Monday, November 21, 2005

Why Should I Have to Decide? I'm not even 45!

Every time I take courses in a new anthropological subdiscipline, I love it. I started with an infatuation with Archaeology, then fell head-over-heels for Social/Cultural Anthropology. Now, I'm only a couple of weeks away from completing my first Biological (formerly known as "Physical") Anthropology course, and I can't get enough.

ASM 104 has been as easy as its low number indicates, but I have hung on every word. I already knew the overview of the story of human origins, and we even covered it for a couple of weeks when I took ASB 222 (Buried Cities and Lost Tribes). I just wasn't prepared for how interesting it would actually be.

Paranthropus boisei
Every time Heather Smith (the instructor) would move to the next slide of her extremely organized class materials, I had more questions... questions that I'm sure she never expected to be answering in a 100-level course, although she had no problem doing so (she's a Ph.D. candidate at ASU in Biological Anthro).

I was sitting at a table during one of our lab sessions, looking at across at a skull of Paranthropus boisei (previously known as Astralopithecus boisei). I knew there was significant sexual dimorphism w.r.t. body size, yet the anterior teeth (incisors and canines) were not really any bigger than my own (this is true for P. boisei males and females).

Gorilla gorilla
I was wondering: How that could be? In extant (currently living) species of apes, not only were males much bigger than females, but the guys also posess very large canines. But here was a 2 million year old hominid where the males were much bigger in size, yet they lacked the large teeth for threatening (or attacking) other males.

(I think it is interesting to note that both P. boisei and G. gorilla are vegetarians. The enormous sagittal crest along the top of the their skulls was an anchor for the large temporal muscles needed for chewing fibrous plant stuff).

Recent hypotheses propose that this was an indication of monogamy in P. boisei-- that perhaps the males didn't have large incisors because they didn't need them for male-male competition over females because each male mated with a single female... "just like humans."

I immediately had felt like there were a couple of problems with this line of thinking. First and foremost, humans were not monogamous until very recently in our history. Nearly all documented human cultures in the past (and many still today) featured polygynous marriage patterns. Monogamy is a pretty recent idea for humans, and still far from universal.

Second, representatives of the Paranthropus genus thrived for a million years on this planet, and in spite of their small canines, males were significantly larger than females. Humans, on the other hand, show only slight dimorphism in comparison.

Oh boy... I'm getting pretty wordy here. Suffice it to say, I have another hypothesis to counter the "Paranthropus was just like us... monogamous" argument, but I'm keeping the details to myself until I can do some proper research and write something up. Yep, I'm working on an outside-of-class research project. See how totally consumed I am by this new thing?

I'm probably taking a Linguistics course next semester, so I can go crazy over my final anthro discipline.

No comments:

Post a Comment