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Artwork is available
Flowering of Vision
Watercolor (green circle: Photoshop)
24 x 30 inches
2001
"Modern" eyes first appeared about 550 million years ago, having evolved through random mutations and natural selection from simple light-sensitive patches on the skin. Researchers at Lund University have calculated that the development of the camera-like eye from a light-sensitive patch might require roughly 1,829 steps (each involving no more than one percent change) and only 364,000 years. This is so fast that eyes could have evolved 1,500 times.
Different eye types have emerged, but, generally, the process probably involved changes in the patch that created a depression, which deepened into a pit capable of sharpening sight that eventually narrowed, allowing light to enter through a pin-hole like aperture. With time, a layer of cells and pigment lined the back (retina), transparent tissue lined the front (lens), and liquids provided a curvature.
Image to the right identifies the eyes portrayed.
* A Pessimistic Estimate of the Time Required for an Eye to Evolve Nilsson, Dan-E.; Pelger, Susanne. Proceedings: Biological Sciences, Volume 256, Issue 1345, pp. 53-58.
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Lesser Kestrel and the Bombing of Baghdad
watercolor
24 x 30 inches
2003
Lesser Kestrels are falcons that breed in the Mediterranean region east to China. Populations have been in decline for some time, commonly in response to pesticide use. These gregarious birds often breed in close proximity to people. Pairs do not build a nest, but lay their eggs on the ledge of tall buildings, old walls, or cliffs.
In the spring of 2003, bombing began in Baghdad. So did the breeding season for Lesser Kestrels. The adult Lesser Kestrel shown here may have survived, but one of its nestlings was lost. Whether the other two would have survived is not clear as subsequent blasts may have further damaged the structure until, as in Jericho, the walls tumbled down.
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Discovering Digitalis
Black-chinned Hummingbird and Foxglove
Pencil, 10 x 15 inches
2010
As if taking a cue from nature, where Black-chinned Hummingbirds (Archilochus alexndri), sample Foxglove (Digitalis purpurea), a mass spectrometer, this one a Micromass LCT with its iconic hummer design, samples the cardiac glycosides in Foxglove. Even the ancient Egyptians used cardiac glycosides medicinally, and understood their narrow therapeutic ratio (the small step from affective dose to one that could kill the patient). Here you see a portion of the Ebers Papyrus, written around 1550 BC, which lists hundreds of remedies, including cardiac glycosides.
You also see a pocket Withering Botanical Microscope, designed for fieldwork. William Withering, a physician, extracted digitalis from Foxglove to treat dropsy (cardiac edema), and in 1875 wrote a monograph on Foxglove and some of its medical uses. Digital is still used in the treatment of congestive heart failure, and some cardiac arrhythmias. For the last five months at Alliance Analytical, a San Francisco Bay Area start-up that strives to keep sound--but no longer used--lab equipment in service and out of the landfill, I've had the opportunity to examine a broad array of instruments used in the pharmaceutical industry. In the process, I've gained an ever greater appreciation for the role of plants, AND instruments in the long and complex process of developing cures. It has been reported, for example, that a total of 26 plant-based drugs were approved from 2000 to 2006, and the global market for plant-derived drugs is projected to reach more than $26 billion next year.
I wonder what effect, if any, the glycosides in Foxglove nectar have on the hummingbirds and whether “nectar-sampling” species might lead us to promising sources of future plant-derived drugs.
Blue Tits, Selection, Social Learning, and Cultural Evolution
(Cyanistes caeruleus)
Pencil, Colored Charcoal, Pen and Ink on Vellum, Photoshop by Darryl Wheye
8 x 11 inches
2012
Blue Tit crown feathers reflect ultraviolet light. What does this signal? To find out, experimenters dulled the crowns of females tending nestlings with an oily compound. Males continued to guard the nest, but reduced their food-bearing trips. Apparently, females maintain attractiveness (and keep mates returning to the nest) through preening that retains the blue luster often muted by dust, pollution and parasites.
Interestingly, when delivering bottled milk to households was the norm, a number of Blue Tits began piercing the shiny foil cap and sipping. The behavior was picked up by other Blue Tits and spread from the U.K. throughout Europe. Attraction to UV and shiny foil suggests sexual selection on the one hand and social learning that might have led to cultural evolution on the other.
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