Report, if you have a problem with this page“ The rediscovery of Mendel's laws of heredity in the opening weeks of the 20th century sparked a scientific quest to understand the nature and content of genetic information that has propelled biology for the last hundred years. The scientific progress made [since that time] falls naturally into four main phases, corresponding roughly to the four quarters of the century.""The first established the cellular basis of heredity: the chromosomes. The second defined the molecular basis of heredity: the DNA double helix. The third unlocked the informational basis of heredity [i.e. the genetic code], with the discovery of the biological mechanism by which cells read the information contained in genes, and with the invention of the recombinant DNA technologies of cloning and sequencing by which scientists can do the same." The sequence of the human genome, the project asserted, marked the starting point of the "fourth phase" of genetics. This was the era of "genomics" - the assessment of the entire genomes of organisms, including humans. There is an old conundrum in philosophy that asks if an intelligent machine can ever decipher its own instruction manual. For humans, the manual was now complete. Deciphering it, reading it, and understanding it would be quite another matter. ”