Nicole Marthe Le Douarin was one of the first progressive female pioneers of developmental and embryological research. Some of her most notable and ground-breaking work involves grafting quail and chicken embryos together in order to study the developmental fate of each contributing embryo. Le Douarin was born in Brittany, France, on 20 August 1930. As an only child she was inspired by her mother, a school teacher at the time, to develop a passion for learning. According to Le Douarin her father was an open-minded businessman who, likely because she was an only child, raised her much like a boy. In 1944 Le Douarin was forced to move out of her hometown of Lorient and attend a boarding school in Nantes, France, to escape the invasion of German forces during World War II. After the war, she returned to her high school in Lorient, where she received her baccalaureate in 1949. During her last year in Lorient, when she was only seventeen, Douarin met her fianc_. After graduating, and against the wishes of her mother, she moved with him to Paris where they attended the Sorbonne. In 1951, after three years of courtship and university classes together, the couple was married. Le Douarin graduated from the Sorbonne with a degree in the natural sciences in 1954. Instead of immediately continuing to graduate school, she chose to teach science at a local high school and raise a family.

Clifford Grobstein was a traditional, influential, and highly innovative biologist of the mid-twentieth century, gifted with many character facets and pragmatic talents. His early adulthood passion of linking classical embryology with developmental anatomy and medicine was joined by his later pursuit of combining research ethics and science education with public policy.

Homeobox genes are a cluster of regulatory genes that are spatially and temporally expressed during early embryological development. They are interesting from both a developmental and evolutionary perspective since their sequences are highly conserved and shared across an enormously wide array of living taxa.

When placental mammals are born their circulatory systems undergo radical changes as the newborns are prepared for independent life. The lungs are engaged, becoming the primary source of fresh oxygen, replacing the placental barrier as a means for blood-gas exchange.