Biology became one field only in the nineteenth century
People studied plants, animals, and bodies for millennia, yet biology as a unified science crystallized in the 1800s. Aristotle dissected dozens of species; Leeuwenhoek opened a microscopic world; Darwin tied diversity to natural selection. Genetics and DNA then split and later rewove the discipline.
Roots run through Ayurveda, Egyptian medicine, and Greco-Roman writers such as Aristotle, Theophrastus, and Galen, later preserved and extended by scholars including Avicenna. The Neolithic Revolution about ten thousand years ago was an early knowledge pivot as domestication demanded intimate organism lore. Egyptian surgical and drug papyri such as Edwin Smith and Ebers date near 1600 BCE. Aristotle classified five hundred forty animal species and dissected at least fifty; Theophrastus’s botanical books anchored plant study into the Middle Ages.
Separate streams arose in China and India: Taoist thinkers such as Zhuangzi in the fourth century BCE questioned species fixity; Ayurveda from about 1500 BCE detailed humours, tissues, and surgery—the Sushruta Samhita lists hundreds of medicinal plants and preparations. Renaissance empiricism revived anatomy with Vesalius and Harvey; Linnaeus and Buffon ordered living diversity; microscopy revealed microbes and fed cell theory. Humboldt linked organisms to geography, seeding ecology and biogeography.
Nineteenth-century synthesis folded together Darwin’s account of species change through natural selection, the collapse of spontaneous generation, and germ theory—yet how traits passed on stayed murky until Mendel’s rules resurfaced via Carl Correns and powered Thomas Hunt Morgan’s fly genetics. By the 1930s population genetics joined selection in the neo-Darwinian synthesis. Watson and Crick’s DNA structure, the Central Dogma, and the genetic code then cleaved organismal from molecular biology—until late-century genomics and proteomics began stitching whole-organism and molecular approaches together again.
Source: History of biology
