Jean-Baptiste Lamarck was a French naturalist born in 1744, known for his early contributions to the field of evolution. He proposed the idea of inheritance of acquired characteristics, suggesting that organisms could pass on traits they developed during their lifetime to their offspring. This theory was a significant departure from the ideas of his contemporaries. Lamarck's work laid the groundwork for later evolutionary theories, including those of Charles Darwin. Although his ideas were eventually overshadowed by Darwin's theory of natural selection, Lamarck's emphasis on adaptation and change in species was influential in shaping the study of biology.