What is artificial life?
*Artificiallife as defined by Christopher Langton*
“Artificial Life is the study of human-made systems that exhibit behaviors characteristic of natural living systems. It complements the traditional biological sciences concerned with the analysis of living organisms by attempting to synthesize life-like behaviors within computers and other artificial media. By extending the empirical foundation upon which biology is based beyond the carbon-chain life that has evolved on Earth, Artificial Life can contribute to theoretical biology by locating life-as-we-know-it within the larger picture of life-as-it-could-be. – (Langton, 1989)”
Artificial life (also known as ‘ALife’)is an interdisciplinary study of life and life-like processes that uses asynthetic methodology, wherein researchers examine systems related to naturallife, its processes, and its evolution, through the use of simulations withcomputer models, robotics, and biochemistry.
Three broad and intertwining branches of artificial life correspond to three different synthetic methods.
- ‘Soft’ artificial life creates simulations or other purely digital constructions that exhibit life-like behavior.
- ‘Hard’ artificial life produces hardware implementations of life-like systems and
- ‘Wet’ artificial life} synthesizes living systems out of biochemical substances.
A-life research efforts are genuinely interdisciplinary and run the gamut from biology, chemistry, and physics to computer science and engineering. While a large part of Artificial Life is devoted to understanding life as we know it – that is, life on earth – a significant effort concerns the search for principles of living systems which are independent of a particular substrate. Thus, Artificial Life also considers life “as it could be,” exploring artificial alternatives to carbon-based chemistry.
At present, this subfield is split into two largely independent endeavors:
- Creation of life using the classical building blocks of nature (carbon-based life):Explores the possibility of “RNA worlds” by attempting to construct self-replicating molecules
- Creation of life using the same principles but a different medium for implementation:By simulating simple populations of self-replicating entities, examines the abilities and characteristics of different chemistry in supporting life-like behavior.
Thus, both the biochemical and the computational approaches seek to shed light on the compelling question of the origin of life.
Examples of Artificial life:
**Artificial cells: **Artificial cells aremicroscopic, autonomously self-organizing and self-replicating physicalentities that assemble themselves out of non-living materials. Althoughartificial, they would repair themselves and adapt in an open-ended fashion, sofor all intents and purposes, they wouldbe alive.
The artificialcell would help us understand the origin of life, how can life arise from nonliving substrates along with a clear view of their evolutionary potential. Thekey properties that will help achieve theALife goal are self-maintenance, autonomous control of chemical processing,autonomous control of mobility, and self-replication.
An artificial cell which is simpler than any existing would help instudying the core functions of life, and allow us to work out the function ofevery gene that keeps it alive. That could yield insights into how genes can bere-purposed. It may provide an understandinghow a living cell works. More precisely it may help us unravel the essentialtoolkit of life, something that may be common to all free-living creatures onEarth, including humans.
ALife Research is pursuing two approaches.
- Venter and Smith are using the top-down strategy of artificially synthesizing and modifying the genome of the organism with the smallest genome, the bacterium Mycoplasma genitalium. The other approach is bottom-up, building more and more complicated physiochemical systems thatincreasingly incorporate life-like properties.*In May 2010, a team of scientists led by Venter became the first to successfully create what was described as“synthetic life.” This was done by synthesizing a very long DNA molecule containing an entire bacterium genome, and introducing this into another cell, analogous to the accomplishment of Eckard Wimmer’s group, who synthesized and ligated an RNA virus genome and “booted” it in the cell lysate. *Scientists Create First Synthetic Cell – WSJInteresting there is a lot the step with no doubt would be the corner-stone in the field, but has drawn many opposing the step as well. Wondering why?Easy *“you create the life you become a god,” but are they life? Yes they are but we did not make them up from scratch, scientist has taken such steps in past like cloning and we end up with same question(being ethical is important, but we like to explore) *and next question was important for me *what if we could contain and control such life, we human try to make things better always what is the Alife turn more advanced than us (feeling insecure,sounds like Sci-fi movie right)? These are challenges of innovation it comes with the packages. *An interesting article ready on this can be found here:Ethics concern over syntheticcell – BBC News – BBC.com.
- Some bottom-up efforts are strongly inspired by the RNA chemistry in existing cells, whereas others pursue a simpler chemistry that replaces RNA with PNA(peptide nucleic acid, an analog of DNA in which the backbone is a pseudopeptide rather than sugar).
**Evolutionary Robotics : **
Artificial Life is not only about theconstruction and simulation of living systems, whether artificial or natural;an impressive engineering effort is gearedtowards the construction of adaptive autonomous robots. This work differs fromthe classical robotics approach, in that the robotic agent interacts with itsenvironment and learns from this interaction, leading to emergent roboticbehavior. The ALife alternative is to follow nature and use an evolutionarydesign method.
Evolutionary robotics aims to examinedifferent aspects of applied evolutionary algorithms, including Adaptive andsocial behavior, morphology, control,perception and even self-* (self-adapting, self-assembling, self-repairing, etc). These aspects are responsible for thegeneration of order in nature. They involve components at different scales,such as molecules, cells, and organisms.
Researcher across many disciplinesbelieve that the study of physical models of even self, morphology, control and perception can help in understandingnature and advancing technology. Evolutionary robotics investigates life as “itcould be.” It uses computer simulation tostudy even self as a means by which intelligent compositeentities form and exhibit properties of living beings such as growth,development, self-repair, reproduction. The entities would ultimately changethrough an evolutionary process and hence could be considered as novel forms ofartificial life.
Much work at the multicellular level hasoccurred in ‘hard’ artificial life, which is concerned with various forms ofautonomous agents such as robots. This isartificial life’s most direct overlap with cognitive science, as it aims to synthesize autonomous adaptive andintelligent behavior in the real world. One of the tricks is to allow thephysical environment to generate thebehavior as far as possible. Traditional rational design for intelligentautonomous agents is challenging becauseit involves sophisticated interconnections among many complex components.
There ismany more example domain in artificial life-like the field of Evolutionarycomputing and swarms intelligence(Ant colony optimization, particle swarm optimization, genetic algorithm,etc.), but I would like to discuss themfor later. The two examples above are two sidesof the same coin trying to do the same things in two different approaches to Alife, as described earlier.
The interesting question is *what would we gain by stimulating life or creating an Alife?*, here is what I understood and I think:
- Unravel the essential toolkit of “life-as-we-know-it”– that is, life on earth (carbon chain form of life) and living systems which are independent of a particular substrate -that is “life-as-it-could-be.”
- Artificial Life is often described as attempting to understand high-level behaviorfrom low-level rules. For example, how the simple rules of Darwinian evolutionlead to the high-level structure or the way in which the simple interactions between ants and theirenvironment lead to complex trail-following behavior.
- Study of how evolution and neural networkscan produce artificial brains capable of learning.
- How genetic information is expressed phenotypically, that is, whichamino acids are produced, and evolutionof the genetic code takes the form of changes in the enzymes used in amino-acidsynthesis.
- How does an intelligent composite entityform and exhibits properties of living beings such as growth, development,self-repair, reproduction, social behavior, morphology, control, perception andeven self-* (self-adapting, self-assembling, self-repairing, etc.
- How does a multi-cellular organizationevolves, from simple to more complex as seen in nature?
- Understand aspects of language, includingphonetics and phonology, language acquisition, language change, the evolutionof signaling systems, the grounding of symbols and the evolution of meanings,the emergence of complexly structuredlanguages, and the co-evolution of languages and language learning mechanisms.
- Understand the social and adaptive behaviors of the organism in groups how the structure and behavior of social groups arises and is controlled.
- Understand the natures way of exhibiting a variety of competitive and cooperative ecological relationships.
- Explain how robust, multiple-level dynamical hierarchies emerge solely from the interactions of elements at the lowest level. Understanding this relationship in particular systems promises to provide novel solutions to complex real-world problems, such as disease prevention, stock-market prediction, and data-mining on the Internet.
- Even may help us understand the deep connections between consciousness, emotion, mind, and brain.
In the upcoming post, I would like to discuss the challenges of Artificial life; I am always open to suggestion so if you have one you are most welcomed.
Reference: Bedau, Mark A. “Artificial life: organization,adaptation, and complexity from thebottom up.” Trends in cognitive sciences 7.11 (2003): 505-512.
Thanks to Dr. Alice ‘O Toole for selection of an exciting topic and guidance, my friends and classmatesfor the discussion on the topic which enabled meto dive deep into.