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The Evolutionary Origin And Diversification Of Feathers
Abstract
Progress on the evolutionary origin and diversification of feathers has been hampered by conceptual problems and by the lack of plesiomorphic feather fossils. Recently, both of these limitations have been overcome by the proposal of the developmental theory of the origin of feathers, and the discovery of primitive feather fossils on nonavian theropod dinosaurs. The conceptual problems of previous theories of the origin of feathers are reviewed, and the alternative developmental theory is presented and discussed. The developmental theory proposes that feathers evolved through a series of evolutionary novelties in developmental mechanisms of the follicle and feather germ. The discovery of primitive and derived fossil feathers on a diversity of coelurosaurian theropod dinosaurs documents that feathers evolved and diversified in nonavian theropods before the origin of birds and before the origin of flight. The morphologies of these primitive feathers are congruent with the predictions of the developmental theory. Alternatives to the theropod origin of feathers are critique and rejected. Hypotheses for the initial function of feathers are reviewed. The aerodynamic theory of feather origins is falsified, but many other functions remain developmentally and phylogenetically plausible. Whatever their function, feathers evolved by selection for a follicle that would grow an emergent tubular appendage. Feathers are inherently tubular structures. The homology of feathers and scales is weakly supported. Feathers are composed of a suite of evolutionary novelties that evolved by the duplication, hierarchical organization, interaction, dissociation, and differentiation of morphological modules. The unique capacity for modular subdivision of the tubular feather follicle and germ has fostered the evolution of numerous innovations that characterize feathers. The evolution of feather keratin and the molecular basis of feather development are also discussed.
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“The branched, pennaceous flight feathers of modern birds evolved from the tubular integumentary appendages of early theropod dinosaurs such as Sinosauropteryx, and were subsequently co-opted for an aerodynamic function with the evolution of asymmetrical pennaceous feathers in Paraves”
From Barb geometry of asymmetrical feathers reveals a transitional morphology in the evolution of avian flight (2015) · cites this paper as [3]
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Metadata
- Authors
- Prum, R. O., & Brush, A. H.
- Affiliations
- University of Kansas (US)
- ORCID
- Prum, Richard O.
- Venue
- The Quarterly Review of Biology
- Publisher
- University of Chicago Press
- Published
- 2002-09
- Volume
- 77
- Issue
- 3
- Pages
- 261-295
- ISSN
- 0033-5770 (ISSN-L)
- 1539-7718
- OpenAlex
- W2000286878
- Cited by
- 331
- References
- 102
- Citations by year
- 2026: 11 · 2025: 16 · 2024: 16 · 2023: 14 · 2022: 19 · 2021: 9 · 2020: 21 · 2019: 9 · 2018: 17 · 2017: 16 · 2016: 20 · 2015: 13 · 2014: 11 · 2013: 16 · 2012: 17
- FWCI
- 2.14
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- The Quarterly Review of Biology (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Physical Sciences › Earth and Planetary Sciences › Paleontology › Paleontology and Evolutionary Biology
- Physical Sciences › Earth and Planetary Sciences › Paleontology › Evolution and Paleontology Studies
- Health Sciences › Medicine › Anatomy › Comparative Animal Anatomy Studies
- Keywords
- feather evolution, feather follicle, feather keratin, feather development, evolutionary innovation, origin of birds
- MeSH terms
- Adaptation, Physiological, Animals, Birds, Biological Evolution, Feathers, Keratins, Models, Theoretical, Hair Follicle, Dinosaurs
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