Morphogenesis

Art and biology can be a natural fit. Some artists explore Artificial Life (Alife art). But morphogenetic art is a least known trend, interested in geometric structures derived from the observation of nature. Both approaches have common roots, but also great methodological and epistemological differences. A more precise definition of morphogenetic art will help understand how biology can provide strategies for creation.

Author(s)

Defining Morphogenetic Art

Generative art inspired by natural patterns and growth mechanisms can be named “morphogenetic art.” To better define morphogenetic art as a blend of art, geometry and biology, we must first describe what is morphogenesis, a subfield of biology closely related to Artificial Life (Alife).

Morphogenesis and Geometry

Morphogenesis is “the ensemble of mechanisms underlying the reproducible formation of patterns and structures and controlling their shape.” [1] As a subfield of biology, it refers mainly to growth patterns in living organisms. Elegant equations can describe patterns as diverse as crystal configurations, spots on a fur, the texture of a horn or the arrangement of leaves on a stem. For example, the Fibonacci sequence, related to the golden ratio, named after an Italian mathematician of the 12th century but already known from the Indian mathematicians since the 6th century, is used to describe spirals found in nature, like from the unfolding of a fern, the arrangement of seeds and petals, etc. 

Geometry helps to find the common roots of seemingly unrelated manifestations. For example, an ellipse can be defined by an equation. A mathematician called Lamé, in the 19th century, generalized this equation to describe an ellipse, a circle and a rectangle at once. This equation called “superellipse” was further generalized by Gielis, extending it for example to radial symmetry. This “superformula,” published in 2003, [2] encompasses a lot of different natural forms from fruits and flowers to butterflies. Other equations such as spherical harmonics, minimal surfaces and reaction-diffusion systems are used in fields as diverse as atomic physics, geology, fluid mechanics, botany and chemistry.

Classical morphogenesis mainly tries to grasp the principles behind pattern formation and not the actual mechanisms of growth, that can be very complex and hard to modelize. For example, a few dozens of models can be found in the literature to explain the same arrangement of leaves on a plant stem, the main study of a field called “phyllotaxis.” But some dynamic processes are more easy to formalize than others, giving some clues to help find the actual mechanisms that could be involved in the formation of certain patterns. Morphogenesis is therefore working on a purely geometric level only to describe forms and formation patterns, regardless of the causes governing the generation of these patterns in nature. In the words of René Thom, one of the great thinkers of morphogenesis:

“That we can construct an abstract, purely geometrical theory of morphogenesis, independent of the substrate of forms and the nature of the forces that create them, might seem difficult to believe, especially for the seasoned experimentalist used to working with living matter and always struggling with an elusive reality. This idea is not new and can be found almost explicitly in D’Arcy Thompson classical book On Growth and Form[...].” [3]

D'Arcy Thompson, with his book On growth and form, [4] is often considered as the father of morphogenesis. But the term is already used in a fundamental book by Leduc, from 1912, called La biologie synthétique. We will see that his experiments in generation of forms illustrate the common roots between morphogenesis and Alife.

Synthetic Biology and Artificial life

The fundamental experiments of Leduc [5] showed that shapes, patterns and behaviours previously associated with life can appear as a result of complex physico-chemical conditions. He generated fascinating moving and evolving organic shapes with drops of ink in metallic salts and alkaline silicates medium showing “the molecular forces brought into play by solutions, osmosis, diffusion, cohesion, and crystallization.” These artificial creatures were looking like “flowers and seed-capsules,” “most remarkable fungus-like forms,” “capsules or closed shells,” “amoeba,” “a free swimming organism, a transparent bell-like form with an undulating fringe, like a medusa.” These artifical creatures illustrated an approach in the study of life called “synthetic biology.” 

Other leading scientists contributed to this approach. Turing, forty years later in his seminal paper on morphogenesis by reaction-diffusion, suggested that “a system of chemical substances, called morphogens, reacting together and diffusing through a tissue, is adequate to account for the main phenomena of morphogenesis.” [6] Leduc and Turing shared the same idea: if some fundamental patterns, shapes and behaviours can be synthesized by physico-chemical reactions on inorganic elements, life could have emerged from the organization of matter. We find an echo of this idea in the foundation of Artificial Life. As Langton, an important founder of the field, describes it: “Artificial Life (AL) is a relatively new field employing a synthetic approach to the study of life-as-it-could-be. It views life as a property of the organization of matter, rather than a property of the matter which is so organized.” [7] Life is thus an emergent property of matter.

Morphogenesis avoids debates between mechanistic and vitalistic and other fundamental positions about what life really is. But it shares with Alife and with synthetic biology the idea that characteristics of life can often appear in the field of the non-living. Picking only one example, a dune of sand forms a complex system where grains of sand are driven by the wind but are also altering the dynamics of the wind. [1] The typical morphology of an isolated dune takes under constant wind is called a “barchan,” It's a crescent shape sand ridge with the two horns pointing downwind, with the upwind side at 15 degree and the downwind slope (called “slip face”) at 35 degrees. This precise configuration is invariant with size, moves at a defined speed under favorable conditions without loosing its shape, can “die” if deprived from new sand carried by the wind, and can even reproduce by splitting in two little barchans while colliding and fusing with another barchan! Self-organization, dependance to external conditions and supply, constance of the shape, birth, death, predation, motion, reproduction, collective behaviour, are all characteristics of life that have their manifestations in the inorganic world. Like Leduc says: “All the supposed attributes of life are found also outside living organisms. Life is constituted by the association of physico-chemical phenomena, their harmonious grouping and succession. Harmony is a condition of life.”

Another shared observation is that simple principles can produce complex manifestations. One example is cellular automaton. For example, in the well-known implementation from Conway called “Game of life,” [8] the environment is a grid composed of cells that can be in one of two states: alive or dead, represented by a black or a white cell. Simple rules guide each individual cells. At each step, each cell counts its number of neighbours and follows three rules: 1) a living cell will die by loneliness if surrounded by less than two neighbours and by overcrowding if surrounded by more than three. 2) A living cell will survive if surrounded by two or three neighbours. 3) A dead cell will come alive if surrounded by three neighbours. These three simple rules give rise to a lot of different patterns, like stable periodic forms with evocative names as “sparkers,” “guns,” “spaceships,” “puffers” and complicated combinations like “glider-to-spaceship converters.” Cellular automaton mechanisms have been recognised among other morphogenetic processes in the colored patterns of sea shells, in urban growth models and chemical systems.

Definition

This definition of morphogenesis can now be used to better understand what morphogenetic art is.

Morphogenetic art is a subfield of generative arts interested in the dynamics of pattern formation as deduced from nature. Generative art has been defined as “any art practice where the artist creates a process, such as a set of natural language rules, a computer program, a machine, or other mechanism, which is then set to motion with some degree of autonomy contributing to or resulting in a complete work of art.” [9]

It is distinguished from Alife art that try to simulate or to generate life. The pattern formation mechanisms, once formalized in equations and algorithms, can also be used to simulate organic shapes like in what is called “soft Alife,” the study of simulated life. But the artist interested in morphogenesis will be less inclined to imitate the living than to directly present the geometric principle itself. The beauty of an equation lies in its elegance, its simplicity and its universality. It does not capture the beauty of nature but the beauty of the principles that manifest themselves in nature's amazing diversity. Morphogenetic arts don't talk about nature, but about its structure, about the intimate links between nature and geometry.

Designers and architects use the term “digital morphogenesis” to describe the use of shape generation strategies analogous to what can be found in nature. Hensel proposes to bring the analogy between architecture and living systems further, seeing architecture as a living organism, taking into account its growth mechanisms, its behaviours, its adaptability, etc. [10] Artists and scientists of morphogenesis are not only interested in how living systems are organized and how they evolve in their internal structure, but also in their relationship to their environment. Of particular interest for the artist is the way biological metaphors can help consider an artwork in its ecosystem, as a living creature evolving in a particular context, for example social, aesthetic and relational.

For example, looking at the cultural context of generative arts, we can question how we interact with digital artwork. A public immersed in video games, music visualizations and movie special effects can easily confound an artificial life form with some manifestation of popular entertainment. Some interesting generative work blur the boundaries between entertainment and art, virtuality and reality, “life-as-it-could-be” and “life-as-it-is.” But some less mature work seems in need to impress, make the public move, manipulate, interact for the sake of interacting. Morphogenesis suggests more organic strategies to involve the public. For example, when it comes to “interaction,” one proposition is to think of it as “interrelation.”

Personal Experiments

We spent two years developing a series of experiments to refine the concept of interrelation in morphogenetic artworks. The first work of the series presented the non-interactive evolution of a spherical harmonics shape exhibited at the Saussignac castle in Dordogne (http://bit.ly/spherical_harmonics), immediately followed by a second experiment, in an art production residency in Quebec (http://bit.ly/spherical_product), to explore interrelation strategies. A supershape was evolving according to the ambient sound analysis from two different art centers, that collaborated in equal parts to shape the organic form. The result was interactive in the sense that one could see the effect of his or her voice on the evolution of the shape. But, as it was also guided by the ambient sound of the other gallery, the organic form seemed to have a life of its own. The interrelation between the sound and the shape began to feel more abstract than a mere direct reaction. To dig further in this abstract encoding scheme, we developed “Orbs” (http://bit.ly/expo_orbs) and experimented with minimal interaction. The simple throw of a marble in a bowl triggered the deployment of a complex spherical universe. The reciprocating component of the trajectory of the marble was transformed into two circular shapes assembled by spherical product and embedded in an evolving representation of a spherical universe. The minimal but primordial gesture of throwing the marble could barely be assimilated to interactivity, being more like an impulse for the series of geometric transformations, analogous to a minimal interface to the outside world triggering and guiding the growth of an organic shape. In a third experiment called “Genoma,” launched in Italy (http://bit.ly/genoma_mercato) and developed in São Paulo (http://bit.ly/genoma_sao_paulo), the series of geometric transformations was replaced by a complex “genome” encoding. The goal was to explore the possibilities of mapping the ambient sound of the gallery in a way that could not be confused with a direct interaction, but still showing the effect of the sound on the evolution of the shape. The sound analysed acted as a parasite for a rudimentary “genome” made of flocking agents exchanging data as they met. This data mutation influenced the evolution of the shape, involving a luminous Superformula surrounded by a particle system representing the genome flocking in spherical space. The result exhibited very organic behaviours, being autonomous in its development but responding to input from the environment in a very slow and deeply abstract manner. 

This abstract interrelation replacing direct interaction is analogous to the kind of communication we can have with natural phenomena. Gesticulating and yelling at a flower will probably not result in a direct reaction. But caring and watering it will surely determine its evolution. Choosing interrelation over interaction has a profound impact on all kind of relations, be they social or cultural, where the effects often reaches deeper levels as the interaction is subtle.

The next exhibition in preparation also explores the abstract encoding between a stimulus and a generated shape. But this time, the focus is on more advanced geometry. It involves supershapes transformed into catenoids, the Superformula being used as the energy minimization function of a Wulff shape equation to form a “Constant Anisotropic Mean Curvature” (CAMC)[12], a type of minimal surface that can be interesting to morphogenesis. The resulting shapes will be printed in 3D by rapid prototyping and displayed with the word that served as the material for its evolution. Families of shapes evolve following families of sound characteristics, not because they are visualization of the sound, but because the sound is the seed, the impulse that triggers its evolution. In all of these projects, the idea was to experiment with abstract organic mapping as an alternative to the arbitrary mapping that is often used in biologically inspired art works. Instead of aggressive interaction, a minimal interface with the environment and a slow interrelation helped to place the participant in the role of a natural agent influencing, but not completely determining, the becoming of an autonomous shape. 

Conclusion

The study of morphogenesis includes geometric patterns and mechanisms of growth observed in nature. It is a very broad area of research focused on the discovery of the structure of life itself. The combination of Alife, biology, geometry and art can lead to new ways of thinking about natural forms, about the principles at the roots of matter and life, and about the complex interrelations between each part of the complex ecosystem in which we live.

References and Notes: 
  1. P. Bourgine and A. Lesne, Morphogenesis: Origins of Patterns and Shapes (New York: Springer, 2010).
  2. J. Gielis, “A generic Geometric Transformation that Unifies a Wide Range of Natural and Abstract Shapes,” in American Journal of Botany 90, no. 3 (2003): 333.
  3. R. Thom, Structural Stability and Morphogenesis (New York: Perseus Books, 1994), 8.
  4. D. Thompson, On Growth and Form (Cambridge University Press, 1942).
  5. S. Leduc, The Mechanism of Life (London: Rebman, 1914).
  6. A. Turing, “The Chemical Basis of Morphogenesis,” in Philosophical Transactions of the Royal Society of London: Series B, Biological Sciences 237, no. 641 (1952): 37.
  7. C. Langton, Artificial Life: the Proceedings of an Interdisciplinary Workshop on the Synthesis and Simulation of Living Systems (Boston, MA: Addison-Wesley, 1989), 2.
  8. J. Conway, “The Game of Life,” in Scientific American 223, no. 4 (1970): 4.
  9. P. Galanter, “What is Generative Art? Complexity Theory as a Context for Art Theory” (paper presented at GA2003 - 6th Generative Art Conference, Milan, 2003).
  10. M. Koiso and B. Palmer, “Equilibria for Anisotropic Surface Energies and the Gielis Formula,” in Forma 23, no.1 (2008).