Baby Apes Shed Light on the Evolution of Laughter

http://www.findingdulcinea.com/news/science/2009/june/Baby-Apes-Shed-Light-on-the-Evolution-of-Laughter.html
Study Report: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VRT-4WFHK7G-5&_user=126524&_coverDate=06%2F04%2F2009&_rdoc=1&_fmt=full&_orig=search&_cdi=6243&_sort=d&_docanchor=&view=c&_acct=C000010360&_version=1&_urlVersion=0&_userid=126524&md5=7213143a34f92de5df75a55cfaec0e76#sec2

Continuing my primate-themed series of new & hots...

Laughter similarities among various types of primates supports evolutionary notion of a common ancestor. Researchers have been recording the tickle-induced giggles of various primates (humans included) and have discovered significant similarities among them. They draw several conclusions from mapping out the acoustics of the laughters and then comparing them. First, emotions originated from a common primate ancestor. Second, gorillas and bonobos possess the ability to control their breathing, one thought to be the key trait allowing humans to speak articulately.

I'm a little skeptical about the study. Exactly how many other species have researchers attempted to tickle and record their reactions? Primates, physically and genetically, are most resemblance to us so up and coming discoveries of new similarities between us and them hardly surprise me. Sometimes, I wonder if these primate-human-linking studies are conducted with the specific purpose to support evolutionary concepts. This follows a line of 'we are more closely related to monkeys than we thought" themed scientific studies. I would be more awed if similar discoveries were made in some species highly divergent from human beings.

Another question I have is exactly how laughing pertains to survival and natural/sexual selectivity. Or, if laughing only comes as a result of the ability to control breathing, does that mean that laughing is an unprecedented development or some sort of natural phenomenon? After reading the study report, I can understand the claim that laughing indicates a common primate ancestor, but I think I definitely need more data and argument before I can accept this recent discovery as evidence in favor of a full-out validity of evolution.

-Teresa