1. CHAPTER 1 Introduction: The Scientific Study of Life
Modules 1.4 – 1.6

2. 1.4 The diversity of life can be arranged into three domains
EVOLUTION, UNITY, AND DIVERSITY
1.4 The diversity of life can be arranged into three domains
Grouping organisms by fundamental features helps make the vast diversity of life manageable for study
Scientists classify organisms into a hierarchy of broader and broader groups

3. Most classification schemes group organisms into three domains:
Domain Bacteria
Domain Archaea
Figure 1.4A, B

4. Domain Eukarya
Figure 1.4C-F

5. 1.5 Unity in diversity: All forms of life have common features
All organisms share a set of common features, signs of unity in life’s vast diversity
All are made of cells
All have DNA as their genetic blueprint
These orchids show the variety possible within one species
Figure 1.5A

6. DNA is made of chemical units called nucleotides
Each species has its own nucleotide sequence
Figure 1.5B

7. The genetic information in DNA underlies all of the features that distinguish life from nonlife
Order and regulation
Growth and development
Use of energy from the environment
Response to environmental stimuli
Ability to reproduce
Evolutionary change

8. 1.6 Evolution explains the unity and diversity of life
Charles Darwin is a central figure in biology
He synthesized the theory of evolution by natural selection
A theory in science is a comprehensive idea with broad explanatory power
Evolution is the core theme of biology
Figure 1.6A

9. The theory of natural selection explains the main mechanism whereby all species of organisms change, or evolve
(1) Population with varied inherited traits
(2) Elimination of individuals with certain traits
Figure 1.6B
(3) Reproduction of survivors

10. Evolution happens when populations of organisms with inherited variations are exposed to environmental factors that favor the success of some individuals over others
Natural selection is the editing mechanism
Evolution is based on adaptations
Figure 1.6C