Developmental science is a broad term that collectively includes Embryology and Developmental Biology. In the present era, each of these specialty has multiple subspecialties and niches. Here, we are interested to look back in time, the beginning of curiosity and the journey of understanding of reproduction step by step, from sperm in 600 BC to ovum, fertilization, assisted reproductive techniques, in vitro fertilization, inter-species chimera and CRISPR/Cas9 in 2018. The eras of discovery included 600 BC to 1827 (first), 1827 to 1950s (second) and 1950s to present (third). Discoveries and research have always been excited in every era and were highly influenced by the biotechnological advancements. Today, CRISPR/Cas9 is the future of embryo editing with therapeutic potentials and ability to shape the human future. In spite of its prematurity and technical limitations, it is still an active area of research at the cross-points of gene editing, developing inter-species chimeras, treatment of infertility, cure of genetic diseases and organ transplantation.