Over the course of the summer as my class and syllabus began to take shape, I had to consider the order in which I would teach the units in the course; I decided the best way to proceed was to begin with the origin of humanity and our non – human primate relatives. My reasoning was based simply on how I could best build a framework for humanity, so why not simply start near the beginning? The next step was deciding how to begin the unit: begin with hominids or begin with non – human primates. I decided as a means of demonstrating the importance of primate morphology that I should begin with primatology in order to focus on the specific traits that make monkeys and apes unique among mammals.
I began developing my students’ knowledge by covering content in which I felt they already had a relatively strong base: Evolution. I had the students read from the PBS Evolution Blog to simply review their knowledge and had them discuss a few basic concepts, such as inheritance, mutations, natural selection, and adaptation. For about half of a class period, we built their knowledge of evolutionary biology into the framework of primate development and then moved into the growth of mammals and primates starting from approximately 65 million years ago. In the few days afterward, we began to build their knowledge of primate evolution and the variations between prosimians, monkeys, and apes.
I created this unit with a few major learning goals in mind overall.
- Students can explain the common traits all primates share
- Students can explain arboreal theory as a means for explaining common primate traits
- Students can differentiate between monkeys, apes, and hominids
- Students can identify major primatologists and their contributions to Anthropology
- The Trimates
- Dian Fossey
- Jane Goodall
- Birute Galdikas
- Primate Symbology
- Francine Patterson
- Sue Savage – Rumbaugh
- Allen & Beatrix Gardner
- The Trimates
This simple outline created the structure necessary for the roughly two week unit. We started out with our discussion on evolution coming out the dinosaur extinction approximately 65 million years ago. The first primates appeared roughly 54 million years ago; these were the first versions of anthropoids were likely most similar to prosimians that we now see in Madagascar. Future evolutionary developments continued until the first hominoids appeared approximately 23 million years ago, although most of them lived in areas that are now North America and Europe. Over millennia they would transition away from these regions and into Central and South America, Africa, and Asia as both climate the the continents shifted. Some of the extinct species we discussed include:
- Gigantopithecus: The largest primate known up to now. Paleoanthropologists have only discovered jawbones of this genus.
- Pierolapithecus catalaunicus: Discovered in Spain back in 2004. It was most likely a hominoid.
- Sahelanthropus tchadensis: This was a primate discovered in Chad which had both arboreal & terrestrial traits. This is one of many potential missing links.
- Orrorin tugenensis: This was also discovered in Africa; it likely lived in a forested area, but was bipedal and appears to have had very good tree climbing skills, making it also a good example of the missing link.
We moved from this rudimentary introduction of primate evolution to modern primate morphology & primate behaviors. The major features that I thought were important for students to learn focused primarily on what traits hominids, monkeys, and apes shared that sets us apart from other mammals. We began with primate tendencies:
- Ecological Niches: These vary amongst all non – human primates.
- Most all monkeys and apes are diurnal, meaning that they stay awake during the day and sleep at night. This is likely an evolutionary adaptation to stay away from nocturnal predators.
- The majority of monkeys across the globe are also arboreal, meaning they spend the majority of their time in trees. This adaptation is important because of arboreal theory, the concept that humans evolved to life in the trees. I’ll discuss this a bit more in a moment.
- Despite the arboreal nature of monkeys, there are several, such as the baboon, that are terrestrial. African Great Apes are also terrestrial, as are our closer hominid ancestors. Orangutans, common in South and Southeast Asia, are primarily arboreal, however; unlike most other primate species, they are not gregarious.
- Diets also vary depending on ecological niches. Some are leaf eaters, others eat primarily fruit eaters. Chimpanzees have even been known to kill and eat monkeys and prosimians. This behavior appears to be unique to them amongst non – human primates, with the hunting of monkeys having a socio – political slant amongst groups.
- Interaction with the World: This feature matters because of common behavior amongst other mammals, such as canines and felines, from which primates depart significantly. It is these features that clearly differentiate all primates from other mammals.
- Primates have an opposable thumb that allows for a unique graping ability. This is one of the key features that arboreal theory can effectively explain. In order to adapt to life in the trees, primates needed the ability to more effectively grasp tree branches; babies also needed the ability to cling to their mothers in the first years of life.
- Primates also have binocular stereoscopic vision. This means that our eyes are forward facing and that each eye perceives the environment slightly differently which allows for highly improved depth perception. This is also good evidence for arboreal theory. Monkeys have to move through a treacherous environment high above the ground through branches that can be separated by several meters; this requires precise vision to jump from branch to branch without falling to their deaths.
- The key variation between primates and many other mammals is this interaction with the world via sight and touch rather than via smell. The olfactory bulbs of other mammals such as dogs, cats, sheep, and the like are fare more developed, while primates have far more developed occipital lobes.
- Primate Behavior: These are behaviors that are common amongst many, but not all, primates.
- Primates also have one of the most developed brains in the animal kingdom. While monkeys have not yet shown the ability to recognize themselves in mirrors, several great apes have demonstrated this ability. Moreover, the ability of apes and hominids to use tools appears to be unique, although other mammals have shown some ability to use them, as well.
- Most all monkeys and apes are also gregarious. They live in relatively large groups, coordinate with one another through politics and social organization, and create relationships that are not based solely on kinship. While there are some examples, such as orangutans, those are the exceptions that help to prove the rule.
- One final factor is parental investment. Hominids invest a tremendous amount of time in parenting compared to other mammals, primarily because of bipedalism and brain development. The great apes also have a tremendous amount of time in their children, as do most monkeys.
After discussing these basic concepts of primates and primate evolution, we delved into a few of the more interesting aspects of modern apes.
First, we discussed the Trimates and their contributions to Science. Jane Goodall is arguable the most famous of the three, having become a household name over the last several decades through both her research and her conservation efforts. The fundamental aspects of her research that we studied were focused primarily debunking on the perception of chimps as loving, carefree, dumb animals. She showed the scientific world that chimps could use tools, create alliances within groups, and even go to war over territory, supplies, and females.
Next we discussed Dian Fossey and her lamentable end. Our primary focus in regards to her work, however, was her tactics and methodology and how it varied from those of Jane Goodall. While I did use her research as a means to teach about gorillas, I also used her as a means to show strong methodological methods with her subjects. We also used her as a means to understand inappropriate methods for dealing with local populations, interns, and students.
Finally, we discussed Birute Galdikas, the least known and understood of the Trimates. Rather than focus heavily on research and publication as both Goodall and Fossey did, Galdikas has used most of her career to work toward conservation of Orangutans. We used her story to see the possibility of Anthropologists becoming advocates for their particular focus of research.
The final portion of this unit focused on primate symbology, specifically research done by Francine Patterson, Sue Savage – Rumbaugh, and Beatrix & Allen Gardner. For this unit, I used Professor Nathan H. Lents’ Human Evolution Blog. This specific post details the work of each of these scientists with Koko, Kanzi, and Washoe respectively. The post includes extensive information about each of the apes and includes selected videos about each, as well.
My students had a great response to this; it drove an interesting discussion on what using sign language by apes tells us about ape brain development, ape emotional development, and the possibilities & limitations in the relationship between researchers and their subjects.
I loved teaching this unit, mainly because I got to see light bulbs go off repeatedly in my classroom and invigorated learning on a daily basis.