Feb 6, 2023 · AUSTIN, Texas — Long believed to be a uniquely human trait crucial for communication, visible white sclera — the “whites of the eye” — occur more commonly in chimpanzees and other mammals than previously reported, finds a new study from researchers at The University of Texas at Austin.

Here, we examine the prevalence and development of white sclera from photographs in the largest sample of wild chimpanzees studied to date (n = 230 individuals). We then explore the presence of white sclera in 70 zoo mammal species. 2. Methods. The Ngogo chimpanzees live in the center of Kibale National Park, Uganda.

Jun 21, 2021 · Here, we provide a comparative analysis of ocular pigmentation patterns in 15 species of hominoids (humans, great apes & gibbons) that show marked differences in social cognition and quantify scleral exposure at the genus level.

Mar 13, 2023 · Recently, Lee, along with a team of researchers, published data showing that enough chimpanzees have white sclera to make the characteristic more than just an anomaly among them.

The relative contrast between the sclera and iris in all 3 species is comparable, suggesting a perceptual mechanism to explain recent evidence that nonhuman great apes also rely on gaze as a social cue. Keywords: sclera, iris, eye, coloration, comparative morphology

Feb 6, 2023 · Long believed to be a uniquely human trait crucial for communication, visible white sclera—the "whites of the eye"—occur more commonly in chimpanzees and other mammals than previously reported,...

Compared to us, chimpanzees and other nonhuman great apes have sclerae that are much darker in color or at least not as uniformly white as human eyes. Some researchers believe that the white sclera of the human eye may have evolved to make it easier for other individuals to detect the direction of our gaze.

White sclera in humans amplifies gaze direction, whereas the all-dark eyes of apes are hypothesized to conceal gaze from others. This study examines WHR and SSI in humans (N = 13) and gorillas (N = 85) engaged in direct and averted gazes and introduces a qualitative assessment of sclera color to evaluate variations in sclera pigmentation.

Jun 21, 2021 · Here, we provide a comparative analysis of ocular pigmentation patterns in 15 species of hominoids (humans, great apes & gibbons) that show marked differences in social cognition and quantify...

May 1, 2022 · Although many eye features were similar between humans and other great apes, a key difference was that humans have uniformly white sclera which creates clear visibility of both the eye outline and iris—the two essential features …