Book cover for Biology

Biology

Sylvia S. Mader, Michael Windelspecht

ISBN #9780078024269

12th Edition

687 Questions

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153,501 Students Helped

Homework Questions

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Summary
Learning Objectives
Key Concepts
Example Problems
Explanations
Common Mistakes

Summary

This chapter traces the progression of evolutionary thought from early fixed-species ideologies to Darwin’s revolutionary concept of natural selection. It emphasizes the role of Darwin’s voyage on the HMS Beagle in gathering diverse evidence—ranging from fossils to biochemical data—that supports the theory of evolution and the idea that all life shares a common ancestry. The interconnectedness and dynamic nature of life are key learnings from this chapter.

Learning Objectives

1

Describe the historical development of evolutionary thought from the idea of fixed species to Darwin’s theory of evolution by natural selection.

2

Explain the key components of Darwin's theory, including the role of natural selection and the significance of his voyage on the HMS Beagle.

3

Analyze the diverse evidence supporting evolution, such as fossils, anatomical similarities, biogeographical patterns, and biochemical data.

4

Understand the concept of common ancestry and how it unites all life on Earth.

Key Concepts

CONCEPT

DEFINITION

Evolution

The process by which species change over time through genetic variation and natural selection.

Natural Selection

The mechanism by which individuals with traits better suited to their environment reproduce more successfully, leading to evolutionary change.

Common Ancestry

The concept that all living organisms share a common origin and have evolved from a common ancestor.

Fossils

The preserved remains or traces of organisms from the past, providing evidence for the history of life on Earth.

Anatomical Similarities

Structural similarities among different species that indicate a shared evolutionary history.

Biogeographical Patterns

The geographic distribution of species that reflects historical and evolutionary processes.

Biochemical Data

Molecular evidence from DNA, proteins, and other biological molecules that supports the shared ancestry of life.

Example Problems

Example 1

Which of these pairs is mismatched? a. Charles Darwin—natural selection b. Linnaeus—classified organisms according to the scala naturae c. Cuvier—series of catastrophes explains the fossil record d. Lamarck—uniformitarianism e. Thomas Malthus—principles of population

Example 2

Which scientist’s information on geology helped support the observations Darwin made during his voyage aboard the HMS Beagle? a. Erasmus Darwin b. Georges Cuvier c. Aristotle d. Carolus Linnaeus e. Charles Lyell

Example 3

According to the theory of inheritance of acquired characteristics, a. if a man loses his hand, then his children will also be missing a hand. b. changes in phenotype are passed on by way of the genotype to the next generation. c. organisms are able to bring about a change in their phenotype. d. evolution is striving toward improving particular traits. e. All of these are correct.

Example 4

Why was it helpful to Darwin to learn that Lyell thought the Earth was very old? a. An old Earth has more fossils than a new Earth. b. It meant there was enough time for evolution to have occurred slowly. c. There was enough time for the same species to spread out into all continents. d. Darwin said that artificial selection occurs slowly. e. All of these are correct.

Example 5

The distribution of organisms across Earth is known as a. biogeography. b. uniformitarianism. c. paleontology. d. evolution. e. strata.
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Step-by-Step Explanations

QUESTION

How does Darwin’s theory of evolution explain the emergence of species over time?

STEP-BY-STEP ANSWER:

Step 1: Understand that Darwin’s theory proposes species are not fixed but change over time.
Step 2: Recognize that natural selection is the process where individuals with advantageous traits are more likely to survive and reproduce.
Step 3: Note that Darwin gathered evidence from fossils, anatomical structures, and geographic distribution of species during his voyage on the HMS Beagle.
Step 4: Connect the idea that these variations accumulate over generations, leading to the development of new species.
Final Answer: Darwin’s theory explains that through natural selection, advantageous traits become more common, leading to gradual changes and the evolution of species over time.

Darwin's Theory of Evolution

QUESTION

What types of evidence support the theory of evolution and how do they collectively demonstrate common ancestry?

STEP-BY-STEP ANSWER:

Step 1: Identify the fossil record that shows a succession of organisms from ancient to modern times.
Step 2: Examine anatomical similarities among different species which indicate inherited structures from common ancestors.
Step 3: Look at biogeographical patterns that reveal the historical distribution and migration of species.
Step 4: Consider biochemical data, such as genetic sequences, that confirm molecular similarities between related organisms.
Final Answer: Fossils, anatomical similarities, biogeographical patterns, and biochemical data together provide strong evidence that all life on Earth shares a common ancestry and has evolved over time.

Evidence for Evolution

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Common Mistakes

  • Assuming evolution is a linear progression rather than a branching tree of life.
  • Confusing the process of natural selection with the idea of purposeful adaptation or improvement.
  • Overlooking the accumulation of evidence from multiple scientific disciplines that collectively supports evolutionary theory.
  • Thinking that evolution occurs at the level of individuals rather than populations over time.