Jorge Wagensberg
Physicist

For thousands of years, bacteria were the only living creatures that swam about the planet. Consequently, something remarkable must have happened during the timespan between these early bacteria and Mozart, for example. Various innovations have taken place, one after the other, though the most important have an essential detail in common: in some way they signify the emergence of a centre, a co-ordination centre, a control centre, a concentration of some kind of intelligence. The first major event was undoubtedly the development of the cellular nucleus of eukaryotic cells, a distinctive place where almost the entire life is managed of cells that have to serve as veritable building blocks for animals and plants. While living beings drifted or allowed themselves to be carried by currents, not much more was required. But when food began to run short, then the need arose to invent mobility, willed and directed movement; if food does not spontaneously crash into a living being, then that living being must go off in search of it. This requires additional and hitherto unseen features. Isotropy (all directions are equal) favours forms that are circularly symmetrical (jellyfish, sea urchins, sponges and the like), but movement breaks the isotropy because the direction of the movement is very special and so forms of bilateral symmetry in relation to an axis perpendicular to the movement developed (all animals that move display this: fish, arthropods, reptiles, birds, mammals, etc.). But there is more. Movement requires you to perceive and interpret the surroundings, make decisions, orientate yourself and so on. In other words, information must be processed. Nerve cells were first concentrated in ganglia and then gradually gave rise to a large co-ordination and control centre, the brain. Animals that do not move do not have a brain because they have no need of one. The brain was invented in order to leave home (and memory in order to return home). We now have multicellular animals with the ability to move and to process information. In general, however, they were either too soft, and hence vulnerable to predators, or they were heavily armoured and so weighed too much to be able to move agilely. Another major event was therefore called for, another great innovation,
another tremendous discovery in the history of the evolution of life. How would it be possible to do away with the external armour? How could the entire structure of the body be supported? How could such a structure be made flexible, strong, stable and safe in response to any movement, need or emergency? How could the system be made to adapt conveniently and automatically to the living individual’s growth? The solution is unique. It seems unique. Fish invented it and all vertebrates should be grateful to them for their existence and viability: it is graceful, pliable, durable, flexible, powerful, taut, adaptable, modular, ingenious, hardwearing, unrepeatable, sensible, well connected and wired, full of outlets, inlets and bifurcations, an excellent distributor of everything, of loads, signals, braces and flows. Fish, reptiles, amphibians, birds and mammals have it: it is the backbone, one of the three or four major developments on the path towards humankind.

In the sculpture entitled Organic Shadow, the artist Enric Pladevall has captured that crucial instant in the history of the cosmos with each and all of its nuances. The backbone has, then, been invented twice. Once by nature and the second time by the artist.