Categorically organized knowledge is the main vehicle in high-level cognitive processes. The previous empirical and theoretical studies on categorization paid almost exclusive attention to how individuals learn categorical knowledge. In the real world, however, people acquire knowledge not only through individual learning, but also through interacting with others. In the present study, using co...

Most researchers in the science of the origin of life assume that the process of living is nothing but computation in the chemical domain, i.e. information processing of a genetic code. This has had the effect of restricting research to the problem of stability, as epitomized by the concept of the hypercycle and its potential vulnerability against parasites. Stability is typically assumed to be...

Artificial life has now become a mature inter-discipline. In this contribution, its roots are traced, its key questions are raised, its main methodological tools are discussed, and finally its applications are reviewed. As part of the growing body of knowledge at the intersection between the life sciences and computing, artificial life will continue to thrive and benefit from further scientific...

Evolutionary adaptation to a new environment depends on the availability of beneficial alleles. Beneficial alleles may appear as new mutations or may come from standing genetic variation—alleles already present in the population prior to the environmental change. Adaptation from standing genetic variation in sexually-reproducing populations is expected to be faster than from new mutations becau...

It is tempting to be confident that we know how biological evolution works. After all, we know a mechanism capable of producing adaptation, and we understand the necessary and sufficient conditions for this to occur, and those conditions are met in natural populations – the rest is surely just details. However, there can be many different algorithms that utilise a given underlying mechanism (su...

Mental representation is a fundamental aspect of advanced cognition. An understanding of the evolution of mental representation is essential to an understanding of the evolution of mind. However, being a decidedly mental phenomenon, its evolution is difficult to study. We hypothesize how interactions between adaptation levels may cause emergence of isomorphism between a cognitive system and its...

Open-ended evolutionary systems offer us the tantalising prospect of creating artificial life from simple precursors. One of the issues in designing open ended systems is that there exist few metrics for measuring their evolutionary activity. Current measures of evolutionary activity are only applicable to systems in which the fitness of a single component is defined by an explicit fitness func...

Temporal polyethism is a method of division of labor exhibited by many eusocial insect colonies, where the type of task an individual attempts is correlated with its age. The evolutionary pressures that give rise to this widely-observed pattern are still not fully known. The long generation times of eusocial insects combined with the complications associated with performing artificial selection...

streptokinase is a potent fibrinolytic agent which is widely used in treatment of deep vein thrombosis (dvt), pulmonary embolism (pe) and acute myocardial infarction (mi). major limitation of this enzyme is its short biological half-life in the blood stream. our previous report showed that complexing streptokinase with chitosan could be a solution to overcome this limitation. the aim of this re...