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The molecular evolution of feathers with direct evidence from fossils.

ABSTRACT: Dinosaur fossils possessing integumentary appendages of various morphologies, interpreted as feathers, have greatly enhanced our understanding of the evolutionary link between birds and dinosaurs, as well as the origins of feathers and avian flight. In extant birds, the unique expression and amino acid composition of proteins in mature feathers have been shown to determine their biomechanical properties, such as hardness, resilience, and plasticity. Here, we provide molecular and ultrastructural evidence that the pennaceous feathers of the Jurassic nonavian dinosaur Anchiornis were composed of both feather ?-keratins and ?-keratins. This is significant, because mature feathers in extant birds are dominated by ?-keratins, particularly in the barbs and barbules forming the vane. We confirm here that feathers were modified at both molecular and morphological levels to obtain the biomechanical properties for flight during the dinosaur-bird transition, and we show that the patterns and timing of adaptive change at the molecular level can be directly addressed in exceptionally preserved fossils in deep time.

SUBMITTER: Pan Y

PROVIDER: S-EPMC6386655 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

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The molecular evolution of feathers with direct evidence from fossils.

Pan Yanhong Y Zheng Wenxia W Sawyer Roger H RH Pennington Michael W MW Zheng Xiaoting X Wang Xiaoli X Wang Min M Hu Liang L O'Connor Jingmai J Zhao Tao T Li Zhiheng Z Schroeter Elena R ER Wu Feixiang F Xu Xing X Zhou Zhonghe Z Schweitzer Mary H MH

Proceedings of the National Academy of Sciences of the United States of America 20190128 8

Dinosaur fossils possessing integumentary appendages of various morphologies, interpreted as feathers, have greatly enhanced our understanding of the evolutionary link between birds and dinosaurs, as well as the origins of feathers and avian flight. In extant birds, the unique expression and amino acid composition of proteins in mature feathers have been shown to determine their biomechanical properties, such as hardness, resilience, and plasticity. Here, we provide molecular and ultrastructural ...[more]

PMID: 30692253

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The molecular evolution of feathers with direct evidence from fossils.

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The molecular evolution of feathers with direct evidence from fossils.

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