Anyone who studies biology for long enough realizes that eventually an exception is discovered for almost every "rule". We all learned that one of the things that separates animals from plants, protists and bacteria is that they are heterotrophs - no photosynthesis for bunnies and jellyfish. Except recently researchers have discovered that aphids (those tiny green insects that crawl all over your tomato plants) might be able to do photosythesis. Aphids can synthesize carotenoids (orange pigments), and these aphids made more ATP when placed in light then when they were moved into the dark. Now they have to figure out how the process works.
