Ecological factors are likely drivers of eye shape and colour pattern variations across anthropoid primates
Abstract
External eye appearance across primate species is diverse in shape and colouration, yet we still lack an explanation for the drivers of such diversity. Here we quantify substantial interspecific variation in eye shape and colouration across 77 primate species representing all extant genera of anthropoid primates. We reassess a series of hypotheses aiming to explain ocular variation in horizontal elongation and in colouration across species. Heavier body weight and terrestrial locomotion are associated with elongated eye outlines. Species living closer to the equator present more pigmented conjunctivae, suggesting photoprotective functions. Irises become bluer in species living further away from the equator, adding to existing literature supporting a circadian clock function for bluer irises. These results shift the current focus from communicative, to ecological factors in driving variation in external eye appearance in anthropoid primates. They also highlight the possibility that similar ecological factors contributed to selection for blue eyes in ancestral human populations living in northern latitudes.
Citation
Perea-García , J O , Ramarajan , K , Kret , M E , Hobaiter , C & Monteiro , A 2022 , ' Ecological factors are likely drivers of eye shape and colour pattern variations across anthropoid primates ' , Scientific Reports , vol. 12 , 17240 . https://doi.org/10.1038/s41598-022-20900-6
Publication
Scientific Reports
Status
Peer reviewed
ISSN
2045-2322Type
Journal article
Rights
Copyright © The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Description
Funding: This research was supported by the National Research Foundation (NRF) Singapore, under its CRP funding programme (NRF-CRP 20-2017-0001 Award). JOPG was supported by a PhD Scholarship from the Singapore International Graduate Award (SINGA). CH received funding from the European Union’s 8th Framework Programme, Horizon 2020, under Grant Agreement No. 802719.Collections
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