Nick Wade has a new article in the Times, exploring the problem of photo manipulation in scientific papers. The article quotes the editors of the Journal of Cell Biology extensively.
In some instances, he found, authors would remove bands from a gel, a test for showing what proteins are present in an experiment. Sometimes a row of bands would be duplicated and presented as the controls for a second experiment. Sometimes the background would be cleaned up, with Photoshop's rubber stamp or clone stamp tool, to make it prettier.
Some authors would change the contrast in an image to eliminate traces of a diagnostic stain that showed up in places where there shouldn't be one. Others would take images of cells from different experiments and assemble them as if all were growing on the same plate.
I don't worry too much about Photoshopping illustrations of fossils. Instead I worry about two things.
One is picture selection. It is easy to choose pictures that support your argument and hide pictures that don't. Sometimes these are really obvious, like when two bones are shown side by side in different orientations. When that happens, you just know that something isn't what the paper is saying.
Sometimes problems are less obvious to the viewer, like when lighting from different angles may accentuate or hide a feature. People put a lot of faith in good pictures, but it's pretty easy to hide anatomy with them.
My other worry is all these CT reconstructions. It is pretty common to publish a picture of a reconstruction nowadays. But there is no possibility of evaluating such a reconstruction from a picture.
With a picture of a cast, you can at least sort of see where the plasticine was gooped in. With a computer image of a CT reconstruction, it would be very easy to hide bad joins, overlaps, or ambiguities. Reconstruction is always down to judgment; my concern is that the tools that make it easier also make it easier to fake.
More eyes on these things is the only solution. Are reviewers paying attention?