Section 1: share several behavioral and biological characteristics, which indicates that they evolved from a common ancestor. K What I Know W What I Want to Find Out L What I Learned
Essential Questions What are the characteristics of primates? What are the similarities and differences between major primate groups? How can the evolution of primates be traced?
Vocabulary Review extinction New opposable first digit binocular vision diurnal nocturnal arboreal anthropoid prehensile tail hominin
Characteristics of Humans, apes, monkeys, and lemurs belong to a group of mammals called primates. share traits such as high levels of manual dexterity, keen eyesight, complex brains and behaviors.
Characteristics of Manual dexterity typically have five digits on each hand/foot. An opposable first digit, one that can brought across the palm or foot to touch other digits, is a unique primate feature.
Characteristics of Senses Rely more on vision, less on smell than many other mammals have binocular vision, eyes with overlapping fields of vision. Greater depth perception Can judge relative distance and movement
Characteristics of Senses Most primates are diurnal, or active during the day Diurnal primates have color vision, reduced sense of smell Some primates are nocturnal, or active at night Black and white vision Most primates have unspecialized teeth, suitable for a diverse diet.
Characteristics of Locomotion Flexible bodies, limber shoulders and hips Rely primarily on hind limbs for locomotion All primates except humans walk on all four limbs, but many can walk on two legs for limited distances.
Characteristics of Complex brain and behaviors have large brains for their body size. Less brain area devoted to smell, more to vision Many primates have problem-solving abilities and complex social behaviors.
Characteristics of Reproductive rate Compared to other mammals, primates: Have fewer offspring (usually one at a time) Have long pregnancies Have newborns with a longer period of maternal dependency
Characteristics of Reproductive rate Low reproductive rates combined with habitat loss has resulted in a large number of endangered primate species.
Primate Groups are a large, diverse group of over 200 species. Most are arboreal, or tree-dwelling are classified into two subgroups: Strepsirrhines: more primitive, wet-nosed primates Haplorhines: dry-nosed primates, include the anthropoids, largebrained, diurnal monkeys and hominoids.
Visualizing Animation FPO Add link to animation from page 454 (Figure 3) here.
Strepsirrhines Identifiable by their large eyes and ears Only primates that rely predominantly on smell for hunting/ social interaction Primarily found in Madagascar, some in SE Asia and Africa
Characteristics of Strepsirrhines Interactive Table FPO Add link to interactive table from page 455 (Table 1) here.
Haplorhines Include tarsiers, monkeys, and apes Tarsiers are found only in Borneo and the Philippines small, nocturnal, arboreal The anthropoids (monkeys and apes) are split into the New World monkeys, Old World monkeys, and apes.
Haplorhines New World monkeys The New World monkeys refer to the species found in the tropical forests of Mexico, Central America, and South America. Diurnal, arboreal, live together in social bands Distinguished by their prehensile tails a strong, fifth limb-like structure used for grasping and balance.
Haplorhines Old World monkeys Old World monkeys live throughout Asia and Africa forests, mountains, grasslands Diurnal and live in social groups None have prehensile tails, and some have no tails.
Haplorhines Apes Apes have longer arms than legs, barrel-shaped chests, no tails, and flexible wrists. Highly social and have complex vocalizations Classified into two subcategories: the lesser apes and the great apes
Haplorhines Apes Lesser apes: Arboreal, move through the trees using a hand-over-hand swinging motion called brachiation. Great apes: Largest primates, include gorillas, orangutans, chimpanzees, humans Humans are in a separate subcategory of hominids called hominins humanlike primates more closely related to modern humans than to the rest of the great apes.
Primate Evolution Arboreal advantage may have evolved from ground-dwelling animals that searched for food in the branches of forest shrubbery. Rise of flowering plants could have provided a new niche for primates to exploit.
Primate Evolution Primate ancestors Genetic data suggests the first primates lived ~85 mya. The earliest primate fossils appear in the fossil record ~60 mya, at the beginning of the Eocene epoch. Early primates were small, lemur-like, nocturnal animals that ate fruits and insects.
Primate Evolution Diverging primates 50 mya, lemur-like primates were widespread and existed on all continents except Australia and Antarctica. Around this time, arthropods began to diverge, and were widespread by 30-35 mya.
Primate Evolution Displacement By the end of the Eocene, many early strepsirrhines became extinct. Extinction could have been driven by geological/climatological factors, or by diversion of anthropoids Larger anthropoids with bigger brains could have outcompeted strepsirrhines. This is supported by modern observations where strepsirrhines and anthropoid habitats overlap.
Review Essential Questions What are the characteristics of primates? What are the similarities and differences between major primate groups? How can the evolution of primates be traced? Vocabulary opposable first digit binocular vision diurnal nocturnal arboreal anthropoid prehensile tail hominin