section 1: primates - ddamm.weebly.com€¦ · • include tarsiers, monkeys, and apes • tarsiers...
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Primates share several behavioral and biological characteristics,
which indicates that they evolved from a common ancestor.
Section 1: Primates
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?
PrimatesCopyright © McGraw-Hill Education
Review
• extinction
New
• opposable first digit
• binocular vision
• diurnal
• nocturnal
• arboreal
• anthropoid
• prehensile tail
• hominin
PrimatesCopyright © McGraw-Hill Education
Vocabulary
PrimatesCopyright © McGraw-Hill Education
Characteristics of Primates
• Humans, apes, monkeys, and lemurs belong to a group of mammals called
primates.
• Primates share traits such as high levels of manual dexterity, keen eyesight,
complex brains and behaviors.
PrimatesCopyright © McGraw-Hill Education
Characteristics of Primates
Manual dexterity
• Primates 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.
PrimatesCopyright © McGraw-Hill Education
Characteristics of Primates
Senses
• Rely more on vision, less on smell than many other mammals
• Primates have binocular vision, eyes with overlapping fields of vision.
• Greater depth perception
• Can judge relative distance and movement
PrimatesCopyright © McGraw-Hill Education
Characteristics of Primates
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.
PrimatesCopyright © McGraw-Hill Education
Characteristics of Primates
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.
PrimatesCopyright © McGraw-Hill Education
Characteristics of Primates
Complex brain and behaviors
• Primates 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.
PrimatesCopyright © McGraw-Hill Education
Characteristics of Primates
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
Primates
Characteristics of Primates
Reproductive rate
• Low reproductive rates combined with habitat loss has resulted in a large
number of endangered primate species.
Copyright © McGraw-Hill Education
PrimatesCopyright © McGraw-Hill Education
Primate Groups
• Primates are a large, diverse group of over 200 species.
• Most are arboreal, or tree-dwelling
• Primates are classified into two subgroups:
• Strepsirrhines: more primitive, “wet-nosed” primates
• Haplorhines: “dry-nosed” primates, include the anthropoids, large-
brained, diurnal monkeys and hominoids.
Visualizing Primates
Animation
FPO
Add link to animation from page 454 (Figure 3) here.
PrimatesCopyright © McGraw-Hill Education
PrimatesCopyright © McGraw-Hill Education
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.
PrimatesCopyright © McGraw-Hill Education
PrimatesCopyright © McGraw-Hill Education
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.
PrimatesCopyright © McGraw-Hill Education
PrimatesCopyright © McGraw-Hill Education
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.
PrimatesCopyright © McGraw-Hill Education
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
PrimatesCopyright © McGraw-Hill Education
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.
PrimatesCopyright © McGraw-Hill Education
Primate Evolution
Arboreal advantage
• Primates 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.
PrimatesCopyright © McGraw-Hill Education
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.
PrimatesCopyright © McGraw-Hill Education
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.
PrimatesCopyright © McGraw-Hill Education
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.
PrimatesCopyright © McGraw-Hill Education
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