Tag Archives: Anatomy

The Origin of the Human Smile

i-292d5241115b67e27ce78512e86d1926-chimp_smile.jpgA colleague and grad student of mine, Rob, just sent me the following question, slightly edited here:

A student in my intro class asked me a good question the other day to which I had no answer. When did smiling cease to be a threat gesture? I have a couple of ideas. One is that with reduced canines, smiling became a way to say “look, I have small canines, I am not a threat to you.” The other is that smiling is based more on a “fear-grin” than a threat. Under this idea, smiling might have been a way of showing deference to others. If everyone shows deference, it would be egalitarian, until the one guy comes along who never smiles. Maybe that’s why bosses often don’t smile. … let me know when you have some free time to have lunch. Tuesdays andWed’s probably work best for me.

Good question, and good ideas as to a possible answer. I have a couple of other ideas to contribute…. Continue reading The Origin of the Human Smile

The Potato and Human Evolution

ResearchBlogging.orgFallback foods are the foods that an organism eats when it can’t find the good stuff. It has been suggested that adaptive changes in fallback food strategies can leave a more distinct mark on the morphology of an organism, including in the fossil record, than changes in preferred food strategies. This assertion is based on work done by the Grants and others with Galapagos Island finches, by Richard Wrangham and me with hominids, and by Betsy Burr and me with rodents. Continue reading The Potato and Human Evolution

What did the immediate ancestor of chimps and humans look like?

Comparing living chimpanzees to living humans, in reference to the species that gave rise to these two closely related species, is one way to frame questions about the evolution of each species. Continue reading What did the immediate ancestor of chimps and humans look like?

The Buttocks is not an excretory organ

… but it might be a sexual organ…

The Federal Communications Commission has proposed a $1.4 million fine against 52 ABC Television Network stations over a 2003 broadcast of cop drama NYPD Blue….The fine is for a scene where a boy surprises a woman as she prepares to take a shower. The scene depicted “multiple, close-up views” of the woman’s “nude buttocks” according to an agency order issued late Friday….The agency said the show was indecent because “it depicts sexual organs and excretory organs , specifically an adult woman’s buttocks.”The agency rejected the network’s argument that “the buttocks are not a sexual organ.”[source]

Continue reading The Buttocks is not an excretory organ

Robert Full: Secrets of movement, from geckos and roaches

UC Berkeley biologist Robert Full shares his fascination with spiny cockroach legs that allow them to scuttle at full speed across loose mesh and gecko feet that have billions of nano-bristles to run straight up walls. His talk, complete with wonderful slow-mo video of cockroach, crab and gecko gaits, explains his goal of creating the perfect robotic “distributed foot.”

Continue reading Robert Full: Secrets of movement, from geckos and roaches

Pilobolus: A performance merging dance and biology

Pilobolus dance company members Otis Cook and Jennifer Macavinta perform the sensuous duet “Symbiosis.” Does it trace the birth of a human relationship, or the co-evolution of a pair of symbiotic species? That’s left for you to decide. Gorgeous, organic choreography blurs the boundaries between the two performers, who use the body’s own geometry to lift, move and combine. The music, recorded by the Kronos Quartet on Nonesuch Records, is a compilation of works: “God Music” from Black Angels by George Crumb, “Fratres” by Arvo Pärt, and “Morango … Almost a Tango” by Thomas Oboe Lee.

Continue reading Pilobolus: A performance merging dance and biology

The Flores Hominid and the Evolution of the Shoulder

Blogging on Peer-Reviewed Research

Homo floresiensis more widely known as the “Hobbit,” may have had arms that were very different from those of modern humans.

A paper in the current issue of the Journal of Human Evolution explores the anatomy of H. floresiensis. To explore this we first have to understand the concept of “Humeral torsion.” Humeral torsion is the orientation of the humeral head relative to the mediolateral axis of the distal articular surface. Don’t bother reading that sentence again, I’ll explain it.

Continue reading The Flores Hominid and the Evolution of the Shoulder

Cooking and Human Evolution

From Scientific American, a piece on the “Cooking Hypothesis” (which yours truly helped develop some years back).

Our hominid ancestors could never have eaten enough raw food to support our large, calorie-hungry brains, Richard Wrangham claims. The secret to our evolution, he says, is cooking

Cooking does indeed turn a lot of stuff that is not edible to humans (or any primate) into usable energy. We think the increase in body size that comes along with the genus Homo (with Homo erectus and kin) is itself a biological signal of cooking.

The problem with his idea: proof is slim that any human could control fire that far back. Other researchers believe cooking did not occur until perhaps only 500,000 years ago. Consistent signs of cooking came even later, when Neandertals were coping with an ice age. “They developed earth oven cookery,” says C. Loring Brace, an anthropologist at the University of Michigan at Ann Arbor. “And that only goes back a couple hundred thousand years.” He and others postulate that the introduction of energy-rich, softer animal products, not cooking, was what led to H. erectus’s bigger brain and smaller teeth.

Continue reading Cooking and Human Evolution