Aging research in 19th century biology

Humans have learned from experience that time is a factor that reveals change. In combination with the conception that an individual’s life is limited, this has lead to the conclusion that organisms undergo a process of alterations during their lifetime, which is called aging. The last part of an organism’s life before dying is often referred to as old age, for most life forms a stage of physical decay and frailty.

Aging and old age had not played a crucial role in the biological sciences until it assumed prominence in a debate started by leading scientists in animal biology in Germany in the second half of the 19th century. As the focus expanded and forms of life other than animals and plants became available as scientific objects in the microscopic cosmos, the question arose whether aging and death of old age were inherent in life in general, or if they had to be seen as independent phenomena. As a result, attempts to understand the causes of aging were closely connected with questions of individuality, immortality and the origin of death in the overarching frameworks of evolution and cell theory.

In my research on the history of aging as an object of scientific inquiry, it is of special interest to me if and how boundaries between the use of different objects of study like plant / animal / human, were either crossed or reinforced by the scientists involved. Additionally, I am interested in if and how different levels of observation like cell / organism / population were used to construct different concepts of aging in the diverging fields of the life sciences. My project aims to disentangle these scientific concepts of aging, deeply intertwined in the context of the late 19th century, while bringing to light the course of events that preceded the disciplinary emergence of gerontology at the beginning of the 20th century.