Life as We Know It
Dog faces, the history of laughter, snakes, and bird warning calls
- By Joseph Caputo, T.A. Frail, Megan Gambino, Ashley Luthern and Abigail Tucker
- Smithsonian magazine, August 2009
(Miriam Wessels / AP Images)
When did laughing begin? To find out, researchers led by the University of Portsmouth in England tickled young humans, chimps, bonobos, orangutans and gorillas. The sounds that these great apes made were so similar, the study concluded, the "origins of human laughter can be traced back at least 10 to 16 million years"—to our common ancestor.
Learn more about great apes at the Encyclopedia of Life.
"The mechanics of slithering locomotion," David L. Hu et al., PNAS, June 8, 2009.
"New nitrogen uptake strategy: specialized snow roots," Vladimir G. Onipchenko et al., Ecology Letters, June 4, 2009.
"Disambiguating the 'guilty look': Salient prompts to a familiar dog behaviour," Alexandra Horowitz, Behavioural Processes, July 2009.
"Mobbing calls signal predator category in a kin group-living bird species," Michael Griesser, Proceedings of the Royal Society B, May 27, 2009.
"Reconstructing the Evolution of Laughter in Great Apes and Humans," Marina Davila Ross et al., Current Biology, June 4, 2009.