Ancient autophagy.

These days, when we talk about the origin of a protein, or even a pathway, we are typically referring to evolutionary lineages based on nucleotide sequences. For example, is a particular protein's function conserved? How far back did it first appear? Are there homologs in higher eukaryotes? However, a simpler question (or perhaps I should say, a non-molecular biology question) is when was the process first detected in the paleontological record? Of course I assumed that macroautophagy was ancient, but a new finding (see p. 632 in this issue of the journal) provides an unexpected--and exciting--piece of information for our field. For the first time, scientists have discovered fossil evidence for an actual subcellular pathway--and it looks like it might actually be autophagy (I admit I am biased, but you can decide for yourself).