"At 20 days of life, the heart of an evolving human being looks like a worm... At 25 days... a clear-cut... single pump... In a sense, we mirror... a fish... At 30 days, the embryologic heart contains a patent ventricular septal defect and an atrial septal defect... we resemble the amphibian and the reptile... Finally, at 50 days... an intact atrial and ventricular septum.... our cardiac evolution encompasses 1 billion years of the phylogenetic development."