The concept of organic evolution is central to physical and biological anthropology, as it explains the origin, development, and diversification of species, including humans. Organic evolution refers to the gradual and cumulative changes in the heritable characteristics of populations over successive generations. These changes lead to the formation of new species and the adaptation of organisms to their environments. Several theories have been proposed to explain the mechanisms of organic evolution, ranging from early philosophical ideas to more scientifically grounded frameworks. Among the most notable theories are the Lamarckian theory of inheritance, Darwin’s theory of natural selection, the modern synthetic theory of evolution, and mutation theory. Each of these theories offers unique insights into the process of evolution and the factors that drive biological diversity. One of the earliest systematic attempts to explain organic evolution was made by Jean-Baptiste Lamarck in the early 19th century. Lamarck proposed the theory of inheritance of acquired characters, also known as Lamarckism. According to this theory, organisms acquire certain characteristics during their lifetime as a result of environmental pressures or their own actions, and these acquired traits are then transmitted to their offspring. Lamarck emphasized two main principles to explain this process: the principle of use and disuse and the principle of inheritance of acquired characteristics. The principle of use and disuse suggests that organs or structures that are frequently used become more developed, while those that are not used tend to atrophy and diminish over generations. For example, Lamarck argued that the long neck of the giraffe evolved because ancestral giraffes stretched their necks to reach leaves in tall trees, and this trait was gradually inherited by subsequent generations. Similarly, he believed that the development of muscles in blacksmiths’ children would be influenced by the parents’ physical activity. The theory of inheritance of acquired characters was groundbreaking in its time because it introduced the idea that the environment plays a direct role in shaping the characteristics of living organisms. Lamarck’s perspective highlighted the adaptive significance of traits and the potential for organisms to respond to environmental challenges. However, it was also criticized for lacking empirical support, as no mechanism was clearly demonstrated for how acquired traits could be reliably passed on to offspring. Despite these