Hans Spemann was a German embryologist born on June 27, 1869, in Stuttgart. He is best known for his pioneering work in developmental biology, particularly for his experiments on the organizer effect in embryos. Spemann's research demonstrated how certain cells can influence the development of surrounding cells, leading to the concept of the morphogenetic field. In 1935, Spemann was awarded the Nobel Prize in Physiology or Medicine for his contributions to the understanding of embryonic development. His work laid the foundation for future studies in genetics and developmental biology, influencing scientists like John Gurdon and Shinya Yamanaka in their research on cell reprogramming.