Alfred Cosby's "Ecological Imperialism" (Book Note)

 In Ecological Imperialism, Crosby presents a compelling thesis regarding the pivotal role played by biological agents - namely weeds, cultivars, diseases, and animals - in facilitating Europe's unprecedented global expansion and dominance over the past five centuries. Contrary to conventional narratives of European exploration and settlement, Crosby contends that the success of European endeavors was intrinsically intertwined with the dissemination of their biological allies, effectively engendering what he terms "Neo-Europes" across the world. This conceptualization posits that European prosperity was contingent upon the ecological compatibility of their biological cohorts, thereby dictating the regions where European settlements would flourish.

 

Crosby anchors his historical exposition within the broader frameworks of evolutionary biology and geologic history. He elucidates that the land masses constituting the present continents were once unified in the supercontinent Pangaea, undergoing subsequent fragmentation due to intricate geological processes, now known as plate tectonics. Consequently, continents evolved into semi-autonomous ecological theaters, fostering distinct trajectories of biological evolution. While earlier life forms exhibited a pan-global distribution, recent forms emerged in fragmented environments, isolated from one another. Crosby underscores that this centrifugal evolutionary trend, persistent for approximately 200 to 180 million years, experienced a reversal, catalyzed by human intervention in the ecosystem. This shift, inaugurated around half a millennium ago, heralded the dominance of centripetal forces, in stark contrast to the historical norm. While antecedent scholars, notably Elton and biogeographers, have alluded to this phenomenon, Crosby's distinctive contribution lies in his sweeping synthesis of the entire process, complemented by meticulous examinations of localized ecological dynamics.

 

The narrative commences with an exploration of the initial European endeavors in Greenland and the Crusades, revealing their ultimate failure due to intricate biological and epidemiological impediments. Crosby then delves into the rapid triumphs of European settlements in the Atlantic archipelagos of the Azores, Canaries, and Madeiras, intricately interweaving this narrative with a masterful account of the evolution of European maritime prowess. Subsequent chapters dissect Europe's specific biological allies, encompassing the domains of weeds, microbial diseases, and domesticated animals. Notably, Crosby omits an extensive discourse on the European biological incursion into the New World, a subject extensively treated in his prior work, "The Columbian Exchange." Instead, he furnishes an insightful account of the circumstances in New Zealand, exemplifying how his overarching thesis reframes particular historical narratives within a novel analytical framework.

Crosby unfolds a multi-layered narrative, encompassing various threads that converge to shape the course of human expansion and migration over the past five centuries. Beneath the specific accounts of global expansion lies a broader tale of human dispersal across the Earth's surface. Crosby adeptly notes that indigenous populations in the New World and Australia during Europe's recent expansion were themselves earlier migrants from the Old World. While some contention exists on this matter, Crosby aligns with Paul Martin's theories, highlighting the pivotal role of this "first wave" of human migrants in the displacement and extinction of numerous megafauna species, thereby creating ecological opportunities and underutilized niches for subsequent waves of migrants.

 

Crosby interweaves this narrative with a portrayal of the Old World as a densely populated crucible where robust varieties of weeds, grasses, and diseases evolve in tandem with Old World human populations. Simultaneously, New World humans disperse across expansive territories, inadvertently missing the chance to engender highly virulent pathogens. Consequently, the eventual encounter between Old and New World biotic ecosystems through European exploration assumes an inherently asymmetric character. The stage appears prearranged for the unfolding of a biological tragedy, prompting some to interpret Crosby's work as suggestive of a form of biological determinism in historical processes.

 

However, Crosby refrains from pushing this theme to its absolute extreme. Instead, his narrative imparts a heightened sense of human agency and individual responsibility in shaping historical trajectories. The reader departs with a profound appreciation for humanity's role as an active agent within intricate ecosystems, often underestimating their influence while overestimating their deliberate intent. This perspective underscores the dynamic interplay between human agency and environmental contexts, foregrounding the complex web of interactions that underpin historical events.