Decision making is one of the distinguishing properties of biosystems. Decision making of course does not necessarily mean conscious decision making, which is exclusively human. On the contrary, the ability to make decisions can be observed in every living organism even in unicellular species as a type of molecular logic, in the form of chemotaxis). Chemotaxis is chemistry-driven motility: towards areas of increasing concentrations of friendly chemicals (positive chemotaxis) and away from increasing concentrations of hostile chemicals (negative chmotaxis).
Tuesday, 10 December 2013
By definition, biological macroevolution is the hypothetical emergence of higher taxa (new classes, phyla, kingdoms) from the ones that exist at any given point in time, by itself, i.e. without recourse to intelligent agency. Many authors maintain that combinations of law-like necessary factors (such as natural selection) and stochastic factors (mutations, genetic drift and recombination in the case of sexual reproduction) are causally sufficient to explain hypothetical macroevolution.