- describe the various forms of natural selection and other factors that can result in evolutionary change
- describe the process of speciation
- describe and explain major patterns of evolutionary change
- apply the theory of evolution and use it to make testable predictions
- outline major steps in human evolution
- explain how human actions influence the evolution of species and extinction rates
What Steps Lead to the Evolution of New Species?
Darwin's theory of evolution by natural selection and the evidence that supports it have convinced biologists that Earth's biodiversity—the millions of species alive today, as well as the countless millions that have lived in the past and are now extinct—are all products of evolutionary change.
Given our understanding of DNA, inheritance, and mutation, it is not difficult to accept that the genetic makeup of a species might change over time. In addition, given the human experience in plant and animal domestication, it is also quite obvious that selection can lead to significant changes in species over time. But how can selection and mutation result in major evolutionary changes, including the evolution of millions of different species? And why, if the theory of evolution is true, are there still so many "primitive" species? Why have all species not evolved into more advanced organisms? As you will learn, the answers hinge on the word “different?”
Each of the millions of different species that are living and have lived on Earth is unique. Each species has specialized features that make it well suited to a particular ecological niche in a particular place and time. The mudskipper in the photograph on the next page is a wonderful living example of a specialized species. Mudskippers are amphibious fish, spending part of their time under water and part on land. When tides are low, mudskippers move around on the exposed beach, capturing small prey and defending their territory. During high tide or when they are threatened, they hide in burrows that they dig in the soft substrate. Mudskippers have many adaptations that support this lifestyle. Like many frogs, they can breathe through their damp skin and the roofs of their mouths. When on land, they also trap large bubbles of air inside their gill pouches to provide more oxygen to the gills than would be available in a small pocket of water. It would be a mistake to think that these fish are "on their way" to becoming fully terrestrial vertebrates. Instead, we should recognize that they are filling an ecological niche that favours their success.
In this chapter you will learn how different factors and circumstances have led to both the evolution of species, including our own, and to mass extinction events. You will also learn how understanding the evolutionary history of a species can be of benefit today.
STARTING POINTS
Answer the following questions using your current knowledge. You will have a chance to revisit these questions later, applying concepts and skills from the chapter.
1. What human characteristics or adaptations do you think are most responsible for our success as a species?
2. What human features do you consider least advantageous? In what ways are some human features disadvantageous under certain conditions?
3. Brainstorm possible situations that you think might cause one species to evolve into two different species.
4. Extinction is a natural process. Do you think there is any reason to be worried about species becoming extinct today? Explain your reasoning.
5. Do you think it is possible for human actions to influence how other non-domesticated species evolve? If so, how?
Friday, Nov. 24th, 2017 * Tutorial 1 in 8.5 (Constructing Cladograms) Do 8.5 Questions #8 on p.355 (go to mynelson.com for text with cladogram)
Unit 3 Self-quiz and review due Monday, Nov. 27th, 2017 Do all of the self-quiz Review: *Do all MC,T/F, and Matching questions For choose 5 questions from from#34-137to answer (1 K/U, 2 T/I, 2 A). Write a short answer to each chosen question.
The Origin of Species
KEY CONCEPTS
After completing this chapter you will be able to
- describe the various forms of natural selection and other factors that can result in evolutionary change
- describe the process of speciation
- describe and explain major patterns of evolutionary change
- apply the theory of evolution and use it to make testable predictions
- outline major steps in human evolution
- explain how human actions influence the evolution of species and extinction rates
What Steps Lead to the Evolution of New Species?
Darwin's theory of evolution by natural selection and the evidence that supports it have convinced biologists that Earth's biodiversity—the millions of species alive today, as well as the countless millions that have lived in the past and are now extinct—are all products of evolutionary change.
Given our understanding of DNA, inheritance, and mutation, it is not difficult to accept that the genetic makeup of a species might change over time. In addition, given the human experience in plant and animal domestication, it is also quite obvious that selection can lead to significant changes in species over time. But how can selection and mutation result in major evolutionary changes, including the evolution of millions of different species? And why, if the theory of evolution is true, are there still so many "primitive" species? Why have all species not evolved into more advanced organisms? As you will learn, the answers hinge on the word “different?”
Each of the millions of different species that are living and have lived on Earth is unique. Each species has specialized features that make it well suited to a particular ecological niche in a particular place and time. The mudskipper in the photograph on the next page is a wonderful living example of a specialized species. Mudskippers are amphibious fish, spending part of their time under water and part on land. When tides are low, mudskippers move around on the exposed beach, capturing small prey and defending their territory. During high tide or when they are threatened, they hide in burrows that they dig in the soft substrate. Mudskippers have many adaptations that support this lifestyle. Like many frogs, they can breathe through their damp skin and the roofs of their mouths. When on land, they also trap large bubbles of air inside their gill pouches to provide more oxygen to the gills than would be available in a small pocket of water. It would be a mistake to think that these fish are "on their way" to becoming fully terrestrial vertebrates. Instead, we should recognize that they are filling an ecological niche that favours their success.
In this chapter you will learn how different factors and circumstances have led to both the evolution of species, including our own, and to mass extinction events. You will also learn how understanding the evolutionary history of a species can be of benefit today.
STARTING POINTS
Answer the following questions using your current knowledge. You will have a chance to revisit these questions later, applying concepts and skills from the chapter.
1. What human characteristics or adaptations do you think are most responsible for our success as a species?
2. What human features do you consider least advantageous? In what ways are some human features disadvantageous under certain conditions?
3. Brainstorm possible situations that you think might cause one species to evolve into two different species.
4. Extinction is a natural process. Do you think there is any reason to be worried about species becoming extinct today? Explain your reasoning.
5. Do you think it is possible for human actions to influence how other non-domesticated species evolve? If so, how?
8.1 Natural Selection
8.2 Speciation
8.3 Patterns of Evolution
8.5 Macroevolution
8.6 Biology JOURNAL: Tiktaalik -- Triumph of a Theory ASSIGNMENT due Thursday, Nov. 23rd, 2017
8.7 Human Evolution
Thursday, Nov. 23rd, 2017
Chapter 8 Self-quiz and Review
Friday, Nov. 24th, 2017
* Tutorial 1 in 8.5 (Constructing Cladograms)
Do 8.5 Questions #8 on p.355 (go to mynelson.com for text with cladogram)
Unit 3 Self-quiz and review due Monday, Nov. 27th, 2017
Do all of the self-quiz
Review:
*Do all MC,T/F, and Matching questions
For choose 5 questions from from #34-137 to answer (1 K/U, 2 T/I, 2 A). Write a short answer to each chosen question.
Unit Test Tuesday, Nov. 28th, 2017
Bonus assignment: Investigation 8.5.1