Which scientists developed ideas about natural selection at the same time as Darwin?

Alfred Russel Wallace is the most notable scientist who independently developed a theory of natural selection around the same time as Charles Darwin. In 1858, Wallace sent Darwin a paper outlining his ideas, prompting Darwin to present their findings jointly to the Linnean Society of London. Additionally, other contemporaries, such as Thomas Malthus, influenced the development of evolutionary theory with their work on population dynamics and competition.