lecture_ch11[1].ppt - Chapter 11: Animal Diversification...

Chapter 11: Animal Diversification
Visibility in motion
Lectures by Mark Manteuffel, St. Louis Community College

Learning Goals

Define an animal and the key
distinctions that divide the species.

Discuss evolutionary success.

Define and describe
vertebrates and
their evolution.

Define and describe the terrestrial
vertebrates, including amphibians,
birds, and mammals.

Learning Goals

Describe early human lifestyles and
human evolution.

Define and describe the
invertebrates, including echinoderms,
arthropods, molluscs, annelids,
flatworms, cnidarians, and sponges.

Are some animals smarter than
others?

11.1 What is an animal?

Take-home message 11.1
Animals are organisms that share
three characteristics:

11.2 Four key
distinctions divide the
animals.

1) Does the animal have
defined tissues, with
specialized cells?

2) Does the animal develop
with radial symmetry or
bilateral symmetry?

3) During development, does the
animal’s gut develop from
front to back or back to front?
Protostomes
and
Deuterostomes

4) Does growth occur by molting
or by adding continuously to
the skeletal elements?

Take-home message 11.2

The animals probably originated from
an ancestral protist.

Four key distinctions divide the
extant animals:
1) tissue or not
2) radial or bilateral symmetry
3) protostome or deuterostome
development
4) growth through molting or not

11.3 Everything that is
not extinct is
evolutionarily successful.

What is “success”
evolutionarily?

Take-home message 11.3

From an evolutionary perspective,
all extant species are successful.

However, some groups are
represented by more species than
others.

Among the 36 animal phyla, 9 phyla
account for more than 96 percent of
all described animal species.

11.4 All vertebrates are
members of the phylum
Chordata.

Four
distinct
features of
chordates

The Notochord

A rod of tissue extending from the head
to the tail

Stiffens the body when muscles contract
during locomotion

In advanced chordates
•
present only in early embryos
•
replaced by the vertebral column (backbone)