Please note the distinct difference in the interpretation of results from the same study. Nature posits that bacteria are sniffing out their food, while The Scientist posits bacteria are sniffing out each other.
Bacteria sniff out their food. The simplest form of cellular life can scent nutrients from a distance. Nijland, R. & Burgess, J. G. Biotechnology Journal (2010) Source Nature
Bacteria sniff each other out. When sensing the presence of other species, bacteria meet the textbook definition for olfaction. Nijland, R. & Burgess, J. G. “Bacterial olfaction,” Biotechnology Journal, 2010.
There is only one animal model for food choice and for mate choice. Since the animal model is so clearly based on olfaction–even in bacteria–can anyone detail how other animals came to rely on visual perception of attractive physical features for mate choice? The all-too-common visual approach to human physical attraction is akin to the visual perception of attractive foods being causal to the development of food preferences. I discussed this in my July 2, 2010 presentation to the American Mensa Society, as seen in these two 5-minute excerpts from the presentation: