Evolution, Old & New Or, the Theories of Buffon, Dr. Erasmus Darwin and Lamarck, as compared with that of Charles Darwin Book Summary

One of the most striking lessons is the realization that the idea of evolution wasn’t a sudden revelation. Buffon, in the 18th century, already questioned the fixity of species, suggesting they could ‘degenerate’ from an original ideal form due to environmental pressures. This wasn’t a full-blown theory of common descent, but it challenged the prevailing belief in a static, divinely created world. For example, Buffon noted similarities between different species of animals, suggesting a possible shared origin, a radical thought for his time.

The book highlights the importance of considering the historical context of scientific ideas. Erasmus Darwin, Charles’ grandfather, published “Zoonomia” in 1794-96, which explicitly proposed a theory of evolution, suggesting that organisms gradually change over time and all animals descend from a common ancestor. However, his work lacked the rigorous evidence and the compelling mechanism that would later define Darwin’s success. Butler points out that Erasmus Darwin’s ideas were often presented as poetic speculation rather than scientific hypothesis.

Lamarck’s theory of inheritance of acquired characteristics receives significant attention. Lamarck believed that organisms could pass on traits developed during their lifetime to their offspring. The classic example is the giraffe: according to Lamarck, giraffes stretched their necks to reach higher leaves, and this stretching resulted in offspring with longer necks. While ultimately disproven in its original form, Lamarck's work was critical in establishing that organisms could *adapt* to their environment, a concept Darwin built upon. Butler dissects Lamarck's reasoning, noting its reliance on a kind of vital force and lack of empirical support.

Finally, the book demonstrates how Darwin’s contribution wasn’t just the idea of evolution, but the power of natural selection as an observable, testable mechanism. Darwin provided a way to explain *how* evolution happened, driven by the differential survival and reproduction of individuals with advantageous traits. He wasn't the first to suggest life changed, but he was the first to convincingly explain *why* and *how* it changed, transforming the field from speculation to scientific inquiry.

• You're interested in the *history* of science, particularly evolutionary biology.
• You enjoy reading older writing styles and aren’t necessarily looking for a modern textbook.
• You want to understand the intellectual climate that preceded Darwin's theory.
• You’re curious about how ideas evolve *before* becoming fully formed scientific theories.
• You appreciate a somewhat provocative and contrarian authorial voice.