Nathaniel Rich offers an excellent and thought-provoking review of The Invention of Nature: Alexander von Humboldt’s New World by Andrea Wulf, a biography of Darwin’s inspiration and, arguably, the inventor of our modern world Alexander von Humboldt:
Humboldt’s most consequential findings, however, derived from his conception of the world as a single unified organism. “Everything,” he said, “is interaction and reciprocal.” It seems commonplace today to speak of “the web of life,” but the concept was Humboldt’s invention. Into the seventeenth and eighteenth centuries, thinkers like René Descartes, Francis Bacon, and Carl Linnaeus were still echoing Aristotle’s view that “nature has made all things specifically for the sake of man.”
Particularly heterodox was the implication that the decline of one species might have cascading effects on others. The possibility that animal life might not be inexhaustible had been proposed by the German anatomist J.F. Blumenbach (who taught Humboldt at the University of Göttingen), but was not widely accepted. “Such is the œconomy of nature, that no instance can be produced of her having permitted any one race of her animals to become extinct,” declared Thomas Jefferson in 1784, an opinion shared by most naturalists. Convinced to the end of his life that mastodons still existed in North America, most likely in the “unexplored and undisturbed” regions of the continent, Jefferson urged Lewis and Clark to look for them during their expedition.
Humboldt traveled so far, saw so much, and observed so closely that he began to notice similarities across continents. Rhododendron-like plants on the mountains near Caracas reminded him of alpine trees in the Swiss Alps; a sea of cacti, seen from the distance, recalled the grasses in the marshes of northern Europe; a moss in the Andes resembled a species he had found growing in German forests.
This comparative approach allowed him to take staggering intellectual leaps. He looked beyond the characteristics of organisms and tried to determine the structures underlying nature, leading him to formulate the idea of ecosystems. He was the first to understand that climate emerged from the “perpetual interrelationship” between land, ocean, wind, elevation, and organic life. He introduced the idea of classifying plants by climate zones instead of taxonomy, taking into account altitude, temperature, and other conditions related to location. He invented isotherms, the lines used on maps to connect regions with the same average temperature and atmospheric pressure. The similarity of the coastal plants in Africa and South America led him to postulate an “ancient” connection between the continents, anticipating plate tectonic theory by more than a century. He also studied how different systems interacted with one another. Nobody before Humboldt, for instance, had been able to explain how forests, by releasing oxygen, storing water, and providing shade, have a cooling effect on climate.