Final answer:
Alfred Russel Wallace independently conceptualized the mechanism of natural selection, mirroring Charles Darwin's ideas based on observations from his travels. His work laid the groundwork for the modern synthesis, combining genetics with evolutionary biology for a comprehensive understanding of evolutionary processes.
Step-by-step explanation:
Alfred Russel Wallace, a contemporary of Charles Darwin, played a pivotal role in shaping our initial understanding of evolution and natural selection. Both naturalists independently conceived the mechanism for evolution during their extensive travels. While Wallace is less renowned than Darwin, his work was crucial in confirming the principles of natural selection that Darwin had already considered. Wallace developed his theory while exploring regions like the Amazon rainforest and the Malay Archipelago, where he collected insects and observed distinct species different from but related to those on the nearby mainland.
Contribution to the Modern Synthesis
Although Wallace, like Darwin, was unaware of Gregor Mendel's work on genetics, his insights into natural selection were integral to the development of the modern synthesis. The modern synthesis, which emerged in the 1940s, integrated genetics with evolutionary biology. It provided a coherent framework for understanding how natural selection can influence a population's genetic makeup and, subsequently, lead to the gradual evolution of populations and species through microevolution and macroevolution.