Module 9S1 Ecological Interactions

Module 9S1 - Ecological Interactions

Introduction

In Module 9: Section 1, you will analyze complex ecosystems to identify the relationships between community members. You will see that each organism belongs to a given trophic level and has a role to play within the community. You will consider both interspecific and intraspecific competition for scarce resources. You will learn that individual organisms with alleles that allow the organism to compete better than others live to reproduce, thereby improving the population gene pool within that environment.
 
You will learn about predator/prey or producer/consumer interactions in a community’s food chain. You will learn how predators act as selecting agents, removing those with less successful alleles and leaving those whom are more genetically fit. You will come to understand that predators and prey cycle together through time as the populations of one control the numbers of the other. You will also see that prey species and producers have evolved many chemical, structural, and behavioral defences that protect them from consumption.
 
You will look at how an organism filling its niche in the food chain may have positive or negative effects on those it lives with. You will study mutualistic, commensal, and parasitic relationships among organisms.

 

You will study the changes that occur in communities as a geographical area ages. You will learn about succession and see how pioneer species invade a barren habitat and change the environment to the extent that the pioneer species can no longer survive there. Having prepared the environment, the pioneer species will be replaced by a more suitable species. As producer species change through succession, the consumer species who rely on them change as well. Does the changing cast of characters in successions indicate a problem?

 

In This Module

Section 1: Lesson 1—Species Interactions and Symbiotic Relationships

In this lesson you will learn to identify various interactions between species and explain the types of symbiotic relationships that exist between species.

The focusing questions being addressed in this lesson are:

• What are the relationships that exist between species and ecosystems?
• What is the effect these interactions have on population changes?

Section 1: Lesson 2—Role of Defense

In this lesson you will examine how organisms compete in every day relationships and how they protect themselves from members of other species.

The focusing question being addressed in this lesson is:

• What are the defence mechanisms within predation and competition?

Section 1: Lesson 3—Populations and Communities Changing Over Time—Succession

In this lesson you will explore the features and types of succession that are at work and constantly changing the environment.

The focusing question being addressed in this lesson is:

• How do communities and their populations change or remain stable over time?