Research on Virtual Creatures ( Virtual Life)

A Proposal by Ivan Tanev & Tom Ray

Vision

The products of natural adaptive systems (such as living nature and the human mind) vastly exceed the complexity of anything created by humans. Only when we identify and harness the principles behind natural adaptive systems will we be able to create human artifacts of similar adaptive complexity. Several decades of exponential growth in computing power has brought us to the threshold of a new era in computation and has led to the ubiquitous presence of computing machines containing vast numbers of components. The luxury of this rich bounty of computing elements invites the creation of new paradigms in computation. The traditional and still ubiquitous Von Neumann computer is rigid and brittle. By its very design, it lacks the robust and adaptive quality of living organisms evolved and grown from genomes. Cross-fertilization between biology and computer science has opened the era of evolvable software and hardware, while at the same time the development of re-configurable chips is blurring the distinction between hardware and software. In a world where both genomic information and digital computing elements have reached the explosive phase of their exponential growth, where life can be seen as a form of computation and some forms of computation can be seen as life, where evolution can inhabit both the organic and the digital medium, an era of active exploration of fundamentally new, and often biologically inspired computer architectures has begun.

Objectives

1. Biologically inspired engineering – To use biologically inspired concepts in order to achieve virtual creatures (embodied software agents) and/or robots (VC&R) that are:

· Better performing, aesthetically and/or functionally

· Faster and more richly evolving

· More robust and adaptive

· More efficiently implemented in hardware

2. Computational models of biology – Investigating the features and properties of VC&R to understand, verify, anticipate and digitally evaluate incomplete or unproven theories and hypotheses in molecular, evolutionary and developmental biology.
3. Virtual pets – Further develop the potential of Virtual Life as a kind of virtual pet for human entertainment, and to explore the emotional and empathetic interactions between humans and VC&R.

Research Directions

The ability of VC&R system to evolve both morphology and behavior, situated in realistically simulated environments, offers the opportunity to conduct research in many directions, including the following:

1. Morphogenesis – The rich morphology of VC&R allows exploration of many phenomena:

· Symmetry – the evolution/emergence of planes of morphological symmetry in natural species (fighting gravity? locomotive efficiency? genome compression? optimum performance? checksum for tolerance to partial genetic damage? ...)

· Epigenesis – development of VC&R through variable gene expression mechanisms

· Allometry – growth of a part of an organism in relation to the growth of the whole organism or some part of it

· Heterochrony – a genetic shift in timing of the development of a tissue or anatomical part, or in the onset of a physiological process, relative to an ancestor

· Parsimony principle – applied to sensory abilities of VC&R (e.g. smell vs. color vision)

2. Multi-agent-systems – development of multi-agent VC&R allows exploration of a variety of phenomena:

· Differentiation – how functional specialization in multi-agent VC&R builds morphological specialization

· Polymorphism – the comparative study of the presence of two or more distinct phenotypes in a population due to the expression of different alleles of a given gene

· Polyphenism – polymorphism due to environmental changes

· Epigenesis – polymorphism and polyphenism through epigenesis using controllable histone code and/or genetic regulatory networks

· Communication – the emergence and survival value of morphological traits, relevant to signaling among VC&Rs

· Coevolution – study of evolutionary interactions between multiple populations sharing an environment

· Social behavior – study of cooperative, competitive, amorous and other interactions between individuals of the same “species”

3. Biological Modeling – investigating and comprehending incompletely or poorly understood phenomena seen in the nature (midair turns of flying snakes, rollovers of falling cats, etc…) and considering their impact on the development of modern technology.
4. Automated Design – VC&R systems can serve the purpose of automatically designing optimal morphology for VC&R intended to perform in desired ways in anticipated environments (optimal design of flying, swimming, rolling or walking mechanisms).
5. Mood and Emotion – As we learn more about the chemical organization of the brain and the human mind that emerges from it, we will use our knowledge to develop digital analogies to the chemical modulation of neural circuits. This should allow the introduction of neural mechanisms and processes similar to moods and emotions.
6. Brain Building – VC&R might be used to develop the software architecture and to simulate the behavior of an artificial brain. VC&R have the following qualities relevant to brain building:

· Directed graph – VC&R systems utilize a flexible and powerful directed-graph representation of both morphology and neural circuitry.

· Evolvable – The neural circuitry of VC&R is completely distributed, arbitrarily complex, yet seemingly highly evolvable.

· Universal controller architecture – The directed graph of the neural circuitry defines the connectivity of the sensory inputs, the output actuators, and the processing elements, and may be considered to be a universal paradigm for building robot controllers.

· Hardware evolution – Such a nervous system might have a straightforward mapping into hardware, suggesting a possible implementation of artificial brain as an evolvable hardware.

7. Virtual Pets – evolved VC might be considered as components of an artificial environment, promoting psychological well-being. For example, the results of recent research suggest a strong correlation between the level of specific hormones in bloodstream with the degree of the feeling of trust in human; and between the degree of the trust in society and the social and economical prosperity of society. We presume that the environment plays a significant role in hormonal regulation, and that the environment can be synthetic, digitally evolved, and may feature a population of evolved VCs, shaped by the selection pressure determined by the direct biological feedback from human beings. Evolved virtual pets might contribute to psychological health.

Required Resources

1. Physics Engine – The proposed research will be built on the software foundation of the Virtual Life system. The Virtual Life software uses the Math Engine physics library, which is not suitable for future development because: it is no longer available, it contains a serious memory leak and it does not provide contact detection. Physics engines are reviewed at: http://www.dai.ed.ac.uk/homes/timt/research/embody.html. We have tentatively chosen to use the Open Dynamics Engine (http://opende.sourceforge.net/) written by Russell Smith, which is freeware, open source.