by Miller & Levine
[complete Table of Contents]
the pull-down menu to jump to any of the Book's 40 Chapters:
chapter, students will read about the adaptations and evolution of mammals
and the major living groups of mammals. They will also read in more detail
about the evolution and characteristics of the primates, with an emphasis
on the evolution of humans. The links below lead to additional resources
to help you with this chapter. These include Hot Links to Web sites related
to the topics in this chapter, the Take It to the Net activities referred
to in your textbook, a Self-Test you can use to test your knowledge of
this chapter, and Teaching Links that instructors may find useful for
Section 32-1: Introduction
to the Mammals
In addition to
having hair and the ability to nourish their young with milk, all mammals
breathe air and are endotherms that generate their body heat internally.
The first true
mammals appeared during the late Triassic Period, about 220 million years
The ability of
mammals to regulate their body heat from within is an example of homeostasis.
As mammals evolved
to eat foods other than insects, the form and function of their jaws and
teeth became adapted to their diets.
The kidneys of
mammals help maintain homeostasis by excreting or retaining excess liquid.
Section 32-2: Diversity
The three groups
of living mammals are the monotremes, the marsupials, and the placentals.
Marsupials bear live young that complete their development in a pouch.
Monotremes lay eggs. In placental mammals, nutrients, oxygen, carbon dioxide,
and wastes are exchanged between embryo and mother through the placenta.
opportunities on the different continents have produced some striking
examples of convergent evolution in mammals.
Section 32-3: Primates
and Human Origins
In general, primates
have binocular vision, a well-developed cerebrum, fingers and toes, and
arms that rotate in their joints.
evolved from two of the earliest ancestral branches look very little like
typical monkeys and are called prosimians. Members of the more familiar
primate group that includes monkeys, apes, and humans are called anthropoids.
Today, most paleontologists
agree that the hominid fossil record includes at least five generaArdipithecus,
Australopithecus, Paranthropus, Kenyanthropus, and Homoand as many
as 16 separate hominid species. This diverse group of fossils covers roughly
4.5 million years.