Interest Grabber

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Interest Grabber
Section 32-1

• A Warm Body
• Because mammals and birds generate heat within
  their bodies, they are endotherms. Other types of
  chordates control body temperature by behavior.
  These animals are ectotherms.

1. Mammals and birds eat much more food than do
other types of chordates. Why do you think this
is necessary? 2. What body features do endotherms
have that would provide insulation to conserve
heat produced within the body? Would you expect
ectotherms to have such features? 3. What are two
examples of endotherms? What is the specific type
of insulation that each one has?
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Section Outline
Section 32-1

• 321 Introduction to the Mammals
• A. Evolution of Mammals
• B. Form and Function in Mammals
• 1. Body Temperature Control
• 2. Feeding
• 3. Respiration
• 4. Circulation
• 5. Excretion
• 6. Response
• 7. Chemical Controls
• 8. Fighting Disease
• 9. Movement
• 10. Reproduction
• 11. Interrelationships of Organ Systems

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The Structure of a Bears Heart
Section 32-1
Left atrium
Right atrium
Left ventricle
Right ventricle
Complete division
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Figure 324 The Jaws and Teeth of Mammals
Section 32-1
CARNIVORE
HERBIVORE
Jawjoint
Jaw joint
Horse
Wolf
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Interest Grabber
Section 32-2

• Marsupials Versus Placentals
• Kangaroos and humans are both mammals because of
  the characteristics they share. Still, they
  display enough different characteristics to
  result in a kangaroo being classified as a
  marsupial and a human being classified as a
  placental mammal. Consider what you know about
  kangaroos and humans, and then answer the
  questions that follow.

1. How do the young of kangaroos develop, and how
do the adults care for their young? 2. How do
humans and kangaroos differ from one another in
caring for their young? 3. What characteristic do
humans and kangaroos have in common in terms of
caring for their young?
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Section Outline
Section 32-2

• 322 Diversity of Mammals
• A. Monotremes and Marsupials
• 1. Monotremes
• 2. Marsupials
• B. Placental Mammals
• C. Biogeography of Mammals

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Compare/Contrast Table
Section 32-2
Orders of Placental Mammals
Order Insectivores Sirenians Cetaceans Chiropter
ans Rodents

Characteristics
Examples
Long, narrow snouts, sharp claws Water-dwelling,
slow-moving Live and breed in ocean, come to
surface to breathe Winged, capable of true
flight Single pair of long, curved incisor teeth
in upper and lower jaws
Shrews, hedgehogs, moles Manatees,
dugongs Whales, dolphins Bats Mice, rats, voles,
squirrels, beavers, porcupines, chinchillas
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Compare/Contrast Table continued
Section 32-2
Orders of Placental Mammals
Order Perissodactyls Carnivores Artiodactyls Pr
oboscideans
Characteristics
Examples
Hoofed, with an odd number of toes on each
foot Sharp teeth and claws Hoofed, with an even
number of toes on each foot Trunks
Horses, tapirs, rhinoceroses, zebras Tigers,
hyenas, dogs, foxes, bears, raccoons, walruses
Cattle, sheep, goats, pigs, ibex, giraffes,
hippopotami, camels Asian and African elephants,
mastodons and mammoths
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Compare/Contrast Table continued
Section 32-2
Orders of Placental Mammals
Order Lagomorphs Xenarthrans Primates
Characteristics
Examples
Two pairs of incisors in upper jaw, hind legs
allow leaping No teeth (or very small teeth in
the back of the jaw) Highly developed cerebrum
and complex behaviors
Snowshoe hares, rabbits Sloths, anteaters,
armadillos Lemurs, tarsiers, apes, gibbons,
macaques, humans
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Figure 3213 Convergent Evolution of
Insect-Eating Mammals
Section 32-2
ChinesePangolin
Nine-BandedArmadillo
CommonEchidna
Giant Anteater
Aardvark
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Interest Grabber
Section 32-3

• Skeletal Features of Primates
• Recall that primates are an order of mammals. One
  difference that exists between primates and other
  mammals is in the structure of the primate
  skeleton. Some examples of primates include
  humans, lemurs, monkeys, and apes.

1. How are the external features of your hands
different from the external features of the paws
of a dog or the hooves of a horse? 2. Primates
are bipedal, or capable of walking on two limbs.
What is an advantage of being bipedal? 3. What
are some characteristics of your skeleton that
enable you to stand and walk?
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Section Outline
Section 32-3

• 323 Primates and Human Origins
• A. What Is a Primate?
• 1. Fingers, Toes, and Shoulders
• 2. Well-Developed Cerebrum
• 3. Binocular Vision
• B. Evolution of Primates
• 1. Prosimians
• 2. Anthropoids
• C. Hominid Evolution
• 1. Early Hominids
• 2. Australopithecus
• 3. Paranthropus
• 4. Recent Hominid Discoveries
• 5. Rethinking Early Hominid Evolution

D. The Road to Modern Humans 1. The Genus
Homo 2. Out of AfricaBut Who and When? E. Modern
Homo sapiens
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Comparison of Skulls of Human Ancestors
Section 32-3
Large brow ridge
Large nose
Large canine teeth
Face protrudes forward
Australopithecus afarensis
Homo erectus
Round, high skull
Weak brow ridge
Large brain case
Inflated cheeks
Largenose
Even teeth
Strong chin
Neanderthal
Cro-Magnon
Modern Homo sapiens
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Figure 3216 Human and Gorilla Skeletons
Section 32-3
Comparing Human and Gorilla Skeletons
Modern Human
Modern Human
Modern Gorilla
Modern Gorilla
Skull atopS-shaped spine Spinal cord exitsat
bottom of skull Arms shorter thanlegs hands do
not touch groundduring walking Pelvis is
bowl-shaped Thigh bones angledinward,
directlybelow body
Skull atopC-shaped spine Spinal cord exitsnear
back of skull Arms longer thanlegs hands touch
ground during walking Pelvis is longand
narrow Thigh bones angledaway from pelvis
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Video Contents
Videos

• Click a hyperlink to choose a video.
• Primate Evolution
• Lucys Footprints

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Video 1
Video 1
Primate Evolution

• Click the image to play the video segment.

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Video 2
Video 2
Lucys Footprints
Click the image to play the video segment.
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Internet
Go Online

• Interactive test
• For links on mammals, go to www.SciLinks.org and
  enter the Web Code as follows cbn-9321.
• For links on human evolution, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-9322.

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Section 1 Answers
Interest Grabber Answers
1. Mammals and birds eat much more food than do
other types of chordates. Why do you think this
is necessary? Mammals and birds have higher
metabolic rates, which cause enormous food
requirements. The food is burned and heat is
generated as a result. 2. What body features do
endotherms have that would provide insulation to
conserve heat produced within the body? Would you
expect ectotherms to have such features? A layer
of body fat and hair, fur, or feathers. The other
groups of chordates have poor insulation. 3. What
are two examples of endotherms? What is the
specific type of insulation that each one
has? Examples A robin has body fat and
feathers, and a bear has body fat and fur.
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Section 2 Answers
Interest Grabber Answers
1. How do the young of kangaroos develop, and how
do the adults care for their young? Kangaroos
bear live, undeveloped young that complete their
development in an external pouch, where they
attach to a nipple for nourishment. 2. How do
humans and kangaroos differ from one another in
caring for their young? Human babies require
care (feeding, protecting, providing a place to
live) for a longer time. Human parents teach
their offspring more than any other animals
do. 3. What characteristic do humans and
kangaroos have in common in terms of caring for
their young? Newborns feed on the mothers milk
that is produced by mammary glands.
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Section 3 Answers
Interest Grabber Answers
1. How are the external features of your hands
different from the external features of the paws
of a dog or the hooves of a horse? The human
hand has fingers and is capable of manipulating
objects, which might allow the use of
tools. 2. Primates are bipedal, or capable of
walking on two limbs. What is an advantage of
being bipedal? Arms would be available for many
uses might allow a better view of the
environment. 3. What are some characteristics of
your skeleton that enable you to stand and
walk? Answers may include the curves of the
spine, the width of the pelvis, and the length of
the leg bones.
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End of Custom Shows

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