida. Compared to most […]
Posterior addition the annelid way
BALAVOINE, G; DE ROSA, R; PRUD’HOMME, B; ADOUTTE , A; CNRS, Gif-sur-Yvette, France; Univ. of Geneva, Switzerland; Univ. of Wisconsin, Madison; CNRS, Gif-sur-Yvette, France: Posterior addition: the annelid way The question of the origin of metameric segmentation in metazoans has become a heated debate in recent years, with some gene expression data suggesting that it […]
Ecological and phylogenetic variation in segmentation in snakes
HEAD, J. J.; Smithsonian Institution: Ecological and phylogenetic variation in segmentation in snakes Ecological influences, phylogenetic history, and the evolutionary mechanisms driving segment numbers in snakes are poorly understood, despite recent interest in the paleoecology of snake origins and their early evolution. I employ statistical and morphometric methods to examine the relationship between ecology, phylogeny, […]
Segment number and segmentation performances in arthropods
FUSCO, G.; University of Padova, Italy: Segment number and segmentation performances in arthropods In arthropods, developmental mechanisms of segmentation are very diverse and differently associated with growth, both with respect to developmental time and with respect to the spatial localization of segment origination in the embryo or in the larva. Although mechanisms of segment specification […]
Historical Experiments in Terminal Growth, Segmentation and Body Plan Regionalization
HUGHES, Nigel C.; Univ. of California, Riverside: Historical Experiments in Terminal Growth, Segmentation and Body Plan Regionalization Terminal growth is apparent in those fossilized organisms in which progressive incremental change in the morphology of the posterior region occurred during development. It is recognized in fossils via the pattern of appearance of discrete structures, such as […]
Genetic, developmental and environmental aspects of variation in centipede segment numbers
ARTHUR, Wallace; CHIPMAN, Ariel; National University of Ireland, Galway; University of Cambridge: Genetic, developmental and environmental aspects of variation in centipede segment numbers In some groups of centipedes, the number of segments is fixed. In others, notably the order Geophilomorpha, it is variable. The variation in this particular group has both within and between species […]
