New Animal Classification System Define Animal Animalia is

New Animal Classification System!!

Define: Animal

Animalia is Monophyletic!

Major Divisions within Animalia Dueterostomes Protostomes

Informal Groups Let’s apply these to a phylogenetic tree

Key Events in Animal Evolution

Key Features of the Animal Body Plan

Why is Bilateral symmetry so prolific?

Generalized Animalia Embryo Development https: //www. youtu be. com/watch? v= d. Xp. Abezd. Oho

Cleavage and Gastrulation

Embryological Development Protostome

Embryological Development Deuterostome

Key Features of the Animal Body Plan • Evolution of Tissues – – – Cells organize into layers Two layers in primitive animals Three layers in “complex” animals What types of systems develop from these germ layers? Zebrafish embryo

Key Features of the Animal Body Plan • • Need complex organs and systems Evolution of body cavity Two major functions Organisms grouped into one of three categories

Body Cavity Structure

Key Features of the Animal Body Plan • Concentration of function at anterior end of body – i. e. head • Only in bilateral symmetry

Key Features of the Animal Body Plan • Evolution of Segmentation • Most animals possess segmented bodies during some stage • 3 benefits of segmentation

Other Key Features of the Animal Body Plan • No circulatory system • Open circulatory system • Closed circulatory system