Heterochrony refers to changes in the timing of developmental events. and it is precisely regulated in the organisms by the heterochronic genes such as C. elegans lin-4 and let-7. Mutations in these genes cause precocious or retarded development of certain cell lineages. https://www.roneverhart.com/Doorking-2334-080-VoIP-RS-232-Control-Box-for-1830-Series/