Which species concept classifies organisms based on physical traits?

The morphological species concept is centered on classifying organisms based on their physical characteristics and structural features. This concept focuses on observable traits such as size, shape, coloration, and other anatomical features, making it particularly useful for identifying and distinguishing species, especially in cases where reproductive behavior or genetic information may not be easily accessible or understood.

By emphasizing morphological traits, this concept allows researchers to categorize organisms that may be similar in appearance or behavior, but not necessarily reproductively isolated from one another, which can be a limitation in other species concepts. This approach is particularly advantageous in paleontology and cases where species are extinct and cannot be studied through ecological interactions or reproductive capabilities.

Overall, the morphological species concept serves as a foundational approach in taxonomy and biodiversity assessment, highlighting the importance of physical traits in understanding the diversity of life forms.