1. 1.2-Determining How Species are Related
SBI3U1

2. 1.2 Determining How Species Are Related
UNIT 1
Chapter 1: Classifying Life’s Diversity
Section 1.2
1.2 Determining How Species Are Related
Hypotheses about the evolutionary history and relationships among different species are made based on three types of evidence:
Anatomy
Physiology
DNA

3. ANATOMY= the study of the structure of organisms
Example:
Biologists hypothesize a close evolutionary relationship btw. modern birds & dinosaurs based on similar bone structure in both organisms

4. PHYSIOLOGY= the study of the physical and chemical functions of organisms including internal processes
Example:
Genetic research was used to determine that guinea pigs are different from other rodents and should be placed in a different category. Their insulin proved to be very different from eachother.

5. DNA analysis among species is used to further understand evolutionary history
Example:
DNA evidence suggests that fungi are more similar to animals than plants

6. Therefore, we can conclude….
UNIT 1
Chapter 1: Classifying Life’s Diversity
Section 1.2
Therefore, we can conclude….
Species that have many anatomical, physiological, and molecular (DNA) characteristics in common are thought to share a common evolutionary ancestor.

7. UNIT 1
Chapter 1: Classifying Life’s Diversity
Section 1.2
Phylogenetic Trees
A phylogenetic tree is a branching diagram used to show the evolutionary relationships among species. (a.k.a. evolutionary tree)
CHECK YOUR UNDERSTANDING…
To which other organism is Cervus elaphus most closely related? At what rank and taxon are they related?
The animals shown here are all part of the order Artiodactyla.

8. http://highered. mcgraw-hill

9. The Importance of Classification
UNIT 1
Chapter 1: Classifying Life’s Diversity
Section 1.2
The Importance of Classification
Classification can assist in:
the discovery of new drugs, hormones, and other medical products
tracing the transmission of disease and the development and testing of possible treatments
increasing crop yields and disease and pest resistance
environmental conservation of organisms

10. HOMEWORK Read and make notes 1.2 pgs 17-22
Complete the following: Pg. 23 Q #1-4, 6