Rooted in antiquity, the possibility and processes of evolution were conceived as philosophical ideas during the times of the ancient Greeks and Romans but have been developed into scientific theory since the time of Charles Darwin.
From the Ancients to the Renaissance
The idea of evolution as biology and not just philosophy dates back to the sixth century B.C. to Anaximander, who advanced a theory on the aquatic descent of mankind. Later Aristotle would articulate the Great Chain of Being (or Scala Naturae) that proposed all species be placed in order from the “lowliest” to “highest” in a ladder-like fashion, with worms on the bottom and God on the top.
Evolutionary thought gradually winked out in Europe after the fall of the Roman Empire. As Christianity arose, the Catholic papal state began to control and dictate most matters, including those of a scientific nature. Life and the planet were explained in religious terms and evolutionary thought was considered rebellious and heretical.
The dawn of the age known as the Renaissance in Europe in the 14th century brought a refreshing questioning of the ideas and beliefs of antiquity in all aspects of human endeavor — culture, art, medicine, and science, as well as a healthy skepticism in the validity of those ancient values.
From the Renaissance to 1900
The word evolution (Latin, evolutio, unroll like a scroll) first appeared in the 17th century in reference to an orderly sequence of events, particularly one in which the outcome was somehow contained within it from the start implying the lack of need for divine intervention. Some evolutionary theories advanced from 1700 to 1850 proposed that the earth, life, and entire universe developed without divine intervention or guidance.
However, most contemporary theories of the time attempted to reconcile biology and spiritualism by postulating that evolution was fundamentally a spiritual process, with the entire course of natural and human evolution being “a self-disclosing revelation of the Absolute.”
In 1809, the French biologist Jean Baptiste de Lamarck attempted to explain the process of evolution in his book Philosophie Zoologique. Lamarck proposed that characteristics which an organism acquired during its lifetime could then be passed on to its offspring. Lamarck’s theory of the inheritance of acquired characteristics would come to be known as “Lamarckism.”
From 1831 to 1836 Charles Darwin served as ship’s naturalist aboard H.M.S. Beagle on a round the world voyage of survey, exploration, and collection with special emphasis on South America. Darwin was barely off the ship before his next great journey – a journey of the mind – began. For the next six years Darwin would ponder and question the biological wonders he had seen. He quietly gathered evidence from every possible source and sought out new ideas to support a notion regarding the transmutation of species that was gaining form and clarity in his thinking.
In November 1859, Darwin’s greatest work, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life was finally published. As Darwin suspected and feared, the book created an instant controversy that continues to this day.
From 1900 to 2000
In the years immediately following Darwin’s death, evolutionary considerations splintered into a number of different interpretations. While the scientific community generally accepted that evolution had occurred, many disagreed that it had happened as explained by Darwin. The ideas of the various disagreeing camps were brought together in the 1930s when Darwinian natural selection and Mendelian inheritance were combined to form neo-Darwinism or Modern Evolutionary Synthesis as it later became known. The Modern Synthesis holds that the processes responsible for small-scale or micro-evolutionary changes can be extrapolated indefinitely to produce large-scale or macro-evolutionary changes leading to major changes and innovation in body form.
In the 1940s and 50s, the identification of DNA as the genetic material by Oswald Avery and colleagues, and the articulation of the structure of DNA by James Watson and Francis Crick revealed the true nature of genes and the genetic material. These discoveries launched the era of molecular biology and transformed our understanding of evolution into a molecular process. Since then, the role of genetics in evolutionary biology has become increasingly central.
In the 1960s Niles Eldredge and Stephen Jay Gould proposed the theory of punctuated equilibrium which held that species remained persistently unchanged phenotypically for long periods of time with relatively sudden and brief periods of speciation resulting in phenotypic change. This theory has been called “evolution by jerks and creeps” as it stands in opposition to the more prevalent view that evolution progresses slowly and steadily.
With the emergence of modern evolutionary synthesis in the 1930s and 1940s, evolutionary biology as an academic discipline in its own right began to appear as well. However, it was not until the 1970s and 1980s that significant numbers of universities had departments specifically geared toward and termed evolutionary biology.
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