[The nineteenth century roots of the contemporary biological revolution].

The recent publication of the human genomic sequence is the most important progress in biology. It originates from four major watersheds between 1860-1865, namely the biological evolution by Darwin in 1858, the Mendel laws of heredity in 1865, the basis of physiology established by Claude Bernard also in 1865, and the discoveries of microbacteria by Louis Pasteur around 1857. Before 1860, biology did not exist as a science. After 1860, the Darwin's theory progressively became a law after the discovery of the DNA polymorphism and that of the mechanisms of genetic mixing. So far the Mendel's laws were confirmed in parallel with the development of molecular genetics after the discovery of DNA structure and genetic code. The discovery of hormones is one example, amongst several on how integrative physiology applies to Claude Bernard's basis. Finally, based on Pasteur's discovery and Pasteur Institutes, microbiology became a tool for molecular biologists.