The evolution of vertebrates signalization systems: factors, forms and basic tendencies. - V.S. Friedmann. - Berkut. 17 (1-2). 2008. - P. 79-157.
We investigated features of vertebrates signalization systems evolution. There are two groups of such features for different levels of communicative system progress motivational signals and referential signals. Demonstrations for motivational signals (releasers) play a role of motivation level and following animal behavior indicators. Demonstrations for referential signals have an external referent and reflect alternative categories of problem situations, which are generated in interaction. These categories are «names» of different situations and programs to solve them. Motivational signals force something to react as it necessary for next process stage. Referential signals let something to choose its reaction freely. They are arbitrary signs in its structure and function. Ritualisation is an evolutionary process, which turn the individual expressions, provoke with arousal in situation «conflict the interests», in species-specific signals; their meaning promote the solution all this situations or support more effective actions in solution this conflict in own interests. Contrary opinion classical ethologists it is showed that ritualization process consists in two distinct stages. The first stage is the ritualization in true sense – the transformation individuals expressions, intention movements, and other «demonstration precursor» in complete system of species-specific ritualized demonstrations used in threat, combat, courtship, danger warning and other contexts. The demonstrations are organized in rows and placed along the specific motivational gradients so the different demonstrations this row convey the different level of aggression, alarm, fear, risk, sexuality and other motivational conditions which connect with interactional situations. So appear some systems of motivational signals. The demonstration at this stage in their communicative function are similar with pantomime, not signs – there are signals of motivation lever and intentions the animals, their forms is not steady and vary connectly with dynamic of motivation conditions a.o. The second stage of ritualization process we can name «signification» because during this on the base of former demonstration row develop the sign system, every demonstration develop into sign, support the information change in interaction this context, old motivational signals develop in referential signals with keeping homologues in signal forms but increasing the stereotypy and differentiation between signals. During the second stage of ritualization faintly differentiated forms of former motivational signals in ancestor species this clade evolved into discrete forms of referential signals in derived species, which are well-differentiate and contrasts with one to another as the logical oppositions. As this process will complete, all demonstrations next stage get true signs, are independent from motivation underground and mark different essential situations, which can appear in interaction the animal with their outer world. On this stage different elements in row of referential signals «name» the different essential elements of animals’ outside in this specific communication process such as counteracting demonstrations of other animal in the threat, combat, territory defence, courtship etc., or different classes of raptors, or different kinds of food. The referential signals as signs of essential communicative situations in animal’s outward are comparable with sign systems in men communication for example the gestures in sign languages. They inform all interaction’s participants about some possibilities in solution the conflict of interests and/or motivation conflict through change the behavior model which will be effective against this opponent but not manipulate its behaviour. In contrary the motivational signals are specific stimulus which manipulate the opponent’s and reduce to react so as in needed on the next stage of behavioral process. Further we investigate the question: what is the role of demonstrations in social interaction of birds before developing their signal functions, on the first stage of ritualization process? We prove that this period the courtship or agonistic demonstrations were used as a specifical barrier prevented immediate rapprochement the participants. Due to ritualized demonstration change they remain from directed aggressive or sexual actions one to each other. The demonstration freeze the rapprochement on the period required from doing the signal and releaser effects of demonstration forms and participants «remove» the motivation conflict create during partner’s act on next stage of process. Without solution the motivational conflict in the «dance» of ritualized demonstration change both participants will be scarred and copulation or other interaction result will fail. For example, in successfully agonistic interaction threat demonstration must inhibit the direct attacking and escaping from participants so that the will be similar the increasing rate of restrain effect by further winner demonstrations and the decreasing rate of resistance possibility by further loser. The role of demonstrations as barrier lightening the motivational conflict in all participant in animal communication is similar of role the ritualized dances in sum men cultures, as was described by Konrad Lorenz still 1950’s. [Russian].
Key words: ethology, animal communication, signal, ritualization, demonstration, display.
Address: V.S. Friedmann, Laboratory of ecology and nature conservation, biological faculty, Moscow university, Leninskiye gory, 1/12, 119992 Moscow, Russia; e-mail: email@example.com.