Search PubMed⌕ Search

Biomedical subjects

M A Bedau

Publications and source records attributed to M A Bedau.

6 recordsLinked to original sources
PubMed2000

Is Echo a complex adaptive system?

We evaluate whether John Holland's Echo model exemplifies his theory of complex adaptive systems. After reviewing Holland's theory of complex adaptive systems and describing his Escho model, we describe and explain the characteristic evolutionary behavior observed in a series of Echo model runs. We conclude that Echo lacks the diversity of hierarchically organized aggregates that typify complex adaptive systems, and we explore possible explanations for this failure.

Algorithms↗
PubMed2000

Open problems in artificial life.

This article lists fourteen open problems in artificial life, each of which is a grand challenge requiring a major advance on a fundamental issue for its solution. Each problem is briefly explained, and, where deemed helpful, some promising paths to its solution are indicated.

Artificial Intelligence↗
PubMed1999

Visualizing evolutionary activity of genotypes.

We introduce a method for visualizing evolutionary activity of genotypes. Following a proposal of Bedau and Packard [11], we define a genotype's evolutionary activity in terms of the history of its concentration in the evolving population. To visualize this evolutionary activity we graph the distribution of evolutionary activity in the population of genotypes as a function of time. Adaptively significant genotypes trace a salient line or "wave" in these graphs. The quality of these waves indicates a variety of neutral variation, and random genetic drift. We apply this method in an evolutionary model of self-replicating assembly language programs competing for room in a two-dimensional space. Comparison with fitness graphs and with a nonadaptive analogue of this model shows how this method highlights adaptively significant events.

Biological Evolution↗
PubMed1998

Four puzzles about life.

To surmount the notorious difficulties of defining life, we should evaluate theories of life not by whether they provide necessary and sufficient conditions for our current preconceptions about life but by how well they explain living phenomena and how satisfactorily they resolve puzzles about life. On these grounds, the theory of life as supple adaptation gets support from the natural and compelling way it resolves the following four puzzles: (a) How are different forms of life at different levels of the vital hierarchy related? (b) Is there a continuum between life and nonlife? (c) Does life essentially concern a living entity's material composition or its form? (d) Are life and mind intrinsically connected?

Animals↗
PubMed1997

Emergent models of supple dynamics in life and mind.

The dynamical patterns in mental phenomena have a characteristic suppleness--a looseness or softness that persistently resists precise formulation--which apparently underlies the frame problem of artificial intelligence. This suppleness also undermines contemporary philosophical functionalist attempts to define mental capacities. Living systems display an analogous from of supple dynamics. However, the supple dynamics of living systems have been captured in recent artificial life models, due to the emergent architecture of those models. This suggests that analogous emergent models might be able to explain supple dynamics of mental phenomena. These emergent models of the supple mind, if successful, would refashion the nature of contemporary functionalism in the philosophy of mind.

Animals↗