Evolutionary processes and its environmental correlates in the cranial morphology of western chipmunks (Tamias).

The importance of the environment in shaping phenotypic evolution lies at the core of evolutionary biology. Chipmunks of the genus Tamias (subgenus Neotamias) are part of a very recent radiation, occupying a wide range of environments with marked niche partitioning among species. One open question is if and how those differences in environments affected phenotypic evolution in this lineage. Herein we examine the relative importance of genetic drift versus natural selection in the origin of cranial diversity exhibited by clade members. We also explore the degree to which variation in potential selective agents (environmental variables) are correlated with the patterns of morphological variation presented. We found that genetic drift cannot explain morphological diversification in the group, thus supporting the potential role of natural selection as the predominant evolutionary force during Neotamias cranial diversification, although the strength of selection varied greatly among species. This morphological diversification, in turn, was correlated with environmental conditions, suggesting a possible causal relationship. These results underscore that extant Neotamias represent a radiation in which aspects of the environment might have acted as the selective force driving species' divergence

Rationality and metacognition in non-human animals

The project of understanding rationality in non-human animals faces a number of conceptual and methodological difficulties. The present chapter defends the view that it is counterproductive to rely on the human folk psychological idiom in animal cognition studies. Instead, it approaches the subject on the basis of dynamic- evolutionary considerations. Concepts from control theory can be used to frame the problem in the most general terms. The specific selective pressures exerted on agents endowed with information-processing capacities are analysed. It is hypothesized that metacognition offers an evolutionary stable response to the various demands of the internal and external flows of information in a competitive environment. Metacognition provides a form of process-reflexivity that can, but does not have to be redeployed through metarepresentations. Finally the claim that rationality so conceived involves normativity is discussed

Collective Decision Making as the Actualization of Decision Potential

This paper presents some characteristics and dilemmas of collective decision making. Collective decision making could be presented as the process of successive crystallization of dominant alternatives under the influence of different decision contexts from primary given decision potentials. This process is presented as the many-phased process of the acting of contextually dependent "energizing factors" of the collective decision making on the "attractiveness matrix" of outcomes of collective decisions. The attractiveness matrix determines the attractiveness for each alternative of decision, and the most attractive alternative in the given situation presents the rational decision in the given situation. In the final phase of decision making holds a context which gets a simplified attractiveness matrix. It corresponds to the common decision for one of the alternatives.collective decision making, rationality, decision potential, joint outcomes, energizing