Alfred Russel Wallace's major contributions include independently co-discovering the theory of evolution by natural selection, pioneering the field of evolutionary biogeography (including the famous Wallace Line), and extensive fieldwork that yielded massive specimen collections and insights into topics like warning coloration (aposematism), significantly influencing biology and natural sciences.
Key Scientific Contributions:
Theory of Natural Selection: Developed the concept of natural selection independently of Darwin, leading to their joint presentation in 1858, which spurred Darwin to publish On the Origin of Species.
Evolutionary Biogeography: Defined the field by studying geographic patterns of species distribution, notably proposing the "Wallace Line," a biogeographical boundary separating Asian and Australian fauna in the Malay Archipelago.
Fieldwork & Specimen Collection: Conducted extensive expeditions (Amazon, Malay Archipelago) and collected over 100,000 specimens, greatly expanding scientific knowledge and collections for institutions like the Natural History Museum.
Warning Coloration (Aposematism): Studied how bright colors in animals (like butterflies) signal danger to predators, a key concept in evolutionary biology.
Speciation: Pioneered early theories on how new species form through adaptation to environments.
Interdisciplinary Work: Made contributions to anthropology, ethnography, epidemiology, astrobiology, and social reform, advocating for land reform and women's rights.
Impact:
His work provided crucial empirical evidence for evolution, validating both his and Darwin's ideas.
His detailed observations laid the groundwork for modern understanding of species distribution and evolution.
He remains recognized as a co-founder of evolutionary theory and a foundational figure in biogeography.