Primates at Arcadia

 

Week 5: Primates

Lecture

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Primates are any member of the group of animals that includes human beings, apes, and monkeys.

Apes are closely related to monkeys and humans, they are covered in hair and have no tail or a very short tail.

Monkeys are smaller, with tails. Some are prehensile and some are not.

There are two groups of monkeys:

Old World monkeys: baboons, macaques, colobus monkeys, among others

New World monkeys: spider monkeys, marmosets, howler monkeys, among others
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Most primates live in small groups. There are advantages to living in a group, including increased protection, shared parenting, and shared food supply.

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There are three main diets: carnivore (only eats meat), omnivore (eats meats and plants), and herbivore (eats only plants). Most primates eat fruits, which are high in energy, leaves, which are nutritious, and then some other foods they can find (like crickets!)

Activity 1

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Students play the meddling monkey scavenger hunt. This game

replicates the choices that primates make with regard to food

security, group safety, and survival. Students will be separated

into groups (each a different primate species) with a set number

of primate infants per group. The objective is to gather as many

calories as possible while protecting the infants in your group.

Scavenger hunt supplies:

  • Construction paper fruit (yellow and red) Value:  5 points
  • Construction paper leaves/stems (green) Value: 1 point
  • Construction paper insects (ants, grubs, and protein) Value: 3 points
  • Construction paper primate infants. Value: 10 points

Game Rules: 

  • Search the “forest” (classroom) to find as many calories as you can and bring them back to the troop.
  • Primates can only carry one food item since they are not bipedal.
  • Students can steal food that is unguarded. They can also steal unguarded infant primates.
  • To be protected from stealing food or infants, two people must be at the “home base.”
  • One person is not enough to protect it.
  • However, student groups can choose to leave as few or as many people at the nest as they wish.
  • At the end of the time, groups will reunite and scores will be added up.
  • A group automatically loses if all of their infants are stolen.

Videos of primate activity: Arcadia & arcadia2

 

Activity 2

EATING CRICKETS AND MEAL WORMS!!! Store bought insects were given to students who wanted to try them. Every single student did!

Video of students eating crickets and meal worms: Arcadia3

Ending Thoughts

I was so proud of my students for being so willing to try the crickets and meal worms. Several students mentioned they took this partnership class simply because they heard about this activity. Students in other classes found out we had these ‘snacks’ and joined in the activity! I hope this results in an even larger class next semester.

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Week 8: Comparative Osteology

Physical anthropologists rely on osteology, or the scientific study of bones, to identify individual species, learn about the lives of an individual, or even to identify ancient illnesses (aka paleopathology). The skeletal features of bones reflect the life histories of individuals, and trained osteologists can use those features to identify the age, sex, diet, and, at times, even the cause of death of a particular specimen.

However, analyzing and comparing the bones from different species can also tell us about the evolutionary history of those species and the degree to which different species are related. For example, the overall form and organization of a dog’s skeletal features would be very similar to those of wolves, as those species are related. The same could be said for different species of fish, reptiles, turtles, etc.

In anthropology, osteologists often compare human skeletons with those of other primates so that we can learn about our ancient human past. In today’s activity, our TMSE students compared cranial features of human, chimpanzee, and coyote skulls, to learn about cranial capacity, dental formulas, diet, and the overall degree of similarity among species. For this activity, students were encouraged to think about the similarities and differences between each of the individual specimens. If they are similar, what makes them similar? If they are different, then how could we explain those differences in an evolutionary context?

To begin with, the students compared the skeletal characteristics of human, chimpanzee, and coyote skulls. Students were able to identify the human skull and distinguish it from the chimpanzee skull rather quickly, but additional analysis was needed to characterize precisely why the students thought they were so different.

skulls

The human chimpanzee skulls differed, for example, in the size of the teeth, the size of the cranium, and even the shape of the skull itself. Students also learned a new term, prognathism, to describe the degree to which the facial features extend out from the face. Chimpanzees are definitely more prognathic than humans, as are coyotes. However, the human and chimpanzee skulls were more similar to each other than they were to the coyote, which had a completely different structure.

 

In seeking a better way to describe the possible differences and similarities, we then analyzed two key features on each skull: teeth and cranial size.

To analyze the similarity in dentition, students were asked to come up with the dental formula for each specimen. A dental formula is essentially a count of the different types of teeth for a specimen, beginning with incisors (cutting teeth in the front of the mouth), canines (teeth for slashing), premolars (for stabilizing food and for grinding); and molars (grinders).

teeth

By counting the tooth types for the human, chimpanzee, and coyote skulls, our TMSE students figured out that humans and chimpanzees have the exact same dental formula! However, coyotes have a different formula.

Our students quickly ascertained that this similarity is likely due to the fact that humans and chimpanzees are related, both as primates and by our shared evolutionary past.

 

To continue to address some of these differences, we then compared the size of the cavity that houses the brain, also known as the cranial capacity.

cranial

By comparing across species, our students figured out that humans have the largest brain, followed by the chimpanzee, and then the coyote. After a lively discussion of the brain size of dolphins, humans, dinosaurs, and dogs, we reached the conclusion that our human brains are MASSIVE relative to our body size. Which, of course, means that we are intelligent creatures.

Our comparative analysis led us to hypothesize that the dental formula and cranial capacity may help determine whether a particular specimen is related to humans or not. To test out our theory, we then threw an unknown skull into the mix. After figuring out the dental formula, describing the tooth size, and looking at the cranial characteristics, our students concluded that the unknown skull was, in fact, related to humans because it shared a dental formula and had a cranial capacity that was in between that of the human and of the chimpanzees.

As it turns out, our students were absolutely correct! The unknown skull was Australopithecus afarensis, one of our evolutionary ancestors.

This activity ended up being a lot of fun, as everyone got a chance to handle castes of skulls and learn about how physical anthropologists may characterize skeletons. Moreover, by learning about basic skeletal features and interspecies variation, our students were able to conduct a comparative analysis of those features and to critically analyze the results based on that analysis.

All in all, a great day!

 

The lesson plan for this activity can be downloaded here.

Week 8 Skeletal Features

Week 5: Meddling Monkeys Scavenger Hunt

One of the ways that physical anthropologists learn about people is to study our nearest living relatives – primates. Primates include any member of the group of animals that includes human beings, apes, and monkeys. Learning about how primates navigate their world helps us understand the challenges and survival strategies that humans had to face in the past.

Primatologists, or specialists who study primates, are especially interested in learning how primates address one of the biggest issues that we all face: how to feed your family. Each primate species has a different from of social organization, although all primate species have to figure out how to survive against the odds. Factors that figure in to those odds include the proximity of other groups, competition for resources, the availability of high-calorie foods, and the need to protect the sensitive members of one’s group from predators.

This week’s activity pitted student groups against each other in a Meddling Monkeys Scavenger Hunt. In the MMSH, student groups were tasked with getting as many calories as possible by “foraging” throughout the classroom. Foods were represented by different colors of slips of paper and were placed with varying frequency throughout the classroom. The highest calorie foods, fruits, were worth 5 points. Fruits were present but were not the most common type of food in the scavenger hunt. Animal protein accounted for another category of the food in the scavenger hunt, being worth 2 points. Common sources include ants, insects, or grubs. The most common food source in the scavenger hunt, and in actual environments, included leaves and vegetation. In the game, a cluster of leaves was worth 1 point.

Students were divided into groups and were asked to come up with a survival strategy that permitted them to gather the most calories while still protecting the two primate babies that were given to each group. These babies were worth 10 points and could be stolen if the nest was not properly guarded. At the end, the group with the most calories (points) won.

 

Rules:

Students can only carry one item at a time, as primates are not bipedal (except humans).

Students were asked to walk in various ways to lengthen the game, including hopping on one foot, knuckle-walking, crab-walking, and walking with their hands behind their back.

Babies can be stolen if not guarded. Two group members must be at the nest to protect the babies (not one).

If a group loses both of their babies, the group automatically loses.

 

At the end of the class period, the scores were tallied and each group was asked to weigh their choices against their relative success. Interestingly, only one group was able to steal a baby. And while such an acquisition may seem to signal success, a different group ended up with the highest number of points (or calories). That suggests that the most effective strategy for success may be more complex that focusing on a single, high-calorie resource.

At the end of the day, our class also got to try one of the delicacies of the primate diet – roasted crickets!

Here are a few of the brave TMSE students who elected to give our crickets a try!

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Others were more reluctant, but most of our students were willing to give it a shot.

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In the end, our  TMSE students learned about foraging strategies, the benefits of group membership, and even some of the downsides of being social. AND they got to sample a tasty treat!

Check back in next week, as we will start talking about human variation and genetic variability.