ch.9 - adam and angela

Chapter 9 - Evolutionary Path Making and Natural Drift


Neo-Darwinism remains the dominant mode of thought in evolutionary biology, characterized by notions of natural selection shaping development of species through selection. The idea of fitness in the evolutionary sense is usually expressed in terms of abundance (the number of offspring, or rate of growth of a population), or persistence (probability of extinction). There are several points of contention with this model, namely: Pleiotropy (genes are interdependent, making it difficult to discuss adaptation of individual traits); punctuated equilibria (drastic discontinuity and global rearrangement in the development of species); the importance of development (morphogenesis) of individual organisms; the fact that many groups remain genetically static for long periods of time (despite changing environments); and the many candidates for what the unit of genetic selection should be.

"The central issue remains whether evolutionary processes can be understood by the representations idea that there is a correspondence between and environment provided by the optimizing constraints of survival and reproduction"(pg.193-194)

The idea of organisms adapting to a pregiven environment (which is parallel to a cognitive system representing a pregiven, external world) is called into question, and a switch from optimization (prescriptive) to satisficing (proscriptive) is suggested. Selection is not the central agent of change, forcing development into a specified optimal path, but a pruning method by which multiple paths are kept viable. In this model, environment and organism specify each other in an ongoing enfolded process. In parallel, the role of Enactive Cognitive Science research is to understand how the mechanisms of structural coupling unfold and how regularities in environment and cognizing systems arise.

"..living beings and their environments stand in relation to each other through mutual specification or codetermination"(pg. 199)

"nature versus nurture will actually to go away unless we learn to see organisms and environments as mutually unfolded and enfolded structures."(pg. 199)

"...intelligence shifts from being the capacity to solve a problem to the capacity to enter into a shared world of significance."(pg. 207)

An example is given in the research of Rodney Brooks – who states that representation is the wrong unit of abstraction for intelligent systems, that we must incrementally built up intelligent capacity, that each step should build a complete intelligent system with real sensing and real action, and that the proper mode of viewing perceptive and active subsystems is through orthogonal division - division by activity rather than function. That is, there is no distinction between peripheral and central systems.