With our method, DNA nanostructures spontaneously self-assembled at constant temperature and progressively evolved toward their equilibrium state by exploring multiple folding pathways through a complex free energy landscape without being kinetically trapped. To explore the applicability of such a unique thermodynamic control, we mixed the M13 scaffold with an equimolar mixture of two sets of staples coding for origami shapes of different stability, in this case triangles versus staple edge-free rectangles. Properly folding rectangle would lead to 1105 unpaired bases for 64 free ends, i.e., double stranded helices that have no neighboring base pair and thus no stacking partner, while the triangle structures involved only 97 unpaired bases and 54 free ends. We could thus expect the triangle to be on a lower energetic level and therefore thermodynamically more stable since more bases of the scaffold are paired in the fully assembled state. We let the system evolve at 25 °C in TANa buffer ([NaCl] = 100 mM). Regardless of the incubation time, from a few minutes to several days, we did not detect any rectangular shapes, neither partial or complete, nor any triangle-rectangle chimera. In contrast, we observed the progressive self-assembly of triangle origamis only (Fig. ), showing that the system spontaneously evolved toward the lower free energy minimum and, as such, was capable to self-select its most stable state in a complex pool of multiple and competing components. We thus expect that chimera could appear but only when they correspond to a free energy minimum. Then, we prepared rectangle origamis in TANa ([NaCl] = 100 mM) by thermal annealing, and exposed them without any purification, i.e., keeping the rectangle staples in solution, to additional staples coding for sharp triangles and let the system evolve at a constant temperature (Fig. , top row). Remarkably, at 30 °C and with a 10-fold excess of triangle staples, rectangles disappeared in time to be progressively replaced with an increasing amount of triangular structures. This process was probably facilitated by the large amount of unpaired bases on the rectangle edges. With a concentration much lower than that of each staple, the M13 scaffold was the limited reagent in this system. We thus witnessed what appeared to be the first giant origami shape transformation by massive strand displacement of all of its constitutive staples. We further exploited this feature to tune the efficiency and speed of the transformation. To this end, we identified the staples in the rectangle structures binding by one extremity to a sequence of 8 consecutive bases of the scaffold sequence that was bound by a unique staple in the edges of the triangle structure (see Materials and Methods section for details). 48 staples of the rectangle were satisfying this criterion. We created shortened versions of these staples by removing the three first (5' side) or last (3' side) bases to these specific extremities, and repeated the isothermal transformation experiment using 20 or 48 shortened staples in the initial rectangle design. In this case (Fig. , middle and bottom rows), rectangles disappeared in one day only while it took over 40 days with full-length staples. This was accompanied by a faster formation of triangles at a rate increasing with an increase in the fraction of shortened staples, i.e., increasing amounts of toeholds to initiate the formation of the triangle edges. With 48 shorter staples, the initial rectangles displayed a looser structure but the transformation was particularly efficient with 88.1 % of origamis having a triangular shape with at least one well-formed corner after 4 days of isothermal transformation. After 42 days, 93.4 % of the origamis were perfectly formed triangles. Using a higher salt concentration ([NaCl] = 150 mM) at 30 °C led to the stabilization of the initial rectangle structures and shortening the staples was necessary to observe significant transformation into triangles (Fig. ). With [NaCl] = 100 mM but at 25 °C, rectangles slowly acquired a looser structure but did not transform into triangles within the 54 days of the experiment. Shortening the staples significantly improved the process and transformation from rectangle to well-formed triangles was observed in a few days with a kinetic and efficiency comparable to that at 30°C (Fig. , Table ), while decreasing the triangle over rectangle staple ratio from 10 to 1 resulted in a much slower transformation, even in the presence of shortened staples (Fig. , Table ). All these results demonstrated that our self-assembly method allowed one to achieve spontaneous evolution under thermal equilibrium from one origami shape to a dramatically different one when the system is exposed to a competitive set of staples leading to a thermodynamically more stable shape. Based on a multicomponent massive strand displacement process, the kinetic of this transformation was strongly dependent on the staple composition and could be accelerated and adjusted by increasing the ratio of competitive staples and creating toeholds in the initial shape.