The philosophy of biology is a subfield of philosophy of science, which deals with epistemological, metaphysical, and ethical issues in the biological and biomedical sciences. Although philosophers of science and philosophers generally have long been interested in biology, philosophy of biology emerged as an independent field of philosophy in the 1960s and 1970s.
During that time, philosophers of science began paying increasing attention to biology, from the rise of Neodarwinism in the 1930s and 1940s, to the discovery of the structure of DNA in 1953, and to more recent advances in genetic engineering. Other ideas such as the reduction of all life processes to biochemical reactions as well as the incorporation of psychology into a broader neuroscience were also addressed.
Biologists with philosophic interests responded, emphasising the dual nature of the living organism. On the one hand there was the genetic program; the genotype. On the other there was its extended body or soma; the phenotype. In accommodating the more probabilistic and non-universal nature of biological generalisations, it was a help that standard philosophy of science was in the process of accommodating similar aspects of 20th century physics.