From Evo to EvoDevo: Mapping and Adaptation in Artificial Development

Abstract

Artificial development takes it's inspiration from the processes of biological development (Wolpert; 2002). The process of mapping genetic information in the genotype to a phenotype that express structure, behaviour and functions (Hall; 2003). In nature this is the processes making a zygote (fertilised egg) develop to a multicellular organism. As all living systems and their subsystems are evolved, developmental processes are also a product of evolution. In biological development, an initial unit – a cell, holds the complete building plan (DNA) for the organism. It is important to note that this plan is generative – it describes how to build the system, not what the system will look like. Units have internal state, can communicate locally, can move, spawn other units or die. Groups of units may also exhibit group-wise behaviour i.e. a group state. The developmental stages from the zygote to the multicellular organism, although interdependent and not strictly sequential, may be categorized as pattern formation; morphogenesis; cell differentiation and growth (Wolpert; 2002). Information carried in the ever evolving genome is the information that passes from generation to generation and the genetic information is contained within a cell that serves as both the constructor and construct of the phenotype. An important feature of natural development is that the developing organism develops and operates within an environment. The environment is not only the arena in which the behaviour and function of the organism unfolds, it is also an important source of information for the outcome of the developmental process. As stated, the genome may be considered information exploitable by the developmental process to “build” the organism. In biology the environment also serves as a source of information for the development of the organism. As such, the developmental process can include the environmental information as an input information source enabling adaptation through the developmental process. This implies that natural organisms include developmental plasticity, i.e. phenotypic plasticity (West-Eberhard; 2003). As such, the evolved organism is a product of the information in the genome, the present environment and the cellular developmental processes that is initialised in the zygote. Recently developmental approaches have once again come to the front in the area of bioinspired systems. The motivation for moving towards developmental system is multitudinous ranging from early work on self-reproduction (von Neumann; 1966), to more recent attempts in overcoming limitations in Evolutionary Computation (EC), e.g., scaling O pe n A cc es s D at ab as e w w w .in te ch w eb .o rg