Chapter 2, we are primates, the primate background. So, this chapter is very much focused on what's called biological or physical anthropology. And it's one of the four sub fields of our discipline with the other three being cultural anthropology, linguistic anthropology, and archaeology. So, biological anthropologists are very interested in human evolution. And one of the ways to study that is to look at other members of the primate order. So although humans are not descended from monkeys, we do share common ancestors with them. And these are features are some of what will be examined in this chapter. Um, also I am personally a cultural anthropologist. So I don't have a whole lot of information to add in this particular chapter. That will change once we get into the chapters on cultural anthropology where I will give you more information and examples from my own fieldwork. So why is it important to understand humans as primates? Well, it's to understand our place in the world, to make inferences about the conditions under which evolutionary changes occur. And that one is particularly interesting because anthropologists are very interested in the human past, but clearly we can't go back and observe humans evolving. But one of the things we can do is examine present- day non-human primates, for example, to see if they have particular biological or behavioral traits that humans have. And then that can give us some insight into when those traits evolved. or if it's a trait such as habitual bipedalism or the use of language, we can also examine the fact that non-human primates do not share those traits. So again, why did we evolve them while the others did not? Another reason it's important to understand humans as primates is to explain the various ways of adapting to environments biologically. So biologically really refers to any trait or behavior that we are born with, right? So it's both our physical bodies and our instincts. It does not refer to any behaviors that are learned. And we'll look at why not a little bit later. Additionally, it's important to see how various primates adapt to similar circumstances in different ways behaviorally. So, this can give us some insight into human evolution. Uh but we have to be really careful in noting that the vast majority of non-human primate behavior is instinctive with some learning whereas for humans it's the opposite. Virtually everything we do is learned with almost nothing being instinctive. Non-human primates also provide models of how early humans may have lived. So we can examine some behavioral patterns such as we know that when chimpanzees reach sexual maturity, the females move away from the groups where they were born, whereas the males continue to live in the groups where they were born. This is most likely a way to avoid consangious mings. Meaning, it's a way for the females to avoid accidentally mating with their father or brother, right? It can't happen if they're living in a different group from their father or brother. So, that can give us some insight into how humans developed various rules guiding marriages. For example, primates can also provide models for understanding how human culture, including language and tool use, may have evolved. So, we know that today humans have language, which is an open communication system, meaning that we can express an infinite variety of new ideas. Um, obviously the tools we use are quite complicated. Most of you are watching this on a laptop or perhaps a tablet. Uh we know that the non-human primates sometimes use tools like water for rinsing off food, but they very rarely make tools. Uh, one of the only known exceptions are chimpanzees making termite sticks where they basically just pull the leaves and twigs off of a tree branch. Uh, they dip it into a termite mound, pull out the termites, and eat them. That may sound very basic, but that counts as making an artifact or tool because it was intentionally modified for a specific purpose. So again um examining chimpanzees making these termite sticks is interesting uh because it can give us some insight into how our ancestors began making tools and also the fact that we know it's not instinctive because some groups of chimpanzees make termite sticks whereas others do not. Um if it was an instinctive behavior we would expect to see all chimpanzees doing this. The fact that only some do this indicates that one chimpanzeee invented this along the way and then showed others how to do it. Right? So we see the beginnings of learned behaviors. A knowledge of primates is useful to other areas of inquiry including evolutionary biology. So again something like how do we develop habitual bipedalism? uh knowledge of primates is important for sustainability as primates are integral to many natural ecosystems. So many biological anthropologists today work in the field of conservation studies examining what do primates need in order to survive and thrive and how can we provide them with their needs. An understanding of primates is also important for understanding issues related to diet. We know that primates overall are omnivorous, meaning that we eat meat, plants, sometimes insects, all kinds of things, right? That's quite different from other mammals where if you think about wolves for example, they have very sharp teeth for tearing meat because they're carnivorous, but then they can't really make use of plant foods in the environment. Um, same for herbivores, right? That they have these very square blunt teeth for eating vegetation. Think of something like deer or cows, but then they can't really utilize any meat that's in the environment. So overall, both human and non-human primates are omnivorous, meaning that we can eat a variety of different foods. Understanding primates is important for aiding the rehabilitation of non-human primates that have been removed from their natural environments. This may be for reasons of human entertainment such as placing them in zoos or circuses or it may be for their use in scientific studies. But overall now there's an increasing recognition that because primates are all social animals um just as humans are, it's cruel to keep them without a social group. So that's one reason that when possible, anthropologists now promote placing primates back into their natural environments. It's also important to understand primates for aiding their protection and conservation. So again, issues like making sure that they have enough habitat, that they have the foods they need, enough space in order to survive and thrive. in understanding primates is important for being able to critically evaluate popular pseudocientific and anti-scientific ideas about humans, other primates in the past. Um, and this is a reference to Bigfoot who is mentioned in your textbook, right? Um, so basically Bigfoot is a pseudocientific idea in that there are reported sightings uh, but nothing that has ever been confirmed with scientific evidence. So we know that all non-human primates other than orangutans live in social groups. Therefore, um if there was a large ape living in North America, meaning Bigfoot, uh we would expect that most sightings of it would be in social groups, but that's not what's reported. Um the vast majority of Bigfoot sightings take place at night and they are of a single individual. That goes against what we know about primates which is that virtually all species are deol meaning active during the day and all species other than orangutans live in social groups. So we should expect to see Bigfoot in social groups not alone. So, the fact that most Bigfoot sightings uh don't conform to what we would expect of primates helps us to evaluate the fact that they are perhaps not real. Okay, here is a chart with a primate taxonomy just so you can see how we're all related to each other. Note that humans are there on the bottom right corner. So here is a list of primate characteristics. Primates are an order within mammals and some of our distinguishing characteristics are prehensil hands and feet. That means we are able to grasp with our hands. This applies to all species of primates. Humans are really the only species that does not have grasping feet to any extent. um the others do. Almost all of us primates have nails instead of claws. All of us have forward- facing eyes with stereoscopic vision, meaning 3D vision. And then that's used differently depending on the species. Monkeys may use it while brachiating through the trees. Uh humans may use it while hunting or playing sports, for example, or even driving a car. But overall, we all have those forward-facing eyes. Our most important shared trait is a large brain, both in actual size and relative to the rest of the body. It's our large brain that allows for the complex social behaviors of all primates, as well as the development of human culture, which refers to behaviors that are learned, taught, and passed down in groups. All primates generally have a single offspring. There are a few exceptions such as pygmy marmicetses will usually have twins. Uh one out of every 250 human births involves twins but overall single offspring are more usual. Whereas compare that with other mammals that often give birth to litters. We have a long period of infant dependency because infants have to develop not just biologically but they have to do a lot of learning. Obviously more so for humans versus non-human primates but all of them do some form of learning. Most species of primates are journal meaning that they are active during the day rather than the night. Uh many species of primates are aroreal, meaning that they live in trees where they move by brachiating through the trees, which refers to arm over arm swinging through the trees. Um humans are obviously the exception. Primates have a variety of ways of moving. uh quadripedal meaning on all fours, knuckle walking like what you might see chimpanzees doing, climbing, clinging, jumping, brachiating, but habitual bipedalism really belongs to humans only as well as our ancestors. All primates are social. Uh orangutans go through a period of life where they live alone. All other primates live in social groups and have non-specialized diets, meaning that we can take advantage of both vegetables and meat meats that are available in the environment. Okay. So if you look at the diagram on page 36 of your textbook, you'll note that the primate order is divided into two suborders, the strep serini and the hap laurini. Most of this chapter and subsequent information in the textbook will deal with hap lurini rather than strep serini. That's because as you can see from the chart, humans are members of Hap Larini and the other members of Haplerini are more closely related to us than the strip serini are. And therefore whether we're looking at physical physical characteristics or behavioral characteristics we're more likely to find good models for human evolution among the hap larine than among the strep serini. Okay. So again on page 36 of your textbook you'll notice on the chart that the hapllorion are divided into two infra orders the platini and the catini. And here you'll notice that the platini are the what are sometimes called new world monkeys because they are located in Central and South America. Whereas the cat teriy include what are sometimes called old world monkeys as well as the apes including humans. Um and here on this PowerPoint slide you see some of the differences between these two infra orders. So one of the interesting questions regarding the platini is how did their ancestors arrive in Central and South America? One of the hypotheses is that they rafted over from Africa. As strange as that may sound, we do know that primates made it hundreds of miles from Africa to the island of Madagascar, tens of millions of years ago, also presumably floating on rafts of natural vegetation. So it is possible uh today the distance from Africa to South America would be uh 1,800 miles. Uh but 40 million years ago, it was probably only about half that. So again, it's not impossible and we know they did get there somehow and none of the other hypotheses really have much evidence for them. So this is one of the interesting questions regarding non-human primates. [Music] So some of the key areas of interest in primatology meaning research on primates include communication such as vocalizations, gestures, displays and expressions. So keep in mind um that again there's a difference between the communication of non-human primates versus humans. Non-human primates have closed communication systems, meaning that they have specific calls for specific things such as predator or food. Whereas humans and quite likely our immediate ancestors have open communication systems, meaning that we can create an infinite variety of new terms and sentences to describe new things. Another interest in primatology is social structure, meaning how groups are formed, how dominance is achieved and maintained. So, for example, some species of non-human primates are roughly egalitarian with males and females being about equal. In others, the males dominate and in some the females dominate. And again, that is very different from humans in that for these non-human primates, it's extin it's instinctive, right? So these social structures are found in all groups of that particular species because they are based on instinct rather than culture. Another interest in primatology has to do with aggressive and affilative behaviors. So an one type of aggressive behavior would be conflict where uh various groups of monkeys may for example fight over territory. An example of an affiliative behavior would be grooming which removes parasites and dirt from the fur of individuals and also helps establish bonds of rapport. And we find this in many different species of non-human primates. uh subsistence and diet are of interest to primatologists and so is the use of tools. Right? So some well many monkeys use what are called echoacts meaning something natural that they find and they will use it as a tool. For example, rinsing sand off food by using water. in an artifact refers to something that has been consciously modified such as the termite sticks used by chimpanzees mentioned a bit earlier in this lecture. Okay. Here we see some examples of macaks using water as an echoact meaning that they are using it as a tool to rinse off food but they have not done anything to modify the water which is why it's not classified as an artifact. Compare that to humans uh where our use of water is almost exclusively an artifact in North America. Right? Uh virtually all of the water we use has been cleaned, piped into our homes through faucets and plumbing systems or it's been bottled in factories again after being thoroughly cleaned. So when humans use water, it's usually an artifact whereas when macaks use water, it's only an echoact. Okay. Here you see some cacotchins also using an echoact. They are opening ripe palm nuts by banging the shells open using two rocks. Right? So these are echoacts because the capuchins have not done anything to modify the rocks. However, they are using them as a tool for opening food. Here we see a chimpanzee, which by the way is an ape, not a monkey, holding an artifact. So this is a termite stick. The chimpanzee has pulled all the leaves and twigs off. That counts as intentional modification, and it's enough to turn the termite stick into an artifact rather than an echoact. The catarinai can be further divided into citheodia referring to oldw world monkeys and to hoia referring to apes and humans. And if it all seems somewhat confusing, please refer back to the chart on page 36 which shows how all these categories relate to each other. And here this PowerPoint slide shows you some of the key differences between these two super families. Here you see an orangutang. They are an example of hinoidia and they are unique among primates in that adult males spend large portions of their lives living alone. that is virtually unknown for all other species of primate which live in social groups. So that sort of shows you that for every rule we learn about primates um there will usually be at least one exception and this is very similar throughout all four subd disciplines of anthropology. Anytime you learn a rule, you will usually also learn that there are exceptions. This chart shows you the human taxonomy. So, we belong to a class called mammals that includes cats, dogs, bats, and rats. And really, what that is referring to is that we give birth to live offspring rather than, for example, laying eggs. and that these offspring are then nursed using breast milk. After that you see the order of primates which is the focus of this textbook chapter. It includes monkeys and apes. Um please note that monkeys are not apes and apes are not monkeys although the two do share common ancestors. After that we see the suborder hap rhiny referring to old and new world monkeys as well as apes. Then there's the infra order kata rhy referring to old world monkeys and apes. After that the super family may no including apes and humans such as chimpanzees, bonobos and gorillas. and the family of homi referring only to humans. Um today that means only homo sapiens but in the recent past it has also referred to other forms of humans such as Neandertols as well as homo hyalensus who is ancestral to both homo sapiens and neanderls. Before that there was homoagaster homo erectus and so forth. Right? So even though there is only one species of humans alive on the planet today, Homo sapiens, in the recent past, that was not the case. Throughout the vast majority of human history, there have been several species of humans on the planet at the same time, often coming into contact with one another. And we'll learn more about that as we progress throughout this course. Here you see an overview of primate evolution from 65 million years ago to the present day. So it starts out with the emergence of the very earliest primate ancestor around 65 million years ago. Shows you some of the key events. And please note the special importance of the pleaene 2.6 6 million years ago to 11,700 years ago when there were many species of humans on the planet. So homo rectus homoaster homohyalbergsis with homohygansis evolving into neanderls in ice age Europe and homo sapiens in Africa. Later these two species meet each other and have fertile offspring together. That is followed by the holosene when homo sapiens begins to not dominate. Neanderls depending on your view either go extinct or sort of join the homo sapiens population. But regardless of what eventually happens is that today we only have one species of human on the planet. That would be us homo sapiens. Now that we've learned about primate evolution, how different species of primate are related to each other, and what traits we all have in common with one another. It's also important to note that many species of non-human primate are in crisis today. There are several factors such as the destruction of primate habitats. So the kind of natural area they need for living has been decimated. Often what happens is that the habitat will get parcled out into smaller habitats because people will build something like cities or highways, cutting off one group of a species from other troops of that same species, making it impossible for them to find mates from a different area, for example, which can contribute to a lack of genetic diversity and is problematic. In some areas of the world, non-human primates are viewed as pests to be eradicated the way we North Americans might view spiders, for example, in our homes. So anam a specific example of that would be the II in Madagascar is often viewed as being bad luck. So local people will try to kill them. There's also an illicit trait in primates for pets in zoos. Many people think that baby monkeys in particular are really cute and they would make a fun exotic pet. But the reality is that because virtually all primates are social animals, they need to be living with other members of their species. that if they are kept alone in with just humans, they suffer emotionally and psychologically from that. Um, zoos have a similar problem. On one hand, they do good work in primate conservation and in educating the public about non-human primates in allowing us to see them up close. But it can be very challenging for zoos to have enough space to where they can have a sufficient number of a particular primate to where they can live in a what would be a normal grouping for that species and also to have enough space to engage in behaviors that are normal for that particular species. Um, the fourth one is probably less of a problem than the first three, which is that in some areas of the world, non-human primates are considered human food. Uh, but that is really quite rare and not nearly as concerning as the first three because it is on a much lower scale. So, thank you for listening to this chapter and this is the end of chapter 2.