Sandra Madar

Previous analyses have shown that secondarily aquatic tetrapods, including whales, exhibit osteological adaptations to life in water as part of their complex buoyancy control systems. These structural specializations of bone span hyperostosis through osteoporosis. The past 15 years of paleontological effort has provided an unprecedented opportunity to examine the osteological transformation of whales as they make their transition to an obligate aquatic lifestyle over a 10-million-year period. It is hypothesized that whales manifest their osteological specialization in the same manner as extant semiaquatic and fully aquatic mammals. This study presents and analysis of the microstructural features of bone in early and late archaic cetaceans, and in a comparative sample of modern terrestrial, semiaquatic, and aquatic mammals. Bone histology was examined from the ribs of 10 fossilized individuals representing five early cetacean families, including Pakicetidae, Ambulocetidae, Protocetidae, Remintonocetidae, and Basilosauridae. Comparisons were then made with rib histology from nine genera of extant mammals including: Odocoileus (deer), Bos (cow), Equus (horse), Canis (dog), Lutra (river otter), Enhydra (sea otter), Choeropsis (pygmy hippo), Trichechus (sea cow), and Delphinus (dolphin). Results show that the transition from terrestrial, to semiaquatic, to obligate aquatic locomotion in archaeocetes involved a radical shift in bone function achieved by means of profound changes at the microstructural level. A surprising finding was that microstructural change predates gross anatomical shift in archaeocetes associated with swimming. Histological analysis shows that high bone density is an aquatic specialization that provides static buoyancy control (ballast) for animals living in shallow water, while low bone density is associated with dynamic buoyancy control for animals living in deep water. Thus, there was a shift from the typical terrestrial form, to osteopetrosis and pachyosteosclerosis, and then to osteoporosis in the first quarter of cetacean evolutionary history. Anat Rec, 290:638–653, 2007. © 2007 Wiley-Liss, Inc.

The Biomedical Humanities program at Hiram College, established in 1999, engages premedical and other qualified students in ethical and informed decision making, improves their ability to interact with persons of different backgrounds and cultures, provides them an active introduction to basic medical research and clinical practice, and coaches them in communicating across barriers, appreciating that scientists and humanists typically learn and work differently. The program offers both a major and a minor in biomedical humanities topics. The major requires the core biology and chemistry curriculum necessary for further studies in medicine as well as courses in genetics and statistics. The remainder of the major is devoted to four core areas: Communications, Relationships and Cultural Sensitivity, Ethics and Medical Humanities, and a nonacademic core area, Experiential Learning. Many of the ethics and medical humanities options are team-taught interdisciplinary courses. The Experiential Learning area requires students to take two special topics seminars, two service seminars, and two internships-one shadowing a professional in his or her area of interest and one engaging in basic biomedical research. The shadowing internship and service seminars focus not only on career exploration, but also on human interactions. Students reflect on the personal interactions they observe during their various experiences, and on their own strengths and weaknesses. Essays, designed to help students learn more about their roles in these settings, push them to deal with the sociopolitical issues involved in their service. The major, a robust and vital component of Hiram's undergraduate program, has attracted academically gifted students with a diverse array of career goals.