Via Jessica Palmer, here’s an interesting project: a multimedia essay on ecological mythos, Romanticism and 19th-Century science, filmmaking, and Middle-Earth.
It’s called The Mythoecology of Middle-earth: A report from the Shire, a landscape born of high fantasy, natural science, and geek tourism, by Peter Nowogrodzki, and it’s a virtual cabinet of curiosity (or confection, as Tufte would say) inviting readers to explore connections between natural history, travel, and mythology:
In the century before Tolkien’s birth, the study of nature itself had become the subject of ardent imaginative exploration: The Age of Discovery’s there-and-back conquests uncovered troves of biological data, fodder for the Age of Wonder, in which “Romantic science” strived to imitate poetry—not just describing nature but transforming the world by fundamentally altering our perception of it.
It has birds (eagles, giant: real and mythical), trees (as illustrated by Haeckel, Blake, and the Weta Workshop), meditations on the virtual and the mythology of filmmaking, demands by Maori for respect for indigenous landscapes and by labor unions for better pay.
I’m not sure it has a point, but it creates some interesting juxtapositions.
One version of the tree of life, by Ernst Haeckel (Wikipedia)
The evolutionary “tree of life” is a well-known metaphor for the broad scope and branching pattern of evolution over time. This metaphor was first developed by Charles Darwin in On the Origin of Species, as a way to help shape his ideas about evolution by natural selection.
Darwin used several of different metaphors in Origin, but the tree of life is key in that it presents his central organizing vision of shared descent, the idea that all species are related and ultimately evolved from a common ancestor in the distant past. From a single starting point in this image, genetic changes in different populations send species down different evolutionary paths. Some of these “branches” survive, and split in turn to end off new branches. Other branches wither, and species become extinct. The species we see today are represented on the tree by new budding twigs, and those species that have become extinct are represented by the woody branches.
The idea that all species are related by common descent from a single ancestor is quite a profound difference between Darwin’s ideas about evolution and other ideas about evolution that had come before. This is probably the aspect of his theory that has been resisted the most by the general public. If all life is related by common descent, what does this imply about humanity and our place in the world? In Darwin’s view of nature, humans are an integral part of the natural environment, rather than in a separate, special position. Because Western religious traditions emphasize a separation between humans and the rest of nature, Darwin’s ideas were (and have remained) controversial.
Cartoon of Darwin as an ape-man, with a tree in the background. (Wikipedia)
In fact, Darwin’s metaphor of the tree of life was so influential in his lifetime that caricatures mocking his idea of common descent generally feature a tree somewhere in the image (while the other common motif is Darwin himself pictured as an ape-man).
What type of tree do you picture when you think about the tree of life?
While the tree of life does a good job of illustrating common descent, this metaphor, like all metaphors, has a few limitations. For one, the tree in the metaphor is often depicted as a temperate tree like an oak, with a thick central trunk. This thick, woody trunk doesn’t map well to what we know about early evolution- for example, we now know that there were probably many instances of gene transfer among different groups of organisms early in the history of life. Some biologists have suggested replacing the traditional oak tree with an image of a mangrove, with many interconnected branches and roots near its base, in recognition of this early complexity in the history of life.
While modern research gives insights into the evolutionary history of life that Darwin could only have dreamed of, his broad metaphor of a tree still seems to be going strong. Regardless of its ultimate shape, the tree of life seems poised to remain with us for a long time to come. However, this does not mean that there aren’t alternative ways to picture evolution. Could an alternative metaphor to the tree of life help us make mental connections about evolution in different ways? This is a question I hope to answer in my own research.
References:
Gruber, Howard E. “Darwin’s ‘Tree of Nature’ and Other Images of Wide Scope.” inHoward E. Gruber and Katja Bodeker (eds.) Creativity, Psychology and the History of Science, pp 241-257.New York: Springer, 2005.
Gruber, Howard E. “Ensembles of Metaphors in Creative Scientific Thinking.” inHoward E. Gruber and Katja Bodeker (eds.) Creativity, Psychology and the History of Science, pp 259-270.New York: Springer, 2005.
Larson, Barbara, and Fae Brauer. The Art of Evolution: Darwin, Darwinisms, and Visual Culture. Hanover, NH: Dartmouth CP, 2009.
Stevens, Peter F. “Pattern and Process: Phylogenetic Reconstruction in Botany.” in Henry M. Hoenigswald and Linda F. Weiner (eds.) Biological Metaphor and Cladistic Classification. pp. 155-179. Philadelphia: U of Pennsylvania, 1987.
Metaphor plays a number of roles in the scientific process, from facilitating exploration of newly-recognized phenomena, to grounding predictive models that aid in analysis, to transporting ideas among different scientific fields, and perhaps finally to public communication. When Charles Darwin wrote On the Origin of Species, metaphor had a central role in shaping his ideas about evolution by natural selection. He also was explicit about using metaphor to describe his theory.
Artificial selection apparent in dogs (Ellen Levy Finch).
Darwin used a number of different metaphors in his book for different aspects of his theory. Some of these metaphors took years to develop, and became central organizing ideas of his work. He used others more to ‘translate’ his ideas for the public consciousness. Howard Gruber lists five main metaphors in the Origin: artificial selection, wedges, war, a tree, and a tangled bank. Of these, the tree of life and warfare metaphors seem to be the two that are most widely referenced today.
Darwin used artificial selection– plant and animal breeding- to relate natural selection to a familiar process. In both types of selection, a population of organisms starts with genetic variation. In natural selection, limited resources and competition mean that only some of the organisms will survive to reproduce. In artificial selection, people pick organisms with desired traits to reproduce. This metaphor illustrates that selection can result in large changes in a population over time. One problem with this metaphor is that “selection” implies a “selector,” and natural selection happens largely via chance.
Action of a wedge (Wikipedia).
The wedge metaphor made it into the first edition of the Origin, but Darwin removed it from the second- so most people haven’t seen it. He says: “The face of Nature may be compared to a yielding surface, with ten thousand sharp wedges packed close together and driven inwards with incessant blows, sometimes one wedge being struck, and then another with greater force.” Wedges that stay in the yielding surface are species that survive, but to stick into the surface they presumably have to pop other wedges out.
While the wedge metaphor implies that competition is necessary for survival, the warfare metaphor makes this more explicit. For example, seedlings need to overcome “enemy” seedlings in a competition for space, and males compete for females in sexual selection. Today, the warfare metaphor is largely known by the phrase “survival of the fittest” (which didn’t actually appear in the first edition of Origin).
Darwin’s tree metaphor is probably his central organizing vision of evolution over time. From a single starting point, genetic changes in different populations send species down different evolutionary paths. Some of these “branches” survive, and split in turn to end off new branches. Other branches wither, and species become extinct. Over time, the single starting species gives rise to a multitude of different species, some persisting and some passing away. The metaphor of the “tree of life” is one that Darwin worked on for years and was never entirely satisfied with, but it’s a metaphor that still has a lot of resonance today.
Another "tangled bank": a coral reef (Richard Ling, Wikipedia).
While the tree of life represents the grand scope of evolution over time, the tangled bank illustrates the diversity of life that we can see all around us: “It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us.” He uses the diverse “tangled bank” to illustrate how complexity can arise from the interaction of a few simple rules for natural selection. This is actually the final grand metaphor in the Origin, and in it he tries to provide readers with a vision of life’s diversity, underpinned by the common relationships of species.
References:
Darwin, Charles, and James T. Costa. The Annotated Origin: A Facsimile of the First Edition of On the Origin of Species. Cambridge, MA: Harvard, 2009. Print.
Gruber, Howard E. “Diverse Relations Between Psychology and Evolutionary Thought.” inHoward E. Gruber and Katja Bodeker (eds.) Creativity, Psychology and the History of Science, pp 167-191.New York: Springer, 2005. Print.
As part of my dissertation, I’ve been looking at several metaphors that Charles Darwin used to describe evolution and natural selection in The Origin of Species. It’s been interesting to see which have survived to the present day and which haven’t: Darwin was a great popularizer of his own ideas, but some of his images have stayed in the public eye more prominently than others. The ‘big one’ is probably the metaphor of the “Tree of Life” as a metaphor for evolution in its entirety, but there are several others that he used to illustrate different aspects of his theory. But I’m planning on writing more about this later…
Today, I wanted to point to this discussion, held at the Grant Museum of Zoology of the University College London, on the question of whether Darwin would have been able to get a job as a biologist today. On the surface, it’s a ridiculous question: Darwin’s body of work was the impetus for one of the most profound transformations of the field of biology that has ever occurred. His work has had an incredible impact on the way we view ourselves as a species in relation to the rest of life (and also has been misappropriated in an attempt to justify some strikingly heinous social policies). But if you dig a bit deeper into the kind of scientist he was, and the way that science as a discipline has changed, this actually is an interesting question.
Darwin in his early 30's. No, he didn't always have that famous beard. (Wikipedia)
In a nutshell, Darwin was a ‘gentleman scientist,’ naturalist, and experimentalist, who spent a lot of time observing many different aspects of the natural world. While he’s famous for observing some birds on a long ocean voyage, he also wrote about volcanoes, fossils, coral reefs, plants, chicken breeding, and compost. Today, molecular biology and lab work are where much of the biology action is, and basic natural history research is seriously underfunded in many places. There’s also a much higher degree of specialization among scientists today. So, would Darwin have been able to compete in today’s environment? Take a look at what the museum’s panelists had to say.
My guess is that he would be able to make it in biology today- he seems to have been a pretty adaptable individual, social networker, and fundraiser. But would miss the hands-on excitement of collecting new species of insects, examining rocks, and poking around on tropical islands? I’ll bet he would.
