Self-Organization in Embryonic Development: Myth and Reality

“Self-organization” has become a watchword in developmental biology, characterizing observations which embryonic or induced stem cells derived from animals replicate morphological steps and outcomes seen intact embryos. While the term was introduced eighteenth century by philosopher Immanuel Kant to describe goal-directed properties of living systems, it came into modern use for non-living materials complex forms patterns emerge through dynamical, energy-expending physical processes. What is relationship among these uses term? multicellular arose dozens times single-celled organisms, only some undergo development, not all processes are self-organizing. The evolution (metazoans) unicellular holozoans accompanied addition novel gene products mediated constitution resulting cell clusters as liquid-, liquid crystal-, solid-like with protean morphogenetic propensities. Such variously exhibited multilayering, lumen formation elongation, echoing self-organizing nonliving matter, “generic” based on such parallels, though biologically subunit modes interaction. These effects provided evolutionary starting points templates motifs diverse metazoan lineages. Embryos organ primordia present-day animal species continue generate that resemble effects. Their however, employs overdetermined, highly evolved mechanisms often disconnected their originating Using examples gastrulation, somitogenesis, limb skeletal this chapter provides instances of, conceptual framework understanding, relationships between transparently types self-organization.