Fig. 3: A space for synthetic embodied MC.

Spatial self-organization (SO) rules associated with cell-cell nonlinear interactions are responsible for SO phenomena such as re-aggregation of tissues (a–c) due to differential adhesion (image adapted from ref. ⁷⁶). This SO rule is part of the processes shaping MC embodied complexity, captured in (d) using a 3D space for natural (dark spheres) and engineered or artificially evolved multicellular systems (light spheres). Each system is located in terms of its relative positions, not in quantitative terms. Here, the three axes include (a) spatial complexity (how different cells are distributed over space), (b) developmental complexity (the relative relevance of self-organization and hierarchy participates in the building of the agent) and (c) computational complexity axis. The latter aims to capture the complexity of the computational decision-making actions displayed by each system. The current synthetic MC designs occupy the left corner, where synthetic circuits (dark grey) and embodied systems (light grey) are highlighted. A large void on the right reminds us of the large gap between current achievements and the natural counterparts of MC complexity.