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PRIMATE EVOLUTION
ANTHROPOLOGY: CHAPTER 6
CULTURAL ANTHROPOLOGY: NOT PRESENT
PHYSICAL ANTHROPOLOGY AND ARCHAEOLOGY: CHAPTER 6
CHAPTER OBJECTIVES
1.
Be able to identify and distinguish between the Early Cenozoic primates and the
Oligocene anthropoids.
2.
Be able to identify and distinguish between the Miocene hominoid species.
3.
Understand the history of the concept of a “missing link” and why this idea has been
discredited.
CHAPTER OUTLINE
I. Chronology
A. The history of vertebrate life on earth is divided into three eras: Paleozoic; Mesozoic; and
Cenozoic.
1. Each era is divided into periods.
2. Each period is divided into epochs.
B. Anthropologists are concerned with the Cenozoic era, which includes two periods:
Tertiary and Quaternary.
1. The Tertiary period has five epochs: Paleocene; Eocene; Oligocene; Miocene; and
Pliocene.
a. A wide range of small mammals, some possibly ancestral to primates, appeared
during the Paleocene.
b. Prosimian-like fossils abound in strata dating to the Eocene.
c. The first anthropoid fossils date to the late Eocene and the early Oligocene.
d. Hominoids became widespread during the Miocene.
e. Hominids first appeared during the late Miocene or early Pliocene.
2. The Quaternary period has two epochs: Pleistocene and Holocene.
II. Early Primates
A. Arboreal theory
1. Primates became primates by adapting to life in trees.
2. Enhanced sight (depth perception)
3. Grasping hands and feet
B. Visual predation hypothesis (Cartmill 1972, 1992)
1. Binocular vision, grasping hands and feet, and reduced claws developed because they
facilitated the capture of insects.
2. Early primates first adapted to life in the bushy forest undergrowth and low tree
branches.
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C. Early Cenozoic Primates
1. The earliest primates date to the first part of the Cenozoic (65-54 m.y.a.).
2. The Eocene (54-38 m.y.a.) was the epoch of prosimians with at least 60 different
genera in two families.
a. The omomyid family lived in North America, Europe, and Asia and may be
ancestral to all anthropoids.
b. The adapid family was ancestral to the lemur-loris line.
3. Anthropoids branched off from the prosimians during the Eocene.
a. Anthropoid eyes are rotated more forward compared to prosimians.
b. Anthropoids have a fully enclosed bony eye socket.
c. Anthropoids have a dry nose separate from the upper lip.
d. Anthropoids have molar cusps.
D. Oligocene Anthropoids
1. During the Oligocene (38-23 m.y.a.), anthropoids were the most numerous primates.
2. The parapithecid family may be ancestral to the New World monkeys.
3. The propliopithecid family may be ancestral to Old World monkeys, apes, and
humans.
III. Miocene Hominoids
A. The earliest hominoid fossils date to the Miocene epoch (23-5 m.y.a.).
B. Proconsul
1. Proconsul was the most abundant anthropoid in the early Miocene.
2. Its teeth have similarities with modern apes, but below the neck the skeleton is more
monkey-like.
3. Their teeth suggest that they ate fruits and leaves.
4. Proconsul probably contained the last common ancestor shared by Old World
monkeys and the apes.
5. Monkeys replaced Proconsul in the late Miocene.
a. Monkeys probably were superior at eating leaves.
b. Monkey molars developed lophs, which enhanced their ability to chew leaves.
6. Traits
a. Primitive traits are those passed on unchanged from an ancestor.
b. Derived traits are those that develop in a particular taxon after a split from a
common ancestor.
C. Afropithecus and Kenyapithecus
1. Afropithecus is a large, slow-moving Miocene hominoid with large projecting front
teeth from northern Kenya (18-16 m.y.a.)
2. Recent research suggests that the two species of Kenyapithecus should be reclassified
as Equatorius.
3. Equatorius and Afropithecus are probable stem hominoids, species somewhere on the
evolutionary line near the origins of the modern ape group that are too primitive to be
considered direct ancestors of living apes and humans.
D. Sivapithecus
1. Sivapithecus belongs to the ramapithecid genera along with Gigantopithecus.
2. Sivapithecus is now believed to be ancestral to the modern orangutan.
E. Gigantopithecus
1. Gigantopithecus is the largest primate that ever lived, some standing over 10 feet tall
and weighing 1,200 pounds.
2. Since it died out around 400,000 years ago, it coexisted with Homo erectus.
3. Some people believe it is still alive today as the yeti and bigfoot.
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F. Dryopithecus
1. Dryopithecus lived in Europe during the middle and late Miocene.
2. This group probably includes the common ancestor of the lesser apes (gibbons and
siamangs) and the great apes.
3. Dryopithecus has the Y-5 arrangement of molar cusps typical of Dryopithecus and of
hominoids.
G. Oreopithecus
1. Oreopithecus bambolii lived between 9-7 m.y.a. and spent much of its time standing
upright and shuffling short distances.
2. Its big toe splayed out 90 degrees from the other toes.
IV. A Missing Link?
A. Kottak refers to the last ancestral population held commonly by humans, gorillas, and
chimpanzees as Hogopans (after the genus names of these three).
B. The lines of the orangutans, gibbons, and siamangs split off several million years earlier.
The hominid line almost certainly diverged from those of chimps and gorillas late in the
Miocene epoch, between 7 and 5 m.y.a.
C. Hogopans probably split into the three separate lines leading to gorillas, chimpanzees, and
humans no more than 8 m.y.a., with each group moving into separate niches: equatorial
forest-dwelling and eating bulk vegetation (gorilla), Central African woodland-dwelling
frugivores (chimpanzee), and open grassland (hominids).
V. Beyond the Classroom: Maceration of a Canadian Lynx
A. Barbara Hewitt studied how the condition of a lynx’s bones reflected its former health.
B. After preparing the skeleton, Hewitt was able to identify pathologies in the animal’s
bones.
LECTURE TOPICS
1.
Discuss the patterns of hominoid evolution during the Miocene.
2.
Discuss the relationship between the advancement of thought and worldview. Use the
example of the Great Chain of Being as your starting point.
SUGGESTED FILMS
Ancient Mysteries: Bigfoot
1994 50 minutes
Narrated by Leonard Nimoy, this film traces reports of Bigfoot sightings over thousands of years
and discusses the current state of Bigfoot research. Presented by A&E Home Video.
Sasquatch Odyssey: The Hunt for Bigfoot
1999 60 minutes
This film presents a history of the search for Bigfoot, focusing primarily on four well-known
Sasquatch researchers: Peter Byrne, John Green, Rene Dahinden, and Grover Krantz. Presented
by Big Hairy Deal Films and Gryphon Productions Ltd., West Vancouver, BC, Canada.
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USING THE ATLAS
Using the Chapter 6 map, Evolution of Primates, discuss the distribution of early
primates. It is important to talk the order in which the taxa evolved as well as when and where
they first appeared. You can use this chapter to foreshadow the next two chapters in the textbook:
Early Hominids and Modern Humans. Discuss how the patterns observed during the Cenozoic
and Oligocene set the stage for later developments.
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