Final answer:
Political parties have at times paralleled ideologies with theories such as Social Darwinism, which applied Darwin's natural selection principles to societal and political structures. This justified the status quo based on natural fitness, but was criticized for lacking consideration of equal opportunity and led to its decline in political relevance.
Step-by-step explanation:
The ideological trends in political parties can often be paralleled with theories outside of the political realm. Social Darwinism, inspired by Charles Darwin's theory of evolution, is one example that has been applied to the political ideology landscape. Darwin’s theory, which posited that species evolve through natural selection, with advantageous traits becoming more common in a population, was adapted to social theory. Herbert Spencer coined "survival of the fittest" and applied Darwinian principles to human societies, suggesting that social progress is due to the natural superiority of some individuals or groups.
Business leaders and elite theorists used Social Darwinism to justify the status quo of their wealth and societal positions, equating success with natural fitness. This approach to society and politics contended that if business and societal positions were left to natural competition, without interference, the 'fittest' would naturally rise to the top. However, this completely neglected the lack of equal opportunity and the role of chance, luck, and social support networks in individuals' success. The misapplication of Darwin's biological theories to social and political realms facilitated the justification of wealth disparities, class distinctions, and even colonialist actions.
By the 1930s and 1940s, Social Darwinism's association with eugenicists and theories of genetic superiority drew widespread criticism, and its influence on political ideology waned. Today, political scientists recognize the flaws in Social Darwinist thinking and stress the complexity of political party trends that cannot be explained through simple natural selection analogies.