摘要:

The family Formicidae is redefined on the basis of all common characters shared by its members, which allows a hypothetical sketch of its unknown presumed ancestor. The first cladistic analysis is presented of internal ant phylogeny at the subfamily level, based on the 10 extant subfamilies commonly recognized in the literature. Although some weaknesses remain, this phylogenetic reconstruction shows several concrete improvements. None of the fossil subfamilies allow comparison with the recent subfamilies by neontological criteria. Among recent subfamilies no autapomorphic characters have been found for the Aneuretinae which clearly show only primitive character states easy to identify by comparison with the Dolichoderinae. The former subfamily has been regarded as a straightforward synonym of the latter. The Ponerinae have been still characterized tentatively on the basis of two weak synapomorphies but the real monophyly of its members appears to be questionable. The subfamilial phylogeny, as a whole, appears relatively weakly documented on several branchings with exception of the Nothomyrmeciinae, Dolichoderinae, and Formicinae on one side which can be easily opposed to all remainder recent subfamilies on the other side, by having a constriction after abdominal segments I and II only instead of after segments I, II, and III. Another important conclusion reached in this paper concerns the Formicinae, which can no longer be considered as the most advanced extant ants.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525520

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The warbler communities of two marshland areas of north-western Italy with a partially different vegetation were studied for 3 years in order to determine their ecological organization, especially with respect to interspecific coexistence.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525521

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The technique of nest exchange was used both in the field and in the laboratory onPolistes gallicusto study the behaviour of foundresses in alien nests and the possible changes in the reproductive apparatuses of the workers emerging in the presence of foundresses other than their mother. In the field, nests built on shrubs were removed complete with their plant stems and fixed to plants where other nests had been removed. In the laboratory, foundresses were subjected to a cage exchange. Observation on foundresses at the moment of their first landing on the alien nests showed that these perform a particular behaviour, stroking the abdominal sternites on the surface of the nests and inside the cells with a probable release of secretions. Checks of the immature brood revealed a massive destruction of eggs in the alien nests. Dissection of the workers emerging in the nests in the presence of the alien foundresses indicated that the reproductive apparatus of these females was fairly developed and that most of them actually had eggs in their ovaries that were ready to be laid. These findings raise questions on the possible presence of regulatory pheromones of the queen in the colonies ofPolistesand on the evolution of interspecific social parasitism in these wasps.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525522

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Hamilton's rule is that an altruistic act shoud be performed whenrtimes the benefit to a recipient is greater than the cost to the donor, whereris a measure of the extent of genetic similarity at the locus determining the action. This rule applies when the action is conditional upon role. Roles X and Y are defined in terms of an asymmetry between the pair of interacting relatives; e.g. X and Y may be older/ younger, stronger/weaker, etc. To obey Hamilton's rule, roles must be assigned randomly with respect to the genotype of the pair of relatives, and a gene must be expressed in one role only; i.e. its expression must be conditional upon role. If gene action is unconditional so that a gene is expressed in both roles, the rule (at least in its simplest form) may not apply.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525523

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The present experiment was designed in order to look into the effects which exposure either to a demonstrator performing the task or to the task in itself had on young mouse's skill in solving a problem. Three experimental groups were organized. In the first group the pups spent 7 days with a demonstrator solving the problem; in the second one they spent the same amount of time with an adult unable to solve the problem. In the third group each pup spent 7 days with only the task at its disposal. At the end of this period all pups were tested to assess the degree of skillfulness reached during the training. Results showed that the animals with the demonstrator were the better performers in solving the problem.

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525524

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525525

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0394-9370    

DOI:10.1080/08927014.1989.9525519

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor