Final answer:
Charles Darwin and Alfred Russel Wallace were essential contributors to the development of the theory of evolution in the 19th century, with their ideas on natural selection. They presented their findings in 1858, which culminated in Darwin's publication of On the Origin of Species. Their expeditions to various locations provided the empirical evidence needed to support their theories.
Step-by-step explanation:
Charles Darwin and Alfred Russel Wallace were pivotal figures in the 19th century who contributed significantly to the field of biology through their work on evolution. Darwin's name is often more recognized in relation to the theory of evolution, but Wallace also played an integral role. Both men undertook extensive voyages to the tropics which formed the basis of their observations and hypotheses.
In 1858, Darwin and Wallace presented papers to the Linnean Society which outlined the process of natural selection. This was a groundbreaking moment for science, as it introduced a mechanism by which species could evolve over time. The following year, Darwin published On the Origin of Species, his influential book that outlined his extensive arguments for evolution by natural selection.
Darwin's voyage on the H.M.S. Beagle and observations in the Galápagos Islands, as well as Wallace's research in the Amazon and Malay Archipelago, provided key examples of species with minor variations that suggested adaptive changes over time. Their conclusions regarding the variation in traits leading to better survival and reproduction in specific environments fundamentally altered how we understand life on Earth.