ARCH 131 DAY 4 & 5.1

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Simon Fraser University *

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Anthropology

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Oct 30, 2023

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ARCH 131 DAY 4 & 5.1: Why Do Physical Anthropologists Study Primates? • Understanding Human Evolution : Humans are part of the primate order. By studying other living primates, physical anthropologists can gain insights into our own evolutionary history. • Studying Evolutionary Processes : By observing and researching primates, scientists can study various evolutionary processes in action, such as natural selection and sexual selection. These processes likely played a role in the emergence of humans. Classification of Life: • Domains of Life : Life is classified into three domains: Bacteria, Archaea, and Eukarya. • Animalia (Kingdom) : Within the domain Eukarya, the animal kingdom is one of the major groupings. This kingdom includes a wide variety of species, organized into various phyla. • Phyla of the Animal Kingdom : There are numerous phyla within the animal kingdom, encompassing a diverse array of species. For example, chordates are one of the phyla. • Chordata : Chordates are a phylum within the animal kingdom, characterized by certain features. Chordates are divided into several classes, each with its unique characteristics. • Classes of Chordata : Some classes within the phylum Chordata include Cephalochordata, Chonorichthyes, Agnatha, Aves, Osteichthyes, Reptiles, Mammalia, Amphibians, and Urochordata. • Infraclasses within Mammalia : The class Mammalia, which includes mammals, is further subdivided into infraclasses, one of which is Primata. • Eight Anatomical Primate Traits: • Grasping Hands with Opposable Digits : Primates have hands with opposable thumbs and fingers, allowing them to grasp objects. • Flattened Nails : Instead of claws, primates have flattened nails. • Forward-Facing Eyes with Stereoscopic Vision : • Arboreal Hypothesis : Some scientists have suggested that forward-facing eyes and stereoscopic vision in primates are adaptations for life in trees. • Visual Predation Hypothesis : Another hypothesis proposes that these visual traits are adaptations for capturing prey. • Generalized Body Plan : Primates exhibit a wide variety of body shapes and sizes, which is advantageous for adapting to different habitats.

• Various Locomotion Types : Primates display diverse locomotion patterns, including vertical clinging and leaping, arboreal quadrupedalism, brachiation (suspension), terrestrial quadrupedalism, and bipedalism. • Generalized Dentition : Primate teeth are bunodont, consisting of molars, canines, and incisors. • Reduced Olfactory Systems : Primates generally have a reduced sense of smell compared to other animals. They often rely more on their sense of vision. • Enclosed Bony Eye Orbits : Some primates have post-orbital bars or closures, which are bony structures surrounding the eyes. Brain Characteristics: Primates are known for their large brains relative to body size, which is a significant characteristic setting them apart from many other animals. This encephalization, or the development of a relatively large brain, has several implications: • Complex Cognitive Abilities : The large brain size in primates is associated with increased cognitive abilities, problem-solving skills, and adaptability. • Social Intelligence : It enables complex social interactions and group dynamics. Primates often engage in intricate social behaviors, and a larger brain capacity supports this. • Adaptation to Varied Environments : The enhanced brain size allows primates to adapt to various environmental conditions and ecological niches. • Longer Development Period : The evolution of larger brains has led to an extended ontogeny, meaning that young primates require a more extended period of growth and development to accommodate their complex neural systems. • Increased Information Processing : Larger brains allow for advanced sensory perception and information processing, vital for navigating complex environments. Life History Traits: • Single Offspring : Primates typically follow K-selected reproductive strategies, which involve producing fewer offspring with a higher investment in each individual. • Extended Ontogeny : Ontogeny refers to the developmental stages in the growth of an individual. Primates have extended ontogeny, meaning they go through a more prolonged period of growth and development. Behavioural Traits: Complex Sociality : Living in social groups provides various advantages, such as access to potential mates, cooperation in finding food, rearing young, defending against predators, and reducing the risk of becoming prey. This complex social behavior is a significant characteristic of primates.

Adaptive Radiation: • Definition : Adaptive radiation refers to the rapid speciation (divergent evolution) within a lineage, which results in the occupation of different ecological niches. This process usually follows significant changes in environmental circumstances. • Example 1 - Explosion of Flowering Plants : About 80 million years ago, an adaptive radiation occurred following the appearance of insect pollinators. This event was triggered by the extinction of dinosaurs. • Example 2 - Explosion of Mammal Diversity : Approximately 65 million years ago, following the extinction of dinosaurs, there was an explosion of mammal diversity. By 45 million years ago, mammal diversity had reached the levels seen today, with almost 5500 species belonging to 153 families in 29 different orders. • Example 3 - Primate Radiations : • 1st Radiation (Late Cretaceous, 80 – 65 mya): Appearance of the first primates from a common ancestor with slight divergence from an insectivore ancestor. Tooth shape indicates a broadening of the diet. • 2nd Radiation (Paleocene, 65 – 55 mya): Emergence of true primates with grasping hands, nails instead of claws, and increasing reliance on vision over smell. Two major groups: lemur-like and tarsier-like forms. • 3rd Radiation (Early or Mid-Eocene, 55 – 45 mya): Primitive monkeys appeared with increased arboreal quadrupedalism, larger brains, and greater reliance on vision. • 4th Radiation (Late Oligocene/Early Miocene, 30 – 20 mya): Split into two main groups, monkeys and primitive apes, with differences in diet and continued arboreal living. • 5th Radiation (Late Miocene, after 17 mya): Appearance of first true apes with terrestrial adaptations and a large, barrel-like torso. These apes had limbs designed for hand-over-hand climbing. Homologies, Analogies, and Convergent Evolution: • Homologies : Traits shared by different species due to a common ancestry. For example, the spinal cord in vertebrates. • Convergent Evolution : Different species with very different evolutionary lineages evolving similar traits. For example, insects, bats, and birds all evolving wings and flight independently.

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• Analogies (Analogous Traits) : Traits shared by different species that resulted from convergent or parallel evolution, evolved independently of each other. For instance, the wings and flight in insects, bats, and birds. Geological Timescale and Primate Distribution: • Pangaea : A supercontinent that existed about 250 million years ago. Over time, it broke apart into the continents we know today. • Major Climate and Geographic Changes : • 150 mya: Pangaea began to break up, leading to changes in continents' positions and climate. • 100 mya: Ongoing changes in continental positions and climate. • 65 mya: Dinosaurs disappeared, leading to significant ecological changes. • 60 mya: Continuation of climate changes. • 55 mya: Earth's continents and climate experienced further alterations. Major Trends in Primate Evolution : • Between 80 mya and 10 mya, five major stages in primate evolution have been identified. Each of these stages represents an adaptive radiation event within primate history. Miocene Primates (25 – 5 mya): • The Miocene epoch witnessed the emergence of early apes. • Ekembo (≈15 mya) : An early ape with forward-facing eyes, frugivorous dentition, and arboreal quadrupedalism. It still had some primitive characteristics, such as a long snout. • Dryopithecus (14 – 8 mya) : A chimpanzee-like ape that resembled living apes, with more advanced features like forward-facing eyes and larger brain size. It was also sexually dimorphic. • Sivapithecus (12 – 7 mya) : An orangutan-sized ape that inhabited woodlands, had large incisors and canines, and resembled modern orangutans. • Gigantopithecus (7.0 – 0.5 mya) : The largest primate ever, with dentition similar to Sivapithecus but significantly larger. Gigantopithecus was likely terrestrial. Modern Primate Taxonomy: Primates are classified into two suborders:

• Strepsirrhini (‘Prosimians’): This suborder includes two superfamilies: Lemurs and Lorises. • Haplorrhini: This suborder is further divided into two infraorders: Tarsiiformes (Tarsiers) and Anthropoidea (all monkeys, apes, and humans). • Parvorder Platyrrhini: New World monkeys • Parvorder Catarrhini: Old World monkeys, apes, and humans • Superfamily Cercopithecoidea: Old World monkeys • Superfamily Hominoidea: Apes and humans • Subfamily Homininae: This subfamily includes humans, chimps, bonobos, and some fossil species. Distribution of Primates: • Primates are distributed across the globe in different regions, primarily near the equator. • New World Monkeys : Primarily found in the Americas. • Old World Monkeys, Apes, and Prosimians : Distributed across Africa, Asia, and some parts of Arabia. Suborder Strepsirrhini (‘Prosimians’): The “Prosimians” Lemurs: • Characteristics include a dental comb and a "toilet claw" for grooming. • Lemurs are primarily found in Madagascar. Lorises: • These include Lorises, Pottos, Slender Lorises, and Galagos or Bush Babies. • They are found in Africa, Saudi Arabia, and India. Suborder Haplorrhini: Tarsiers, Monkeys, Apes, Humans Infraorder Anthropoidea: Monkeys and Apes Parvorder Platyrrhini: New World Monkeys • Characteristics: Small bodies, arboreal lifestyles, and three premolars. • Distribution: Found primarily in the Americas. • Superfamily Cercopithecoidea: This superfamily includes monkeys with various species. • Superfamily Hominoidea: This superfamily includes apes and humans. Parvorder Catarrhini: Old World Monkeys, Apes, Humans • Key Characteristics: Wide size range, greater sexual dimorphism, and ischial callosities.

• Distribution: Predominantly found in Africa, Asia, and parts of Europe. • Notable Groups: • Superfamily Cercopithecoidea: Comprises Old World monkeys, including vervet monkeys, talapoins, patas monkeys, guenons, macaques, mangebeys, baboons, mandrills, colobus monkeys, langurs, snub-nosed monkeys, and proboscis monkeys. • Superfamily Hominoidea: Comprises apes and humans, including lesser apes (gibbons) and great apes (orangutans, gorillas, chimpanzees, bonobos) in the family Hominidae. Subfamily Homininae: Great Apes and Humans • Notable members: Orangutans (Sumatran, Borneo, Tapanuli species), gorillas (Western Gorillas, Eastern Gorillas), chimpanzees, bonobos, and humans. • Human Origins: The Homininae subfamily includes humans and the closest relatives in the primate family tree. • Orangutans : Three species include the Sumatran, Borneo, and Tapanuli orangutans. • Gorillas : Western Gorillas (Lowland and Cross River) and Eastern Gorillas (Mountain and Eastern Lowland). • Chimpanzees : Two species of chimpanzees. • Bonobos : A separate species known for their unique social behaviors. • Humans : Part of the Homininae subfamily, humans represent one species within this group. Habitual’ or ‘Facultative’ Bipeds • Early hominins, part of the Homininae subfamily, are considered habitual bipeds. This means they regularly walked on two legs as their primary mode of locomotion. Nest Building • Some members of the Homininae subfamily, including great apes and humans, engage in nest building activities as part of their daily routines. Tool Use • Specific primates, such as chimpanzees, are known to use tools in various aspects of their lives. Dian Fossey • Dian Fossey was a renowned primatologist known for her extensive study and conservation efforts focused on mountain gorillas in Rwanda. Her work provided

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valuable insights into primate behavior and was highlighted in her book, "Gorillas in the Mist." Biruté Galdikas (SFU Archaeology Dept.) • Biruté Galdikas is another prominent primatologist who conducted extensive research on orangutans in Borneo. Her work contributed to our understanding of these great apes' behavior and ecology. Louis Leakey • Louis Leakey was a paleoanthropologist and archaeologist who played a significant role in the study of human evolution. He supported and mentored various primatologists, including Dian Fossey, Biruté Galdikas, and Jane Goodall. Jane Goodall • Jane Goodall is renowned for her groundbreaking research on wild chimpanzees in Gombe Stream National Park, Tanzania. Her long-term study provided crucial insights into chimpanzee social behavior, tool use, and communication. Modern Primatology • Modern primatology is the scientific study of primates, including their behavior, ecology, physiology, and conservation. It encompasses various research methods and approaches to understand primate species. Captive Studies • Captive studies involve observing and conducting experiments on primates living in controlled environments, such as zoos, sanctuaries, or research facilities. This controlled setting allows researchers to investigate specific aspects of primate behavior and cognition. Studying Primates • Researchers study primates in different settings, including captivity, semi-free-ranging conditions, and in the wild, to gain a comprehensive understanding of their behavior, social structures, and ecological interactions. Semi-Free-Ranging

• Semi-free-ranging studies involve primates living in enclosed, naturalistic environments that mimic their natural habitats. This approach offers a balance between controlled captivity and completely wild conditions. Field Studies • Field studies entail observing primates in their natural habitats, where they exhibit their natural behaviors. These studies provide valuable insights into primate social structures, feeding habits, and interactions with their environment. Part 1: Why Are Primates So Socially Complex? Primates exhibit complex social behaviors influenced by various factors, including reproduction, food, and protection from predators. 1. Reproduction: Access to Mates • Reproductive asymmetry refers to the difference between male and female reproductive potential. Primate females have limited reproductive opportunities due to gestation periods, infant dependency, and single offspring births. This creates competition among males for access to females. 2. Accessing Food • Intra-group competition for food can shape primate social behavior. Some primates form matrilineal clusters, and food distribution patterns can influence group dynamics. 3. Avoiding Predators • Group size and the size of primates can impact their protection against predators. Smaller primates may form larger groups to enhance their safety, while larger primates may rely on their size as a defense mechanism. Part 2: Types of Non-Human Primate Societies Primate societies come in various forms, from solitary living to complex social systems. Primate Social Systems • Solitary living involves groups limited to no more than two adults and their offspring. Monogamy consists of a male and female bonded pair for an extended period. • Polygamy includes one-male polygyny, polyandry, and multi-male polygyny. Polygyny • One-Male Polygyny involves one male and multiple females within a group. Some males form bachelor groups outside of these groups. Infanticide can be a concern in this social structure.

• Multi-Male Polygyny results in a dominance hierarchy, with an alpha male at the top. Males compete for priority access to females, rather than exclusive access. Fission-Fusion Polygyny • In this system, small groups temporarily form and split apart repeatedly. Foraging parties illustrate this patchy and ever-changing food distribution pattern. Polyandry • Polyandry is characterized by a single female living with multiple males, and the reproductive strategies in this system are complex. Reproductive Strategies • Parental investment differs between males and females. Dominance hierarchies can affect social status and access to mates. Some social behaviors are adaptable and can change over time. Dominance and Reproductive Success • The relationship between dominance and reproductive success is complex, as it depends on various factors. Primate Social Behavior: The Soap Opera • Primate social behaviors can lead to entertaining and intriguing stories, such as the soap opera of gorillas in captivity, which includes relationships, births, and dramatic events. An Introduction to Early Fossil Hominin Sites in Africa Major Fossil Hominin Sites in Africa Africa is rich in hominin fossil sites that have provided essential insights into the history of human evolution. Sterkfontein, Kromdraai, and Swartkrans • These sites are part of the "Cradle of Humankind," a UNESCO World Heritage site in South Africa. They have yielded numerous hominin fossils and are known for their contributions to the understanding of early human ancestors. Malapa • Malapa is another significant fossil hominin site in South Africa, known for its discovery of a well-preserved Australopithecus sediba fossil. Taung • Taung is famous for the discovery of the Taung Child, an early hominin specimen that played a crucial role in the study of human evolution. South African Fossil Hominin Sites

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• These sites have contributed to our knowledge of early human ancestors in southern Africa and their evolutionary history. Dolinas • Dolinas are natural depressions in the landscape that have been sites for fossil discoveries and excavation. East African Rift Valley • The East African Rift Valley, with its eastern and western branches, is known for its significant fossil hominin sites. This region has played a vital role in our understanding of human evolution. Lake Turkana • Lake Turkana is a prominent location for fossil hominins, providing important insights into our early ancestors. Lake Victoria • Lake Victoria and its surroundings have also yielded important hominin fossils and archaeological discoveries. Lake Tanganyika • Lake Tanganyika, one of the African Great Lakes, has been the site of various fossil hominin findings. Early Fossil Hominin Sites in East Africa • East Africa is well-known for its numerous fossil hominin sites. These sites have contributed to the understanding of human evolution. Olduvai Gorge • Olduvai Gorge in northern Tanzania is famous for its contributions to the study of early hominins. It has provided a wealth of fossil and archaeological material. Laetoli • Laetoli, also in northern Tanzania, is renowned for its 3.7-million-year-old hominin footprints, providing direct evidence of early bipedalism. Koobi Fora • Located in northern Kenya near Lake Turkana, Koobi Fora is known for its fossil hominins and early stone tools dating back to approximately 3.3 million years ago. West Turkana • West Turkana is another area near Lake Turkana that has been a significant site for early human fossils. Hadar

• Hadar is a region in the Afar Depression of Ethiopia and is known for its fossil hominin discoveries, including the famous "Lucy." Kada Gona • Kada Gona, in the Afar Depression, has yielded stone tools dating to around 2.6 million years ago.