Criticality in morphogenesis
(Phys.org) —In many regards, a brief time-lapse video can teach more about embryonic development than any amount of reading. It is hard not to be impressed how a repeatable form reliably emerges despite considerable variation in both genes and environment. While it had been hoped that concepts borrowed from statistical mechanics or the ideas of self-organized criticality could help to create some kind of physics-based theory of development, much of what has been done lies only at the level of metaphor. In a paper just released to ArXiv, William Bialek and his colleagues from Princeton University, have taken their search for the signature of criticality in a more specific direction. They looked at a particular set of transcription factors in Drosophila embryos which control spatiotemporal development. By analyzing fluctuations in the expression levels of these so-called gap genes, they found evidence for critical tuning in this particular network.