GENOMICS: Journey to the Center of Biology
E. S. Lander
2000
Science
Without doubt, the greatest achievement in biology over the past millennium has been the elucidation of the mechanism of heredity. Heredity is surely the strangest of physiological processes: Organisms encapsulate instructions for creating a member of their species in their gametes, these instructions are passed on to a fertilized egg, and then they unfold spontaneously to give rise to offspring. The ancient Greeks puzzled over these remarkable phenomena. Hippocrates imagined that instructional
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... particles were gathered together from throughout the adult body, having been shaped by experience, while Aristotle believed that the instructions were constant and inherent in the gametes. But philosophers could do no more than speculate for the ensuing 2000 years, because there was no way to probe the physical nature of these instructions. How the nature of heredity came to be understood over the past 200 years is an extraordinary tale of scientific progress. In dizzying succession, biologists found that the heredity instructions followed specific rules of transmission, resided in the chromosomes contained in the nucleus, were embodied in the molecule DNA, were written in a precise genetic code, and could be read out in their entirety to specify organismic shape and function. The solution to the problem of heredity turned out to have breathtaking elegance and generality. The instructions for assembling every organism on the planet--slugs and sequoias, peacocks and parasites, whales and wasps--are all specified in DNA sequences that can be translated into digital information and stored in a computer for analysis. As a consequence of this revolution, biology in the 21st century is rapidly becoming an information science. Hypotheses will arise as often in silico as in vitro. In this essay, we recount how this came to pass. Mendel's Revolution: Transmitting the Instructions Heredity was the province of philosophers until Anton van Leeuwenhoek's invention of the simple microscope in the 17th century. Ironically, early microscopic studies diverted the field; observers convinced themselves that they could see tiny, preformed homunculi ensconced within individual spermatozoa. Preformation obviated the need to store and transmit instructions, but it raised perplexing philosophical questions, such as whether the entire human lineage resided, like nested Russian dolls, in Adam's sperm, and what role Eve played. Scientific studies of heredity eventually emerged from a more practical quarter-economic forces driving improvements in agriculture. The Age of Discovery from the early 15th to the late 18th century brought thousands of new plant species to Europe, many of which were propagated and hybridized, improved cultivars being highly prized.
doi:10.1126/science.287.5459.1777
pmid:10755930
fatcat:nkpwxusjjrcqtmww5cfxfsoymq