Final answer:
Lewis Henry Morgan's theory of unilineal evolution focused on technology driving cultural progression, contrasted by Social Darwinism's idea of inherited societal traits. Later challenges and the modern synthesis of genetics with evolution refined our understanding of cultural and biological evolution.
Step-by-step explanation:
Unilineal Evolutionism and Social Darwinism
Lewis Henry Morgan, an American anthropologist, proposed a nuanced version of unilineal evolution, building upon E. B. Tylor's stages of cultural progress. Morgan's hypothesis centered on technology as the catalyst driving cultural evolution. He suggested that the advent of new technologies led to novel social practices and ideologies, which marked a civilization's advancement.
Morgan's ideas stood in contrast to Social Darwinism, which Herbert Spencer derived from Charles Darwin's theory of evolution. Spencer contended that certain societal traits, such as work ethic or laziness, could be inherited, echoing Lamarck's notion of acquired traits and leading to justifications for social inequalities.
However, figures like Franz Boas later challenged the notion of unilineal evolution, emphasizing that cultures develop along their unique historical paths and constantly interact and influence each other. The modern synthesis, integrating genetics with evolution, later solidified the scientific understanding of how populations evolve through natural selection, disputing earlier simplistic views on cultural advancement.
While theories of unilineal cultural evolution have largely been abandoned, they have shaped historical views on social progress and the justification of colonialism.
In summary, while technological advancements were seen as markers of progress within the framework of unilineal cultural evolution, this linear view was later supplanted by more complex understandings of cultural and biological evolution, recognizing the diverse factors that contribute to a society's development.