1. 7.5 Branching Trees

2. Branching Tree diagram : It shows probable evolutionary relationships among organisms.

3. Shared Derived Characteristics
A branching tree diagram shows evolutionary relationships by grouping organisms according to shared derived characteristics.
SDC : usually a homologous structure, such as a backbone, that is shared by all organisms in a group

4. Evolutionary groups A branching tree has groups within groups EX.
Animals with backbone: fishes, amphibians, and reptiles….
Animals with 4 limbs: amphibians and repltiles…..
Animals that produce eggs with shells : reptiles

5. Order of characteristics
Characteristics that appear lower on a branching tree probably developed before characteristics higher on the tree.
Backbones earlier than backbone & 4 limbs.

6. Constructing a Branching Tree
Do mosses have any of the characteristics indicated at the top of the table?
Which plant has the greatest number of characteristics?
Use this info to draw a branching tree.
Characteristics of Plants
Plant
True Roots
Seeds
Flowers
Moss No
Fern
Yes
Spruce Tree
Apple Tree

7. Review
How does a branching tree diagram divide organisms into groups?

8. Branching Trees RNTG 1. Shared Derived Characteristics
Branching tree diagram shows evolutionary relationships
A shared derived characteristic is usually a homologous structure
A branching tree has groups within groups
Characteristics on lower branches probably appeared first
2. II Constructing a Branching Tree
The base of the tree shows a common ancestor
Continue until a group has the greatest number of shared derived characteristics
Branching tree can show fossils as well as living organisms.

9. II Constructing a Branching Tree
The base of the tree shows a common ancestor
Continue until a group has the greatest number of shared derived characteristics
Branching tree can show fossils as well as living organisms.