摘要:

AbstractThe radical alternative hypothesis of B. G. GARDINER (1982) and S. LØVTRUP (1985) in which birds are considered to be the sister‐group of mammals is examined from the point of view of paleontology. The hypothesis is absurd and in opposition to the phylogeny of the Amniota.ZusammenfassungDie radical alternative hypothesis von B. G. GARDINER (1982) und S. LBVTRUP (1985), bei der dieVogel als Schwestergruppe der Saugetiere betrachtet werden, wurde aus palaontologischer Sicht gepriift. Die Hypothese erweist sich als absurd und steht im Gegensarz zur Phylogenie der Amnio

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00909.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractA scrutiny of the literature shows that the ctenophoreHaeckelia (= Euchlora) rubahas only kleptocnidae and thatHydroctena salenskiiis a ctenophore without special cnidarian affinities. The “missing links” between cnidarians and ctenophores have thus turned out to be based on misinterpretations and must be excluded from future discussions on phylog

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00910.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractPrevious studies established the existence of morphologically highly similar amphiatlantic populations of the predominantly interstitial genusMicrophthatmus(European coastline ‐ from the German Bay to the Bay of Biscaya; American coastline ‐ from Maine to Massachusetts and at the coast of North Carolina). Originally these three populations were seen as belonging to a single species. By using a broad spectrum of different methodologies for character investigations (especially through the use of electron microscopy) three, distinct species can now be distinguished:M. listensisWestheide 1967,M. nahantensisn. sp. andM. carolinensisn. sp. While habitat structure and external morphology ‐ generally important in polychaete systematics ‐ were found to be rather similar between the three species, this study uncovered distinct differences between the species in their internal organization. Such sharp differences could even be followed down to the ultrastructure of single cells (e. g. copulatory stylets, position and number of ovaries, sperm and secretory granules of male accessory glands). Within population character variability is significantly lower in several features ofM. carolinensisthan in the same characters of the other two species. Similarities as well as differences have been noted in behavioural features and population dynamics between the

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00911.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractGenetic change‐overs inDrosophilapopulations similar to those frequently observed in microbial ones maintained in chemostats are described. In two cases, the change‐overs were revealed by an abrupt and sustained increase in the probability that two independently sampled lethal chromosomes proved to be allelic. These favored lethals (or closely linked non‐lethal elements) were estimated to have fitnesses 1.30–1.35 in combination with “ordinary” lethals or 1.05–1.10 in combination with non‐lethal chromosomes (fitness 1.00 is assigned to carriers of non‐lethal chromosomes only). A decrease in the frequency of lethal chromosomes in a third population was adequately explained by postulating the origin of a non‐lethal “favored” element whose relative fitness was 1.25, a value similar to those estimated above. Genetic change‐over in populations is discussed in relation to biochemical and m

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00912.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractDendrobatid frogs perform a unique mode of parental care, ranging from egg attendance and tadpole transport to tadpole feeding. It is hypothesized that a behaviour in which the egg attending parent remains with the cluch is the most primitive condition. In more advanced forms or parental care, the male is able to attend several clutches of eggs. Tadpole attendance and feeding, finally, started as deceit; the male induced the female to lay eggs into a bromeliad leaf axil already occupied by a larva. Costs and benefits of the different modes of parental care and possible alternative reproductive tactics are discussed.

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00913.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractMacromorphology and encephalization (EI) of brains were compared in 58 Vespertilionid species, brain composition in 36 species: 46 or 27 species of Vespertilioninae, 8 or 5 species of Miniopterinae, 2 species of Kerivoulinae, and 2 species of Nyctophilinae. Subfamily differences were found in the extent of the cover of the mesencephalon. It is nearly fully covered inKerivoula papulosa(Kerivoulinae), at least half covered (by the cerebellum) in Miniopterinae, and free (completely or nearly so) in Nyctophilinae and Vespertilioninae. In relative brain size, the Kerivoulinae are highest (average EI = 130), followed by the Miniopterinae (111), Nyctophilinae (102) and Vespertilioninae (95). The higher encephalization of Kerivoulinae and Miniopterinae is accompanied by a marked increase of relative size in cerebellum and striatum, and in Kerivoulinae, in hippocampus and neocortex as well.

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00914.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0947-5745    

DOI:10.1111/j.1439-0469.1987.tb00915.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY