Elena Renken in Quanta:
Two years ago, to prepare for an unusual photo shoot, a team of scientists plucked the wings from thousands of fruit flies and pressed each flake of iridescent tissue between glass plates. As often as not, the wing tore or folded, or an air pocket or errant piece of dust got trapped along with it, ruining the sample. Fly wings are “not like Saran wrap,” said Madhav Mani, an applied mathematician and engineer at Northwestern University who led the project. They’re fragile, he said, “like gold leaf foil.”
Persevering until they had perfectly mounted about 2,000 pairs, the scientists then photographed the wings in high resolution and systematically compared the photos in 30,000 places.
This was no mere exercise in taxonomy. Rather, the study, which was recently published in the journal eLife, has offered an exceptionally detailed look at the variation that can exist within a species. The results begin to resolve a long-standing tension in biology.