length and diameter of their tubesâvery similar to the kinds of metrics he applies to trilobites. When he mapped the evolution of cornets using techniques similar to those he applies to ancient arthropods, he found that the pattern of the lineages were very similar in many ways to those of living organisms. As one example, the evolution of cornets showed a stepwise progress, much like trilobites. But the evolution of musical instruments was also very distinctive. The key difference between the evolution of multicellular life and the evolution of the technium is that in life most blending of traits happens âverticallyâ in time. Innovations are passed from living parents down (vertically) through offspring. In the technium, on the other hand, most blending of traits happens laterally across timeâeven from âextinctâ species and across lineages from nonparents. Eldredge discovered that the pattern of evolution in the technium is not the repeated forking of branches we associate with the tree of life, but rather a spreading, recursive network of pathways that often double back to âdeadâ ideas and resurrect âlostâ traits. Another way of saying the same thing: Early traits (exaptations) anticipate the later lineages that adopt them. These two patterns were distinct enough that Eldridge claims one could use it to identify whether an evolutionary tree depicted a clan of the born or of the made.
Evolutionary Tree of Cornets. The design heritage for each musical instrument shows how some branches borrow from far earlier models or nonadjacent branches (dotted lines), unlike organic evolution.
The second difference between evolution of the technium and evolution of the organic is that incremental transformation is the rule in biology. There are very few revolutionary steps; everything advances via a very long series of tiny steps, each one of which must work for the creature at the time. In contrast, technology can jump ahead, make abrupt leaps, and skip over incremental steps. As Eldredge points out, âNo way did the transistor âevolve fromâ the vacuum tube the way the eyes on one side of a flatfishâs head are derived from the original bilaterally symmetrical conformation of the ancestral fish.â Instead of the hundreds of millions of incremental improvements the flatfish endured, the transistor leaped from the ancestral vacuum tube via dozens of iterations at the most.
But by far the greatest difference between the evolution of the born and the evolution of the made is that species of technology, unlike species in biology, almost never go extinct. A close examination of a supposedly extinct bygone technology almost always shows that somewhere on the planet someone is still producing it. A technique or artifact may be rare in the modern urban world but quite common in the developing rural world. For instance, Burma is full of oxcart technology; basketry is ubiquitous in most of Africa; hand spinning is still thriving in Bolivia. A supposedly dead technology may be enthusiastically embraced by a heritage-based minority in modern society, if only for ritual satisfaction. Consider the traditional ways of the Amish, or modern tribal communities, or fanatical vinyl record collectors. Often old technology is obsolete, that is, it is not very ubiquitous or is second rate, but it still may be in small-time use. For just one of many examples, as late as 1962, in what was then called the atomic age, many small businesses on a block in Boston ran machines using steam power delivered to them by overhead driveshafts. This kind of anachronistic technology is not at all unusual.
A Thousand Years of Helmet Evolution. The American zoologist and medieval armor expert Bashford Dean sketched out this diagramatic âgenealogical treeâ of the evolution of medieval European helmets starting in the year 600.
In my own travels around the world I was struck by how resilient