Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck

Jean-Baptiste Lamarck was a 19th-century French naturalist who proposed that organisms evolve over time through a process called inheritance of acquired characteristics—meaning traits developed during an organism’s life can be passed to their offspring. For example, he suggested that if a person developed strong muscles by working out, their children might inherit some of that increased strength. Although his ideas were later replaced by Darwin’s theory of natural selection, Lamarck made important contributions by emphasizing that species change over generations. His work helped shape the modern understanding of evolution.