Comparative anatomy

Comparative anatomy studies similarities and differences in the anatomical structures of organisms. It helps reveal how body forms relate to shared ancestry, adaptation, and development.

Homology: Similarity between biological structures due to shared ancestry, even when their functions differ. Shared structural patterns are evidence of common descent.
Phylogenetics: The study of evolutionary relationships among organisms, commonly represented as branching trees. Shared anatomical characters can help infer branching relationships.
Pentadactyl limb: A limb with five digits or a modified form of the five-digit arrangement found in many tetrapods. Its varied forms illustrate how homologous structures can serve different functions.
Comparative physiology: The study of physiological similarities and differences among organisms. It compares how bodies function rather than primarily how they are structured.
Analogy (biology): Similarity between traits that evolved independently, often because organisms faced similar functional demands. Similar functions can arise without a shared anatomical origin.
Cladistics: A method of classifying organisms by shared derived traits and grouping them into clades. It turns comparative traits into explicit hypotheses of relationship.
Archaeopteryx: An extinct Jurassic animal known from fossils combining birdlike and non-avian dinosaur features. Its skeleton preserves a notable mixture of anatomical traits.
Comparative embryology: The comparison of embryonic development across organisms to identify shared and divergent patterns. Developmental stages provide evidence alongside adult anatomical structures.
Body plan: The general arrangement of an organism's major structural features and organ systems. Comparisons often begin with broad patterns shared across groups.
Paleontology: The scientific study of ancient life through fossils and other traces of past organisms. Comparisons with living anatomy help interpret fossil structures.

Linked from 87 pages