What concept did Lamark introduce related to evolution?

Lamarck introduced the concept of the "Inheritance of Acquired Characteristics," which suggests that traits or characteristics that an organism develops during its lifetime can be passed on to its offspring. This idea was groundbreaking at the time because it provided a mechanism for explaining how species could change over generations. For example, Lamarck theorized that if an organism used a particular body part more frequently, that part would become stronger or more developed, and those changes would then be inherited by the next generation.

While modern evolutionary theory, particularly Darwin's theory of natural selection, has largely replaced Lamarck's ideas, his contributions laid important groundwork for understanding evolution. By proposing that organisms can change over time in response to their environment, Lamarck helped stimulate further investigation into evolutionary processes, even if subsequent research has shown that inheritance works through genetic mechanisms rather than the direct transmission of acquired traits.