The Evolution of Evo-Devo Biology
Developmental biology (‘devo’) and evolutionary studies (‘evo’), once seen as distinct, yet complementary disciplines, have recently merged into an exciting and fruitful relationship. The official union occurred in 1999 when evolutionary developmental biology, or “evo-devo,” was granted its own division in the Society for Integrative and Comparative Biology (SICB).
It was natural for evolutionary biologists and developmental biologists to find common ground. Evolutionary biologists seek to understand how organisms evolve and change their shape and form. The roots of these changes are found in the developmental mechanisms that control body shape and form. Developmental biologists try to understand how alterations in gene expression and function lead to changes in body shape and pattern. So although SICB only recently validated evo-devo as an independent research area, evo-devo really started over a decade ago when biologists began using an individual organism’s developmental gene expression patterns to explain how groups of organisms evolved.
To highlight this emerging field, the Proceedings of the National Academy of Sciences (PNAS) Editorial Board has sponsored a special feature on Evolutionary Developmental Biology. This evo-devo special feature contains eight Perspective articles and a review that examine evo-devo’s progress to date, as well as 15 research articles that add new information and focus on the most recent evo-devo biology trends. The majority of the research articles were submitted directly to the PNAS office through the Track II system, and were evaluated by an Editorial Board member. After the initial screening, papers were assigned to an Academy Member-editor who oversaw a process where research manuscripts were rigorously peer-reviewed by experts in the field.
Biologist Donald Ingber explains how tensegrity helps to understand the origins of life in a 2007 conversation with Sputnik Observatory:
There’s beautiful work from 1917. D’Arcy Thompson had a book where he had a picture of one fish or one face of one ethnic group on a grid. Then they deformed the grid. They pull it this way, they pull it this way, they stretch it that way, and you get all the different species from that form. It’s not saying they we’re physically deformed in that way, but it’s basically saying that physical alterations of the structure are how you get different forms. They could be from internal forces, the cells pulling differently in this area than that, or it could be in a different physical environment, adapting. And the reason that I thought tensegrity really helps to understand origin of life is that each time you go through a systems jump where you put many elements together, whether they’re molecules or cells or tissues, you now have something that when the environment changes, for example it gets very cold or if it gets very salty and you change the structure, most things might break and you lose them but tensegrity is resilient so it can change when it freezes and then come right back again. Those would be selected. Without genes there would be natural selection, environmental selection by physicality, by stability. I think that’s something that’s interesting because most people who work on evolution only think about DNA and RNA and selection by genetic selection. Basically, we’ve had geodesic forms in the inorganic world for millions of years before we had life. We see it in cells, we see it in subcellular components, we see it in our bodies. So that means that the same rules must have been driving evolution in the inorganic world before life and DNA came about.
Michael Hensel, architect, discusses the notion of ‘morpho-ecology’ and how we need to understand the process of formation:
The title Morpho-Ecology brings, in principle, two or three notions or concepts together. On the one hand, morphology or morphogenesis; on the other hand, ecology. This is basically saying that in the morphological part we’re looking at the material constituent, and in the ecological part we’re looking at how this is embedded in a given environment. The term “morphology” was originally coined by Goethe in his studies on botanics, and he basically stated that when we look at nature we cannot concern ourselves merely with gestalt, with shape. Because everything that acquires a shape immediately, in the next moment, changes it’s shape. And he was arguing through the growth of a plant that any time you try to describe a shape it’s only a snapshot in time, because the next day it’s bigger and distributed in a different way. So material is redistributed all the time. It’s a constant process of formation. So what he states is that, up to that point, maybe plant shape studies were merely focused on drawing these snapshots. And he said we need to understand something other than that – we need to understand the process of formation. What is driving plants to grow into a particular shape and into a next shape and next shape? He basically says once something has acquired a shape, it immediately transforms into another. So morphology in that sense, or morphogenesis, the way form comes into being, is a dynamic process. And this dynamic process can only be understood in relation to the environment with which the organism that develops is in contact.
So what we call “morpho-ecology” is probably unnecessary for a biologist, because a biologist would always understand that every organism unfolds and becomes a kind of individual material expression in permanent exchange with the environment. But architects don’t. First of all, because we build our buildings for long time spans. And we don’t think of a building as something that in and of itself will change unless it’s mechanically done. An example would be, for instance, the Schroder House by Rietveld where you have panels that you move around and you change the interior configuration of the house or, for instance, the facade for the Institute for the Arab World by Jean Nouvel which has camera-like apertures that close and open in relation to the sunlight. But this is, again, all mechanically enhanced. So the question is really how can we begin to think of buildings not just as temporary storages of material but also as something that is somehow, in someway, in exchange with the environment and that might also be affected by the environment, while in turn affecting the environment.