Brain, Sociobiology, and Evolution in Primates

Socialization in primates can be understood essentially as a function of the information processing ability of the CNS, which can be roughly measured in terms of relative brain size in closely related species groups. Both the cephalization constant (Hemmer 1971, 1974) and the extra neuron number (Jerison 1964, 1973) may be used for relevant quantification, as there is a highly significant correlation of both parameters in primates (7 ape species: r = 0.97, 20 Old World monkey species: r = 0.99; Hemmer 1978). The author has shown in a previous paper (Hemmer 1979) close negative correlations of relative brain size and the social organization as expressed in troop size (r = −0.92) and of relat…

Rhythmische Änderungen der Reaktion auf verschiedene olfaktorische Reize beim Krallenfrosch (Xenopus laevis)

The behavioural response ofXenopus laevis to olfactory cues shows different rhythmical oscillations which do not depend on the chemical nature and the concentration of the stimulus itself. Habituation to such cues occurs very slowly, pointing to their special importance in the feeding behaviour of this species.

Zur Frage genetischer Grundlagen bei Geweihmißbildungen des Rehes (Capreolus capreolus)

Die Untersuchung von in der Rehpopulation eines Revieres haufig auftretenden Geweihmisbildungen ergibt, das solche Deformationen der Geweihe in bestimmten Fallen indirekt erblich sein konnen, indem sie durch endogene Storungen in den Zentren fur Geweihtrophik versursacht werden.

Selection in captive populations

We have briefly reviewed types of genetic variation and selection in the wild as contrasted with selection in captive populations, along with the objectives of captive breeding programs, before recommending selection procedures for the genetic management of captive populations. Although some inadvertent selection for tameness and adaptation to captive environments is inevitable in captive populations, any selection that is actively applied to captive populations should have clearly defined objectives. Much of the apparent disagreement about genetic management of captive populations probably stems from the varying objectives of different captive breeding programs. Objectives differ depending…

Analyse des akustischen Geschlechtererkennungsmechanismus (Befreiungsrufe) bei Kröten (GenusBufo)

The release calls of male European toads (B. bufo L.,B. calamita Laur.,B. viridis Laur.) have been described and recorded in the form of spectrograms and oscillograms. While only 1 type of release call is uttered byB. bufo, inB. viridis andB. calamita 2 and 3 types respectively were found. The latter 2 species show a close relationship,B. calamita being the most highly developed toad in Europe.

Die Bedeutung des Serumeiweissbildes zur Diagnose vonBufo calamita Laur.,Bufo viridis Laur. und deren Bastarden (Amphibia, Anura, Bufonidae)

Electrophoretic investigations of the serum protein patterns of natterjacks (Bufo calamita Laur.) from the Iberian Peninsula and from Western and Central Europe, and of green toads (Bufo viridis Laur.) from Central Europa, Asia Minor and North Africa show that the two species differ disctinctly in the position of their albumin fractions. The identification of problematic specimens can result from the production of mixed serum with specimens of both species. As the albumin fraction of hybrids is doubled according to this method, it is also suitable for demonstrating the existence of such hybrids in natural populations.

Intraspezifische Unterschiede der relativen Hirngrösse beim Löwen (Panthera leo L.)

Different stages of brain evolution expressed by the allometric relation of3√ brain capacity and basal length of the skull are shown to be existent in the speciesPanthera leo. Whereas Asiatic lions obviously have the same level of brain size as leopards (Panthera pardus), African lions have higher brain capacities. A third level seems to be represented by the upper pleistocene American lion,Panthera leo atrox. These results permit us to reject some conceptions ofHerre andRohrs13 concerning the quantitative expression of mammalian brain evolution.

The Years in Mainz — II

Man's strategy in domestication - a synthesis of new research trends.

The minimum brain size possible in the relevant wild species and certain colour types which, because of alterations in the neurotransmitter system caused by the respective colour genes, are related to behavioural traits diverging from the wild animal's norm appear to be first-rate bases for domestication either separately or in combination.