The paper can be published once the authors more clearly confront their disagreement with the results of Boal and Ng.
In the introduction, this project is put into the context of stromatolites. In the discussion/conclusion, I would appreciate to hear the authors thoughts on what this model teaches us about stromatolites. In the current form I am left to conclude only that communities of filamentous bacteria can develop reticulated patterns similar to forms observed in the fossil record. This conclusion does not offer much more than Shepard’s experimental observation of this result. Can we use the details of this model to, for example, estimate the cohesion β of ancient cells? Do these results provide any insight into the identity of stromatolite building cells. As far as I can tell, nothing in this model suggests that photosynthesis (much less oxygenic photosynthesis) is required to form these patterns. It seems that this model shows that polygonal patters are a generic feature of elongated gliding cells and is independent of metabolism. A quick google search produced this video of mat of the sulfur-oxidizing bacteria Beggiatoa spp. http://vimeo.com/57205513 (note: I have no idea of the details of these observations so any similarity may be spurious).