Synthetic Lifeforms: What are the Types?

Synthetic life is a multi-disciplinary field in research devoted to the creation of lifelike structures in fields like computational, biochemical, mechanical, or combinations of the three. Scientists working in the field of artificial life anticipate gaining general insights about self-organizing systems, applying their knowledge in technology development.
Progress of Research in Synthetic Life

The historical and theoretical bases of this field are diverse. These include:
  • Early attempts to mimic the behavior of animals and humans by the invention of self-powered mechanical devices in the sixteenth century
  • Cybernetics, the study of informational control within machines and animals
  • Computer science as a theory and the idea of it being equivalent to providing logic for mechanical systems performance
  • John von Neumann's so-called self-replicating cellular automata
  • Computer science, along with computational architectures, as a set of technical practices
  • Artificial intelligence (AI)
  • Philosophy and system science notions of hierarchies
  • Robotics
  • Non-linear science, such as the physics of complex systems and chaos theory and theoretical biology
  • Evolution theories within biology
Despite the long history of the subject, the first international conference for synthetic life was not held until 1987. This conference was organized by C.G. Langton, a computer scientist, who presented a future synthesis of the field's various roots, and chalked out the important elements of the research program. During the first five and a half years after 1987, the research went through an exploratory phase, in which, it was not always clear by what criteria, one could evaluate individual contributions. Later, the field subdivided into clusters of research areas, each with its own representations, questions, and works in progress. As in A.I. research, some areas of artificial life research are mainly motivated by developing more efficient technological applications through the use of biologic inspired principles. Examples of these applications include: modeling architectures to simulate complex adaptive systems, like in traffic planning, as well as biologically inspired immune systems for computers. Other domains of research are driven by theoretical queries about the nature of emergence, the origin of life, and forms of self-organization, complexity, and growth.

Composition of Synthetic Lifeforms

Synthetic life might consist of three domains of development labeled as software, hardware, or wetware, or a combination of these three depending on the type of life required by researchers. Individual synthetic life is described in each of the three domains.

The field of computer science represents the idea that life is characterized by forms of organization, rather than by its constituent material. Thus, 'life', as we call it, may be comprehended in some form other than carbon chemistry, such as in a computer's central processing unit, or in a network of computers, or as computer viruses spreading through a network. Researchers can build a virtual ecosystem and let small component programs represent species of prey and predator organisms competing or cooperating for requisite resources like food. The difference between this type of artificial life and ordinary scientific use of computer simulations is that, with the latter, the scientist attempts to create a replica of a real biological system (like fish populations of the Pacific Ocean) and to base the description upon real data and established biologic principles. The scientist tries to authenticate the model to make sure that it represents certain aspects of the real world.

On the other hand, an artificial life model represents biology in a more conceptual sense; it is not a genuine system, but a virtual one, constructed for a specific reason, such as the investigation of the efficiency of an evolutionary progression of a Lamarckian type (based upon the inheritance of acquired characters) as opposed to Darwinian evolution (based upon natural selection among randomly produced variants). Such a biologic system is assumed to not exist anywhere in the real universe due to its idealistic approach.

As Langton emphasized, artificial life investigates 'the biology of the possible' to compensate for the inadequacies of traditional biology, which is bound to investigate how life actually evolved on our planet, but cannot pinpoint the borders between the possible and impossible forms of biologic processes. For example, a synthetic life system might be used to determine whether it is only by historical accident that organisms on our planet have a universal genetic code, or whether the code could have been dissimilar. There has been a debate as to if virtual life in the computer world is a model on a high level of abstraction, or is it a form of genuine life as suggested by some artificial life researchers. If it really is possible to create genuine life from scratch, the ethical concerns related to this research intensify: In what sense can the human community be said to be in charge of creating life by artificial means?

Hardware in artificial life usually refers to small animal-like robots called animats, that scientists build and use to study the design principles of autonomous systems. The functionality of an agent (a collection of modules, each with its own field of interaction and competence) is a property of the interaction of the system with its surrounding environment. The modules operate semi-autonomously and are solely responsible for the sensing, modeling, computing or reasoning, and motor control that is imperative to obtain their specific competence. The direct coupling of perception to action is facilitated by the use of reasoning logistics, which operate on representations that are relatively close to the information of the sensors. This method states that to build a system that is intelligent, it is necessary to have its representations in the physical world.

Representations do not need to be explicit, but must be situated and personified. The robots are thus, situated in a universe; and do not deal with abstract descriptions, but with the environment that directly affects the behavior of the system. Additionally, the robots have 'bodies' and experience the world directly, so that their actions have an instant feedback upon the robot's own sensations. Computer-simulated robots, on the other hand, may be placed in a virtual environment, but they don't have 'bodies'. Hardware-related artificial life has many industrial and military technological applications.

Wetware synthetic life comes closest to real biology. The scientific approach involves conducting experiments with populations of organic macromolecules which are combined in a liquid medium, in order to study their self-organizing properties. An example is the artificial evolution of ribonucleic acid molecules (RNA) with specific properties. The research into RNA and similar scientific programs, however, often take place in the areas of biochemistry, molecular biology, and combinatorial chemistry as well as other carbon-based chemistries. Such wetware research does not necessarily have a commitment to a singular idea, often assumed by scientists in software artificial life, that life is a composed of medium-independent forms of existence.

Thus, wetware synthetic life is concerned with the investigation of self-organizing principles in 'real chemistries'. In theoretical biology, autopoiesis is a term for a specific kind of self-preservation produced by networks of components producing their own components and the boundaries of the network in processes that resemble organizationally closed loops. Such systems have been artificially created by chemical components not present in living organisms.

Questions of theology are hardly discussed in synthetic life research, but the very idea of a human researcher 'playing God' by creating his own world for doing experiments (in the computer or the test tube) with the laws of growth, development, and evolution demonstrate that some motivation for scientific research may still be connected to religious similes.