27.1 Evidence of Evolution

• Many fields of biology provide evidence that common descent has occurred.

1. List the categories of evidence in support of evolution.
   Answer
   
   
2. How long have unicellular prokaryotes existed compared to multicellular eukaryotes?
   Answer
   
   

Essential Study Partner
    Evidence for Evolution
    Geologic Time
    Fossils
    Continental Drift
    Extinctions
    Geologic Processes

Art Quizzes
    Embryos and Evolutionary History
    Cytochrome c Evolution
    Phylogenetic Tree of Globin Gene

Animation Quizzes
    Plate Tectonics
    Molecular Clock

General Biology Weblinks
    Evolutionary Biology

27.2 Origin of Life

• A chemical evolution proceeded from small organic molecules to macromolecules to protocell(s).
• The first cell was bounded by a membrane and contained a replicating system, that is, DNA, RNA, and proteins.

1. How was the primitive atmosphere that allowed for the evolution of simple organic molecules different from the atmosphere of earth today?
   Answer
   
   
2. Considering the origin of cells, which likely arose first – autotroph or heterotroph?
   Answer
   
   

Essential Study Partner
    Origin of Life
    Key Events

Art Quizzes
    Miller-Urey Experiment
    Miller-Urey Experiment Results
    Current Bubble Hypothesis

27.3 Process of Evolution

• Populations evolve and not individuals; evolution is defined in terms of population genetic changes.
• There are several agents of evolutionary change, one of which is natural selection.
• Natural selection is the mechanism resulting in adaptation to the environment.

1. List the five agents of evolutionary change.
   Answer
   
   
2. How do pesticides and antibiotics lead to resistant insects and bacteria, respectively?
   Answer
   
   

Essential Study Partner
    Natural Selection
    Types of Selection
    Variation
    Adaptation
    Other Processes
    Before Darwin
    Voyage of the Beagle

Art Quizzes
    Hardy-Weinberg Equilibrium
    Types of Natural Selection
    Evolutionary Pace
    Correlation Between Sickle Cell Allele and Malaria

Animation Quiz
    Hardy-Weinberg Equilibrium

27.4 Speciation

• New species come about when populations are reproductively isolated from other similar populations.

1. How do subpopulations become separate species?
   Answer
   
   
2. What are the two hypotheses about the pace of evolution and how do they differ?
   Answer
   
   

Essential Study Partner
    Introduction
    Allopatric Speciation
    Sympatric Speciation

27.5 Classification

• Species are classified into seven hierarchical categories according to shared characteristics. At each level above species, there are more and more types of species in the category.

1. What is phylogeny?
   Answer
   
   
2. What types of evidence supports the use of a three-domain system of classification?
   Answer
   
   
3. What is a common theme agreed on both traditionalists and cladists?
   Answer
   
   

Essential Study Partner
    Hierarchies
    Kingdoms
    Three Domains
    Constructing Phylogenies

Art Quizzes
    Taxonomic Hierarchy
    Traditional Versus Cladistic Taxonomy
    Tree of Life
    Evolutionary Relationships Among Kingdoms

General Biology Weblinks
    Taxonomy & Phylogenetics