Vol. 58, 2019

(update: 2019.07.26; 09.16)
 

Feather Evolution from Precocial to Altricial Birds

Chih-Kuan Chen^1,2,*, Hao-Fen Chuang³, Siao-Man Wu⁴, and Wen-Hsiung Li^2,5,6,*

¹Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, USA. *Correspondence: E-mail: r93b42016@gmail.com (Chen); whli@uchicago.edu (Li)
²Biodiversity Research Center, Academia Sinica, Taipei 11529, Taiwan
³Department of Veterinary Medicine, National Taiwan University, Taipei 10617, Taiwan
⁴Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, München, Germany
⁵The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
⁶Department of Ecology and Evolution, University of Chicago, Illinois 60637, USA

Received 30 May 2019 / Accepted 16 July 2019
Communicated by Benny K.K. Chan

Birds are the most abundant terrestrial vertebrates and their diversity is greatly shaped by the feathers. How avian evolution is linked to feather evolution has long been a fascinating question. Numerous excellent studies have shed light on this complex relationship by investigating feather diversity and its underlying molecular mechanisms. However, most have focused on adult domestic birds, and the contribution of feather diversity to environmental adaptation has not been well-studied. In this review, we described bird diversity using the traditional concept of the altricial-precocial spectrum in bird hatchlings. We combined the spectrum with a recently published avian phylogeny to profile the spectrum evolution. We then focused on the discrete diagnostic character of the spectrum, the natal down, and propose a hypothesis for the precocial-to-altricial evolution. For the underlying molecular mechanisms in feather diversity and bird evolution, we reviewed the literature and constructed the known mechanisms for feather tract definition and natal down development. Finally, we suggested some future directions for research on altricial-precocial divergence, which may expand our understanding of the relationship between natal down diversity and bird evolution.

Key words: Avian evolution, Feather, Altricial, Precocial, Development.

Citation: Chen CK, Chuang HF, Wu SM, Li WH. 2019. Feather evolution from precocial to altricial birds. Zool Stud 58:24. doi:10.6620/ZS.2019.58-24.