The Animal Kingdom

Introduction to the Animal Kingdom D ©Holt ©1994, Lavia ©2003Tan & Yeo

A- Development from a blastula B- Determinant development with well-developed tissue layers C- Radial symmetry D- Bilateral Symmetry E- Blastopore becomes mouth F- Blastopore becomes anus Synapomorphies that define the major clades of the Animal Kingdom D

synapomorphy What is a synapomorphy ? Organisms share derived (apomorphic) character states… Provides evidence of evolutionary relationships between taxa D

TRACE CHARACTER… A- Development from a blastula Synapomorphies that define the major clades of the Animal Kingdom D

TRACE CHARACTER… B- Determinant development with well-developed tissue layers Synapomorphies that define the major clades of the Animal Kingdom D

TRACE CHARACTER… C- Radial symmetry D- Bilateral Symmetry Synapomorphies that define the major clades of the Animal Kingdom D

General Animal Life Cycle

Grades of Animal Groups Cell Grade Choanozoa Tissue Grade Parazoa Organ Grade Radiata Bilateria

THE ANIMAL KINGDOM 1. The Animal Clade 2. The Unicellular Animals 3. The Multicellular Animals 4. The Tissue-Level Grade 5. The Organ-Level Grade 6. The Radiate Animals 7. The Bilaterians 8. The Nephrozoans 9. The Deuterostomes 10. The Protostomes 11. The Ecdysozoans 12. The Spiralians

CHOANOFLAGELLATES Single-celled, colonial, eukaryotes Choanozoa

Parazoa

Radiata

The Bilateria Protostomata –Most animals Deuterostomata –Only a few taxa, including the Craniates and Echinoderms

Examples of Protostomes Nematoda

Examples of Protostomes Arthropoda

Examples of Protostomes Mollusca

Examples of Protostomes Platyhelminthes

Examples of Protostomes Syndermata

Examples of Deuterostomes Echinodermata

Major Events in the Evolution of the Animals Lemons and McGinnis Genomic Evolution of Hox Gene Clusters. Science. 313 (5795):

Major Events in the Evolution of the Animals Origin of animals following the period of Snowball Earth The Ediacaran Fauna

Major Events in the Evolution of the Animals Cambrian Explosion Rise in oxygen and ozone Rise in calcium Appearance of Hox genes Eyes Predator-prey arms race Increase in size