Julian Steward's 'cultural ecology' represents a significant branch of neo-evolutionism, emerging in the mid-20th century as a reaction against the grand, unilineal evolutionary theories of the 19th century and the extreme cultural relativism of some Boasian anthropologists. Steward proposed a more nuanced approach to cultural evolution, emphasizing the role of the environment and technology in shaping cultural forms.

Steward's core contribution was the concept of multilinear evolution. Unlike unilineal evolutionists who posited a single, universal sequence of cultural development, Steward argued that cultures evolve along multiple, distinct paths. He focused on specific cultural adaptations to specific environments, suggesting that similar environmental challenges could lead to similar cultural adaptations in different parts of the world, a concept he termed 'parallel evolution.'

Central to his theory was cultural ecology, which he defined as the study of how human societies adapt to their environments. Steward believed that the environment, while not solely determining culture, played a crucial role in shaping certain fundamental aspects. He introduced the idea of the cultural core, which comprises the constellation of features most closely related to subsistence activities and economic arrangements (e.g., technology, economy, and the social organization of labor). He argued that this cultural core is primarily shaped by the environment and the technology used to exploit it. Other aspects of culture, which he called 'secondary features' (such as religion, art, and ideology), were considered less directly determined by the environment and could vary more freely.

Steward's method of cultural ecology involved three steps: (1) analyzing the interrelationship between subsistence technology and the environment, (2) analyzing the behavior patterns involved in exploiting the environment, and (3) ascertaining how these behavior patterns affect other aspects of culture.

Critical Examination:

While Steward's approach offered a valuable corrective to earlier theories, it also faced several criticisms:

1. Environmental Determinism: Critics argued that Steward, despite his disclaimers, sometimes leaned too heavily towards environmental determinism, potentially overemphasizing the environment's role and underplaying human agency, historical contingency, and internal cultural dynamics. The 'cultural core' could be seen as too rigid, implying that environment dictates the most important cultural features.

2. Definition of 'Cultural Core': The precise definition and isolation of the 'cultural core' proved challenging in practice. It was often difficult to definitively separate core features from secondary ones, as all aspects of culture are interconnected.

3. Neglect of History and Diffusion: Steward's focus on local adaptation sometimes led to a downplaying of historical processes, migration, and cultural diffusion as significant factors in shaping societies. Cultures are not isolated entities adapting solely to their immediate environment but are also influenced by interactions with other groups.

4. Internal Variation and Power: His framework sometimes overlooked internal social stratification, power dynamics, and individual agency within a culture, tending to treat cultures as monolithic entities adapting uniformly.

5. Applicability: Cultural ecology was more easily applied to small-scale, subsistence-based societies where the human-environment interaction was direct and evident. Its applicability to complex, industrial societies, where the relationship between environment and subsistence is mediated by extensive technology and global economic systems, was less clear.

Despite these criticisms, Steward's neo-evolutionism was highly significant. It shifted anthropological focus from grand, speculative theories to empirical, localized studies of adaptation. It introduced a materialist and ecological perspective that profoundly influenced subsequent anthropological thought, laying groundwork for later approaches like cultural materialism and political ecology. His emphasis on multilinear evolution provided a more flexible and realistic framework for understanding cultural change and diversity.