In eighteenth century Germany, Johann Friedrich Blumenbach studied how individuals within a species vary, and to explain such variations, he proposed that a force operates on organisms as they develop. Blumenbach used metrical methods to study the history of humans, but he was also a natural historian and theorist.
Gunther von Hagens invented a plastination technique and created Body Worlds, a traveling exhibit that promotes public engagement with the study of human anatomy. Von Hagens invented the plastination technique in 1977 while working at Heidelberg University in Heidelberg, Germany.
To study human evolution, researchers sometimes use microstructures found in human teeth and their knowledge of the processes by which those structures grow. Human fetuses begin to develop teeth in utero. As teeth grow, they form a hard outer substance, called enamel, through a process called amelogenesis. During amelogenesis, incremental layers of enamel form in a Circadian rhythm.
Tooth enamel contains relics of its formation process, in the form of microstructures, which indicate the incremental way in which it forms during enamel formation on teeth
Frederik Ruysch made anatomical drawings and collected and preserved human specimens, many of which were infants and fetuses, in the Netherlands during the seventeenth and eighteenth centuries. Ruysch had many interests, including anatomy, botany, and medicine, and he discovered structures of the lymphatic system and of the eye.
Frederik Ruysch’s cabinet of curiosities, commonly referred to simply as the Cabinet, was a museum Ruysch created in the Netherlands in the late 1600s. The Cabinet filled a series of small houses that Ruysch rented in Amsterdam, and they contained greater than 2,000 specimens, including preserved fetuses and infants.