Summer is a trying time for me. Many people take the time to relax, do things they couldn’t during the academic year. I do that, but I also get really restless. I try to do all that relaxing or different stuff at the same time, which just overwhelms me. I even have a hard time focusing on working on the dissertation (australopithecine growth and development; more on that in future post, promise). The academic year forces upon me a self-discipline whose bonds I break to become a directionless, scatterbrain piece of crap once summer begins. Although, I have been running a ton.
Tomorrow I head out the Republic of Georgia, where I’ll be helping at the Dmanisi Paleoanthropology Field School. The site is pretty important for human origins. It is the earliest hominid site outside of Africa (~1.77 million years ago), and so helps document the earliest periods when humans first became a colonizing species. There are a number of fairly complete skulls and a few partial skeletons. What we see in the cranial and mandibular remains is a great deal of morphological variation; however, it is very possible that this fossil assemblage samples a single population. This is important to take into account since many anthropologists are quick to use subtle variations to argue for the presence of multiple species. Also, researchers from a number of countries have come together to work at this exciting site.
Perusing my AJPA RSS feed, I came across an interesting abstract (see attempt at citation below). This article tests three different hypotheses for cranial robusticity in modern humans: genetic, mastication, and climate, and finds that mastication doesn’t seem to explain the robusticity of some populations. I didn’t read the article, just the abstract (it’s summer, and I was perusing), but it got me thinking. If we find population variation that is not based on climate or diet within modern humans, could this have been the case in more ancient hominids? My memory for australopithecine crania is terrible, but I keep thinking of all the different sized “erectines” and “habilines” we looked at in 565 – that sample definitely represented different levels of robusticity. I’m not really sure where I’m going with this (I probably should have read the article and thought about it for a day or so to collect my thoughts, but I’m impatient and felt like posting). I guess I’m just trying to link what we know about modern humans to what we think we know about other hominids. Thoughts? Did anyone else look at this article? Did you find it interesting or dull or poorly written or irrelevant? Is everyone having a good summer so far?
Baab et al. (2009) Relationship of Cranial Robusticity to Cranial Form, Geography and Climate in Homo sapiens. American Journal of Physical Anthropology – June 25.
I’ve been pretty busy since classes let out, so it’s been a while since I’ve posted anything. Two years of grad school down, n more to go. Hopefully no more than four more….
In a few hours, I leave lovely Ann Arbor, MI for my summer research, to the Transvaal Museum in Pretoria, South Africa. So far as I can tell, this museum has good collections of cultural artifacts, recent mammals, and tons of fossils. Many hominin remains are curated here as well, namely Australopithecus from the region–A. africanus from Sterkfontein and Makapansgat, and A. robustus from Swartkrans, Kromdraai, and I think also maybe Cooper’s Cave(?).
I’ll be focusing on the A. robustus collection. As with many fossil groups, the sample is largely teeth, and most other cranial remains are highly fragmentary–there are only a few relatively complete crania (including a remarkably well preserved skull, DNH 7 from Drimolen, which I don’t think is at the Transvaal and that I doubt I’ll get to examine. Oh well). The main project will examine the relative independence of many of the cranial, facial, and dental features in A. robustus, since these have been important in debates about whether the A. robustus and A. boisei (the latter from E. Africa) are more closely related to one another than to other hominins. Basically I’m going to test a few developmental/functional models that have been proposed, by applying a resampling procedure (that I’m still sort of in the process of developing). Hopefully it will be an interesting (and successful…) way of examining morphological integration in a fossil sample.
There are a few other projects, but this is the one I’m most interested in. I’ll do my best to keep Lawnchair readers (whoever they might be) updated. Here’s to what I hope will be a productive summer!
As Caroline noted, I have been Missing In Action for a while. So I’m sure the people who read the blog but aren’t in my program (so what, like 1.5 people?) are curious as to where I’ve been and what I’ve been doing.
To begin, I spent the first half of summer here in lovely Ann Arbor, working as a research assistant at UM’s Transportation Research Institute (UMTRI) in the biosciences division. There I basically did the tedious work cleaning up and prepping data so that my boss could analyze them. Mostly I digitized pelves and landmarks from CT scans, which was cool at first but got old pretty fast. Then I had to clean up these laser scans of bodies, which was even more boring than pelvis digitization. Then I left at the beginning of July, and I’ll start working there again today or tomorrow. Though a bit boring, the job provided a good introduction to modern methods, and I got paid a graduate student wage for doing work a competent undergrad could do. So I’m not going to complain too much.
So I left in July to attend a geometric morphometrics (GMM) summer school (that was 4 days long) hosted by the University of Vienna and the European Virtual Anthropology Network (EVAN). Geometric morphometrics is basically just a fancy way of saying ‘quantification and statistical study of shapes.’ Though the field has been developing since the 1970s with the work of Kendall on the distribution of archaeological sites, this methodology has become quite refined and very popular in recent years among biologists. Using the coordinates of landmarks (the most popular of which tend to be intersections of bony sutures on a cranium, for example) as individual variables, shapes (again, often of crania) can be summarized by numbers and subject to statistical analyses. A lot of interesting biological information can be discovered from shapes (say, of crania and their parts, of bee wings, etc.), and GMM preserves all shape data, much of which is can be less well preserved from more traditional morphometric methods (like using just distance ratios and angles).
I was sent there to work on a reconstruction project (of a famous fossil), which I have alluded to in previous posts. After I finished molding and casting the various bones of the cranium I was intending to reconstruct, I started looking into GMM as a means of reconstructing the cranium, using a fairly complete specimen of the same species as a reference. My advisor contacted the Viennese and EVAN for advice, and they ended up bringing me to Vienna to learn some methods and discuss collaborating on the reconstruction. But here’s the rub: my advisor did not tell them which fossil we intended to reconstruct, for fear that they might simply take the idea and do it more quickly than I could. So once I was out there I had to talk to their people about the logistics of the project, and which specimen we would reconstruct would, of course, be revealed. At lunch I went over the basic idea—what specimen we’d be reconstructing, which one we’d use as the reference, etc—and there was a brief silence. Their guy was smiling and kind of chuckled and said (paraphrase), “Well, that sounds like a good project. But we have a conflict of interest, because we’re already planning on reconstructing that specimen to do some biomechanical study. We are already working with one group in America and have a grant for it. We’ve been planning this for a few years.” I definitely was not expecting this.
At which point I maintained a cool façade, but was in fact so freaked out that I was crapping not just my own pants, but everyone’s pants in the whole restaurant. EVAN has paid for me to fly out to them, for my accommodations and course fees, and even for me to attend their other activities, under the condition that we collaborate on this project that I can’t do with them anymore. But their guy (let’s call him GW) is very nice about it. He is smiling and tells me we’ll have to come up with a new project on which to collaborate. He even paid for lunch, even though I had wanted to take him to lunch. For about a day and half after this conversation I was freaking out pretty badly, scrambling to come up with a new, interesting research question that could be addressed with GMM, so that their bringing me to Vienna was not a complete waste of a lot of money. Then I came up with an idea that I thought was pretty interesting, GW said it was interesting when I presented it to him, and so I think things might work out. Now I need to start talking to my advisor about the new project and get in contact with GW and EVAN so that we can start collaborating. Hopefully everything will work out this time.
I learned some very important lessons from this whole experience, starting with the reconstruction. I initially began this project last January, beginning with the molding and casting and not worrying about the actual analytical methods involved in the reconstruction. It was hard to work the molding and casting at the museum into my busy schedule, so of course I wasn’t done with the project by the end of the semester, when I’d intended to be done. So that’s the first lesson, as Milford put it (paraphrase), “Almost everything takes longer than you initially plan.” Lesson number two comes from the fact that the fabric of my plan completely unraveled basically at the very beginning, when all I did was tell GW my basic plan. Things fall apart, as Chinua Achebe wrote. Also, both Milford and GW have emphasized to me the paramount importance of having a good research question, and not simply to base your questions off of a method. But when I had to come up with a new project idea, I basically had to look for a question that could be answered with a specific method. But that’s not always a bad thing. When you’re fresh and green like I am, sometimes learning a method opens your eyes to the types of questions you can ask, and that’s what happened to me at the summer school (nevertheless, ideally the question should come first). Finally, the people from Vienna and EVAN were very nice, laid-back and intelligent, and I am really grateful to them for all I learned from them, about GMM and about life in general.
And after that hyper-intense week in the capital of the Eastern Empire, I spent the rest of the month in Croatia visiting my friend and peer Seki, examining some Bronze Age crania from Bosnia, trying to learn Croatian, and being awesome.
P.S. once I develop my new research idea and make sure it won’t blow up in my face like the last one I’ll post more about it.