The delicate transition between the proliferation of progenitor cells and their differentiation is critical to successful organogenesis; subtle alterations in this process can lead to serious developmental disorders. The bone morphogenic protein (BMP) and fibroblast growth factor (FGF) signaling pathways, are among the most intensively studied signaling mechanisms regulating organogenesis, although the precise dynamic crosstalk between these signaling pathways, and its influence on development, remain obscure. Using genomic and system biology approaches as well as manipulations of signaling molecules in vitro and in vivo in chick embryos, we demonstrate that the switch from proliferation to differentiation of cardiac progenitors is regulated in a spatiotemporal manner via BMP-mediated inhibition of FGF signaling. In addition, inhibition of the FGF-ERK signaling pathway is both sufficient and necessary to promote cardiomyocyte differentiation and beating. We suggest that BMP and FGF act via inter- and intra-signaling pathway feedback loops, to enable progenitor cells to either proliferate or differentiate at the right time and place. Another unpublished study reveals that FGFs are negatively correlated with myogenic differentiation during embryogenesis. Furthermore, inhibition of FGF/ERK signaling in vitro and in vivo induced myogenic differentiation, possibly through a cell cycle arrest. We suggest that ERK signaling pathway is activated in response to FGF signals to inhibit cardiac and skeletal muscle differentiation in a non-cell autonomous manner. Our studies could lead to new insights into the stepwise manipulation of ERK signaling to promote muscle regeneration during adulthood.