art in science

I had the neat experience yesterday of talking to a class about scientific illustration, from my point of view as a scientist who does a lot of illustrating my own work.

The students' questions ranged widely. Some were very technical -- what tools do I use, why do I hatch in a particular style? Others were more conceptual -- how do artists put flesh onto bones in their reconstructions?

In that light, Carl Zimmer has a nice article in the Science Times today about the work of artist reconstructors of fossils: "Artists Mine Scientific Clues to Paint Intricate Portraits of the Past". I get asked about artist reconstructions every so often -- "How accurate are they? Are they scientific? Are they just made up?"

Zimmer discusses many kinds of fossils, from dinosaurs to humans. For ancient humans, one new aspect is that we have details from their genomes about possible phenotypes, based on associations in living human populations. This came into play for the reconstruction of the "Paleo-Eskimo" individual whose genome was published in Nature last month:

Mr. Godtfredsen’s picture is plausible, rather than photographic. It’s impossible to pick out an individual from a police lineup based on nothing but a genome. Dark hair, brown eyes and a stocky build could describe thousands of people who live in the Arctic today. It’s also important to bear in mind that genes rarely guarantee any particular traits; instead, they tend to be associated with them. So we can’t know for sure that having a so-called baldness gene meant that Inuk actually ended up bald. It’s certainly possible that he died too soon to find out.

Zimmer also discusses Jay Matternes' reconstruction of Ardi:

Mr. Matternes worked for years with the scientists on his reconstruction of Ardipithecus. First he drew its skeleton. Onto the skeleton he added muscles, and finally skin and hair. Mr. Matternes infused the picture with a deep artistic understanding of anatomy. But it is also a scientific hypothesis.

This is the point I try to emphasize -- an artistic reconstruction is a hypothesis. It is communicated visually, unlike hypotheses that are expressed verbally or mathematically. Elements of it are testable -- they can be refuted by making further observations. I was explaining this to my introductory anthropology students yesterday as well -- that Matternes reconstruction of Ardi is a hypothesis about posture and locomotor mode. Looking at the reconstruction helps to frame further tests of that hypothesis in a way that complements the verbal description of the anatomy, although it doesn't supersede or substitute for the anatomical description.

But there is another aspect to the artistic representation of fossils: It conveys the reality of the objects.

I find that these two aspects of artistic representation are in tension.

Clearly communicating about the anatomy of a fossil requires a representation that highlights some anatomical aspects and glosses those that are irrelevant. Having the experience of the reality of an object requires a different kind of representation. On a surface level, for example, one may consider that fossils are broken and discolored in various ways. A true-to-life rendering of the discolorations will accurately convey something about the objects, but may obfuscate the anatomy. The very act of representing a fossil in a way that corrects for breakage and distortion is a kind of reconstruction -- a kind of hypothesis, in other words. It conveys information about the way the artist or scientist conceives of the object's relation to other objects.

Likewise, an artist's fleshed-out reconstruction of a fossil skull communicates the artist's hypothesis about the relation of the skull to ancient flesh and the living flesh that the artist knows through study and observation. It obfuscates some details of the fossil, and highlights others.

All art has this tension. We understand that an artistic representation of a living person is a kind of fiction -- it can never capture the person herself, only some aspect of the person. It may exaggerate some and gloss others.

So it is natural for some viewers to see an artistic representation of a fossil with suspicion. The agency of the artist is apparent, and we may not trust that the artist is an appropriately skeptical observer. When we look at multiple reconstructions of the same fossil, the power of convention is apparent.

Just think -- how many reconstructions of Neandertals have you seen in the last few years that weren't red-headed? Gurche's new one isn't, but almost all have been. The red-headed Neandertal clearly conveys the information about the genomics of MC1R, and yet the color itself is just a hypothesis. As I discussed upon the discovery, even if the variant has the postulated functional effect on melanocortin reception by melanocytes, there may well have been modifier genes that made Neandertal hair blonde. The convention of the red-headed Neandertal follows the needs of museums and textbook authors, all of whom need to tell the story about genetics. But in that sense, it's rather like the convention of a bearded Jesus -- making the Neandertal iconic triggers our recognition, but may subtract the need to scrutinize closely, to experience the form anew.

I have some more to write about this topic, using Jay Matternes' Ardi reconstruction as case study -- so check back later!

UPDATE (2010-03-24): I'm reminded of a post from last year, "Paleo-artists in the spotlight", which pointed to a well-illustrated Michael Balter profile of several artists in Science last July.

Michael Balter writes in this week's Science about the artistic reconstruction of ancient fossil hominins. The occasion for the article seems to be John Gurche's preparations for fleshing out the new Hall of Human Origins at the National Museum of Natural History:

In the morning, Gurche would pack up the heads in crates and drive them to the Smithsonian Institution in Washington, D.C., where they will be displayed next year in the National Museum of Natural History's new Hall of Human Origins. The result, says Richard Potts, head of the Smithsonian's Human Origins Program, will be a chance for museum visitors to "look into the eyes of our ancestors." It will also be another job done for Gurche, one of an elite group of paleoartists (see sidebar, p. 139), who combine cutting-edge research and exquisite artistry to bring hominins back to life in museum displays, magazines, and documentaries.

The article goes through some of the scientific background and artistic choices made in reconstructions. The most interesting to me is to see the way that different contemporary artists choose to represent the same fossils -- Balter's article illustrates Daynès' and Gurche's reconstructions of the Liang Bua 1 hominid as a good example -- the two differ radically in hair, pigmentation, nose form, and attitude. That's a big reason why I think more representations are much better for the science -- if we start to really focus in on one reconstruction, it has the potential to cloud our thinking. Looking at two images of the same fossil really helps to clarify the interpretive effort that goes into them.

A sidebar to the article profiles the training of paleo-artists Gurche, Elizabeth Daynès and Adrie and Alfons Kennis. Want to reconstruct hominins in three dimensions? There seem to be two routes: start with dissections and work your way up, or start with an art background and work your way down.

References:

Balter M. 2009. Bringing hominins back to life. Science 325:136-139. doi:10.1126/science.325_136

On the intersection of science and art, the NY Times profiles former astronaut Alan Bean, who for nearly thirty years has painted what he experienced in spaceflight:

Critical attention has eluded Mr. Bean, 77, though he has developed, largely through word of mouth, a following among private collectors who pay up to $175,000 for one of his works. In July, the Smithsonian Air and Space Museum in Washington will mount a show of 45 of his works and will release a book of reproductions of his paintings. He has high hopes that the 40th anniversary of the moon landing may lure critics to take a look at his work.

I'm used to drawing and painting an entirely different kind of lifeless body. But the Moon poses unique challenges:

“People talk about nature being beautiful, and it is, but it’s not harmonized like a painting,” he said. “If Monet painted what he saw, we wouldn’t celebrate him today. He painted a little of what he saw but then he painted mostly the way he felt about it.”

Yet Mr. Bean’s methods still reflect his scientific side. He builds a scale model of every scene he paints, and uses a klieg light to simulate the sun and to get the shadows right. He works out the angle of the light and the positions of the people with mathematical precision. He wants the details to be historically correct.

The story doesn't cover the artistic side of NASA, and thereby may leave the impression that Bean is more of an anomaly than he really is. An immense attention to scientific illustration accompanied the development of the space program, as photorealistic renderings of space (and very early on, animated computer graphics) were an important part of spreading the science to the public. Bean's approach is, of course, very different and helps to extend the tradition outside the technical aspects into the humanistic sphere.