History of Biology
In my last post, I set forth a three part history of knowledge, drawing on, but not identical to, Michel Foucault’s archaeology of human sciences in The Order of Things. It goes something like this:
Period Knowledge is
1300-1600 The Renaissance hidden in the world
1600-1800 The Enlightenment best way of comprehending the world
1800-1950 The Modern Period historical state of belief about the world
Foucault goes on to label the categorization of knowledge in these periods as Similitude (recognizing the hidden correspondences), Taxonomy (applying the right framework within which everything fits), and History (understanding the progression of ideas and events in time). Biology fits neatly into this history. (Note that Foucault, a modern thinker, wants a time series of how people thought when. The very idea is somewhat alien to the earlier modes of thought.
In the Renaissance, living things were ordered in terms of their relationship. One famous example was the scala naturae, the great chain of being that connects all things in the universe in one massive pyramid, from the abundant blind stones up to the unitary omniscient God. Their importance, was inherently relational, as each one forms a link in a chain that makes up reality. Alternatively, they could be compared to a creature with the rocks as bones and God as the soul or mind.
In the Renaissance there was no zoology or biology in the modern sense, but their were menageries and bestiaries. Menageries were not zoos, but collections of animals that demonstrated the breadth of knowledge and sovereignty of the rulers who kept them. They made both represented and exemplified mastery.
Likewise, bestiaries were books filled with information about animals, but they were quite different from a modern zoological textbook. Bestiaries contained information about the features and habits of each animal, but also listed all the ways in which the animal was related to other areas of knowledge: medical and legal and moral significance as well of tales of their interactions with humans. Bestiaries revealed relationships. They did not differentiate between the what we think of as real and mythical animals, because often the symbolism of both was important to readers. For example, the lion and the unicorn on the royal coat of arms (UK) represent the kingdoms of England and Scotland, but they also represent spiritual and temporal power.
In the late 16th century, we begin to see taxonomies in biology, lists of creatures with their observable traits and habits organized systematically by their relationships one to another. What traits do they share in common? Where do they differ? What traits are essential to each group? What traits vary? This was a new way of thinking about biology. It was tied in with the origins of empirical (sense data based) reasoning and modern science. It had everything to do with observation and recording things in tables.
The first biological taxonomy that I could find (in a brief search) was Andrea Cesalpino’s De Plantis , a classification of plants by their seeds and fruits in 1583. Numerous scholars would repeat and add to his observations, sometimes choosing different essential characters as a point of reference.
The most famous Enlightenment taxonomy was Carl Linnaeus’ Systema Naturae (1735), a system for classifying all plants, animals, and minerals. Many of his categories remain important for biology, most notably the “Latin binomial” of genus and species used in scientific communication. Examples include Homo sapiens (humans), Panthera leo (lion), Canis familiaris (dog), and E. (Escherischia) coli (a gut bacterium). These are the two lowest levels in a complex hierarchy of categories Linnaeus used to comprehend (to grasp, but historically to encompass) all things. Many of his categories remain in common as well as scientific use (e.g., Primates – “category one”).
Taxonomic biology started to give way to historical biology around 1800, though the process would take nearly two centuries. Though Darwin is given credit for “evolution”, the idea of species changing through time is older. It was first explained systematically, and quite influentially, by Lamarck in his 1809 Philosophie Zoologique. Lamarck’s mechanism for evolution (inheritance of acquired characters) turned out to be incorrect, but he managed to convince many biologists that species were impermanent. Charles Darwin and Alfred Russel Wallace would provide a better mechanism. Darwin’s On the Origin of Species by Means of Natural Selection (1859) argued compellingly and with abundant data, that evolution occurred because some individuals survived and reproduced better than others.
Contrary to popular belief, this did not immediately turn evolutionary biology into a respectable science. There was a great deal of controversy for 60 years over questions of mechanism, proper observation, and what constituted “better”. It would take Mendel’s work on genes (as units of inheritance) as well as the statistics of the early 20th century to develop a truly historical biology that claimed to trace the states of organisms through time.
Even then, Linnaeus taxonomy, based on similar traits between organisms, remained the organizing principle behind scientific names. Molecular phylogenetics, the ability to reconstruct historical relationships between organisms on the basis of gene and protein sequence data, didn’t begin to take over biological taxonomy until the 1970s. Now our nomenclature ideally (if not always in practice) reflects our best understanding of family relationships between living things, a true tree of life stretching from individual at the leaves to species in the branches and back to a single root. Only recently have we really started to see biology as historical, though the process began around 1800.