Photosynthetic complexes transfer absorbed energy among pigment molecules with remarkable efficiency. Researchers hypothesized that short-lived quantum coherence helps guide energy through several routes rather than through a purely random hopping process. Ultrafast spectra showed synchronized oscillations among pigments during the first stages of transfer. A mutation that changed the spacing of two pigments shortened those oscillations and reduced transfer efficiency, although absorption strength and total pigment number were unchanged. Raising environmental noise gradually erased both the oscillations and the mutant-normal efficiency difference.