Why is Lamarck considered an important early theorist of evolution despite the rejection of Lamarckism?

Jean-Baptiste Lamarck is recognized as a foundational figure in the history of biology not because his specific mechanism of inheritance was correct, but because he was the first naturalist to propose a comprehensive, systematic theory of organic evolution to explain the diversity of life on Earth.1

While Lamarckism—the idea that traits acquired during an organism's lifetime can be passed to offspring—has been discredited by modern genetics, Lamarck’s work was revolutionary for its time. He moved beyond static views of nature by arguing that species are mutable and that life forms change over time in response to their environment.123

By detailing how small, accumulated changes could lead to major transformations, Lamarck provided a framework that influenced evolutionary thought throughout the 19th century, even impacting Charles Darwin, who initially incorporated aspects of acquired inheritance into his own theories. Ultimately, Lamarck’s importance lies in his role as a pioneer who established the scientific necessity of explaining how all living forms are connected through a process of transformation.134