ABSTRACT
Nest recognition is critical to the sociality of wasps. Studies on Polistes have shown that is essentially based on chemoreception. Moreover, wasps are also able to recognise the nest's contents and this could also participate in nest recognition. By the method of the artificial nest adoption, we examined which natural nest stimuli (hydrocarbons from paper nests, hydrocarbons from immature broods or eggs, and the physical presence of both) act consistently in nest recognition. Since these stimuli change with the age of colony, we also considered its maturity. Our results show that the presence of eggs have a stronger effect to induce artificial nest adoption. Surprisingly, the paper nest hydrocarbons alone were weakly attractive. On the contrary, paper nest hydrocarbons combined with immature brood hydrocarbons, increased significantly the adoption of artificial nests. Finally, previous experiences of the wasps and the maturity of the nest they come from appear as influential factors in adoption and probably in nest recognition. In conclusion, some biological and practical implications of these results are discussed that underlined the necessary combination of various nests features to insure nest recognition.
ABSTRACT
A copper-mediated procedure for terminal alkynyl-propargyl coupling has been applied to "skipped" bis-terminal undecatetrayne and 1,4-bis(pseudo)halobut-2-ynes with the aim of preparing ring carbomers of representative strained and loose cycloalkanes, namely [N]pericyclynes. Two unprecedented, cyclic. "skipped" polyynes with CH2 vertices have been isolated as mixtures of diastereoisomers: an isomer 1b and a dimer 2a of [5]pericyclyne 1a. The isomer 1b is a cyclotetrayne with an exocyclic allene function resulting from a unique formal SN process. Its structure has been established by 1H/13C HMQC and HMBC two-dimensional NMR analysis. According to density functional theory calculations, it is about 6 kcalmol(-1) more stable than [5]pericyclyne (1a). Compound 1b can also be regarded as a C13-relaxed [4]pericyclyne, a long sought "skipped" C12 tetrayne. The dimer 2a is a C30 ring that results from a formal SN process. It is a stable ring carbomer of cyclodecane, that is, a [10]pericyclyne, with four CH2 vertices.
ABSTRACT
The role of behaviour in biological evolution is examined within the context of Darwinism. All Darwinian models are based on the distinction of two mechanisms: one that permits faithful transmission of a feature from one generation to another, and another that differentially regulates the degree of this transmission. Behaviour plays a minimal role as an agent of transmission in the greater part of the animal kingdom; by contrast, the forms it may assume strongly influence the mechanisms of selection regulating the different rates of transmission. We consider the decisive feature of the human species to be the existence of a phenotypical system of cultural coding characterized by precision and reliability which are the distinctive feature of genetic coding in animals. We examine the consequences for the application of the Darwinian model to human history.
Subject(s)
Ethology , Evolution, Molecular , Genetics, Behavioral , Selection, Genetic , Animals , Cultural Characteristics , Genetic Code , Humans , Models, Genetic , Phenotype , Species SpecificityABSTRACT
A distinction is made between two definitions of animal cognition: the one most frequently employed in cognitive sciences considers cognition as extracting and processing information; a more phenomenologically inspired model considers it as attributing to a form of the outside world a significance, linked to the state of the animal. The respective fields of validity of these two models are discussed along with the limitations they entail, and the questions they pose to evolutionary biologists are emphasized. This is followed by a presentation of a general overview of what might be the study of the evolution of knowledge in animals.
