ASU researchers discover chameleons use colorful language to communicate

December 11, 2013

To protect themselves, some animals rapidly change color when their environments change, but chameleons change colors in unusual ways when they interact with other chameleons. Arizona State University researchers have discovered that these color changes don’t happen “out-of-the-blue” – instead, they convey different types of information during important social interactions.

For example, when male chameleons challenge each other for territory or a female, their coloring becomes brighter and much more intense. Males that display brighter stripes when they are aggressive are more likely to approach their opponent, and those that achieve brighter head colors are more likely to win fights. Also, how quickly their heads change color is an important predictor of which chameleon will win a skirmish. Color changes in chameleons convey different types of information. Download Full Image

The results of the study are published online in the journal Biology Letters.

Russell Ligon, a doctoral candidate in ASU’s School of Life Sciences, and Kevin McGraw, an associate professor in the school, used photographic and mathematical modeling tools in new ways to study how the color change of veiled chameleons (Chameleon calyptratus) relates to aggressive behavior. They studied the distance, maximum brightness and speed of color change of 28 different patches across the chameleons' bodies.

“We found that the stripes, which are most apparent when chameleons display their bodies laterally to their opponents, predict the likelihood that a chameleon will follow up with an actual approach,” said Ligon. “In addition, head coloration – specifically brightness and speed of color change – predicted which lizard was going to win.”

Chameleons typically have resting colors that range from brown to green, with hints of yellow, but each chameleon has unique markings. During a contest, the lizards show bright yellows, oranges, greens and turquoises. Interestingly, when the chameleons showed off their stripes from a distance and followed that display with a “head-on” approach before combat, the important color signals on the striped parts of the body and head were accentuated.

“By using bright color signals and drastically changing their physical appearance, the chameleons’ bodies become almost like a billboard – the winner of a fight is often decided before they actually make physical contact,” Ligon said. “The winner is the one that causes its opponent to retreat. While sometimes they do engage in physical combat, these contests are very short – five to 15 seconds. More often than not, their color displays end the contest before they even get started.”

This is the first study of its kind. The research team took pictures of color standards and estimated the sensitivity of different photoreceptors in their cameras. Then, they used information on the physiology and sensitivity of the photoreceptors of chameleons and were able to measure the colors actually seen by the lizards. Though this method has previously been used to quantify static (unchanging) coloration, this study is the first to quantify rapid color change while incorporating the visual sensitivities of the animals under study.

There are approximately 160 species of chameleons in the world. Veiled chameleons are native to the Arabian Peninsula – specifically Yemen and Saudi Arabia. They are omnivorous and live essentially solitary lives, except when mating. Many chameleons are at great risk, as destruction of their habitats is occurring at alarming rates.

The study was funded by an ASU GPSA grant and by individual sponsors.

The School of Life Sciences is an academic unit of ASU’s College of Liberal Arts and Sciences.

Sandra Leander

Assistant Director of Media Relations, ASU Knowledge Enterprise


Workshop to explore influence of religion on scientific imagination

December 11, 2013

Where does the scientific imagination come from? What part does religion play? These and other questions will be the subject of a workshop on “The Transhumanist Imagination: Innovation, Secularization and Eschatology,” which will take place from noon-3:30 p.m., Dec. 13, in West Hall, room 135 on ASU’s Tempe campus.

The workshop will feature presentations by: Download Full Image

John Evans (UC-San Diego) on hope, progress and religious views of technology

Nassar Zakariya (NYU) on transhumanism, posthumanism and the theology of the secular

• Margo Lipstin (Harvard) and Ben Hurlbut (ASU) on Singularity University and technological messianism

What is transhumanism?

The term "transhumanism" denotes an ideology of extreme progress, suggesting a coherent narrative to account for the accelerated pace of science and technology. As a future-oriented outlook, transhumanism prophesizes scientific and technological advances for the well-being of humanity, enabling humans to live extremely long, intensely happy lives, free of pain and disease.

Transhumanism is more than an idle fantasy of a few techno-optimists; it is an eschatological narrative that draws together a range of religious and secular motifs around an ideology of innovation, intensifying an imagination of the future that foregrounds technology as the source of progress. The transhumanist posture toward innovation reaches well beyond the transhumanist community itself, exerting a powerful influence affecting innovation policies and practices, scientific and cultural views about the transformative powers of technology, as well as our understandings of human flourishing.

The eschatological vision of transhumanism has ethical and political ramifications: it is a radically individualist vision in which freedom is re-imagined as the agency to radically transform – and thereby transcend – the body. This understanding of freedom does not measure the present in terms of improvement over the past, but rather as an incremental progress toward a future in which transcendence is achieved by rendering the body utterly subordinate to the individual, creative will.

By examining the religious underpinning of the ostensibly secular transhumanist imagination, the workshop contributes to a larger discussion about the sources and dynamics of technological innovation in the current moment and the institutions being harnessed toward realizing the future that it imagines.

The workshop is organized by the ASU Center for the Study of Religion and Conflict, a research unit of the College of Liberal Arts and Sciences. The workshop is part of a larger project on The Transhumanist Imagination: Innovation, Secularization and Eschatology that is funded by a grant from The Historical Society’s program in Religion and Innovation in Human Affairs, and sponsored by the John Templeton Association.

ASU professors Hava Tirosh-Samuelson, of the School of Historical, Philosophical and Religious Studies, and Ben Hurlbut, of the School of Life Sciences, are the project directors.

For more information or to register, see or email