Be honest now, what was your reaction when you saw the bonobo laughing? I'll bet a fiver to Oxfam that you smiled at least, or even laughed.
What you were doing was responding just the way you would if you saw a human laugh. You did this because we share laughter with all the living Great Apes, even our most distant relative, the Orangutan, and the vocalisation is close enough to ours to trigger the same empathetic response that would be triggered by human laughter.
Not only that, but how differently and similarly we laugh can be arranged in a phylogenetic tree which maps perfectly onto the well-established phylogenetic tree based on genetic similarities and differences. Laughter is a form of vocalisation from way before we evolved language.
The team analysed the acoustics of laughter recorded when tickling 21 juvenile apes including orangutan (Pongo pygmaeus), gorilla (Gorilla gorilla), chimpanzee (Pan troglodytes) and bonobo (Pan paniscus) and compared them to the laughter of human (Homo sapiens) infants being tickled by their mothers.
It has long been claimed that human emotional expressions, such as laughter, have evolved from nonhuman displays. The aim of the current study was to test this prediction by conducting acoustic and phylogenetic analyses based on the acoustics of tickle-induced vocalizations of orangutans, gorillas, chimpanzees, bonobos and humans. Results revealed both important similarities and differences among the various species’ vocalizations, with the phylogenetic tree reconstructed based on these acoustic data matching the well-established genetic relationships of great apes and humans. These outcomes provide evidence of a common phylogenetic origin of tickle-induced vocalizations in these taxa, which can therefore be termed “laughter” across all five species. Results are consistent with the claims of phylogenetic continuity of emotional expressions. Together with observations made on the use of laughter in great apes and humans, findings of this study further indicate that there were two main periods of selection-driven evolutionary change in laughter within the Hominidae, to a smaller degree, among the great apes and, most distinctively, after the separation of hominins from the last common ancestor with chimpanzees and bonobos.
Ross MD, Owren MJ, Zimmermann E. The evolution of laughter in great apes and humans. Communicative & Integrative Biology 2010;3(2):191-194.
Projecting these back in time shows that laughter evolved in the common ancestor we share with all the other apes some 16 million years ago.
So, creationists, next time you make us laugh with your idiotic fairy tales and inability to let facts interfere with your superstition, bear in mind that we evolved the ability to laugh at you millions of years ago, along with our close biological cousins, orangutans, gorillas, chimpanzees and out closest cousins of all, the bonobo.