How can an organism grow to form a desired structure and pattern? Understanding the morphogenesis of an organism, the collective self-organization of cells that gives rise to a functional structure, is at the heart of decoding life. We aim to identify the rules of development by studying the physical principles underlying the formation and adaptation of biological organisms. Currently, we investigate the mechanics of plant growth and the fluid dynamics enabling the slime mold Physarum polycephalum to adapt its network-like body to its environment. Our approach combines both theoretical physics and experiments. Theoretically, we use analytical and numerical methods from mechanics, fluid dynamics, statistical physics, and non-linear dynamics. On the experimental side, we investigate the adaptation dynamics of Physarum polycephalum with bright-field microscopy, transformations, micro-injection, and tailored quantitative analysis. As a recent addition to our experimental side, we investigate animal vasculature formation and adaptation in vitro and follow porous media’s flow and transport dynamics.