“…It is intriguing how developmental patterning achieves a high degree of accuracy Gregor et al, 2007a) and robustness (Inomata et al, 2013;Lucchetta et al, 2005). Two hypotheses have been proposed: one is the thresholddependent model, i.e., the French flag model, which assumes that the positional information is faithfully transferred from precise upstream patterning (Rogers and Schier, 2011;Wolpert, 2011); the other is the self-organized filtering model, which assumes that noisy upstream patterning needs to be refined to form downstream patterning with sufficient positional information Gregor et al, 2007b;Houchmandzadeh et al, 2002;Kanodia et al, 2009;Manu et al, 2009;Yang et al, 2018). The two models have been thought to be mutually exclusive, and it has been extensively debated which one is implemented in a particular developmental system.…”