This week on How on Earth, Beth talks with Professor Tom LaRocca, professor in the department of Health and Exercise Science at CSU in Fort Collins. His background is in molecular biology and physiology, but he is particularly interested in translational research (using laboratory science to develop practical applications or treatments that can help people). He is especially interested in the biology of healthspan, the period of life during which we are healthy and productive, and in research on ways to increase healthspan. He talks particularly about some of his recent work which has identified genetic marks of our biological age, as opposed to our chronological age or the number of years one has under their belt. You can see his website as well as the Healthy Aging website he and his colleagues maintain.