Chapter 1 - Introduction

Question 1

Define ecology.

Answer 1

The scientific study of the abundance and distribution of organisms in relation to other organisms and environmental conditions.

Question 2

Why is ecology referred to as “the economy of nature”.

Answer 2

Ecology can be seen as the transactions/business of survival and how this is conducted between organisms and their environments.

Question 3

List the ecological system hierarchy.

Answer 3

Individual, population, community, ecosystem, biosphere.

Question 4

What is an ecological system?

Answer 4

A biological entity that has its own internal processes and interacts with its external surroundings.

Question 5

What is an individual?

Answer 5

A living being, the most fundamental unit of ecology.

Question 6

Define a species.

Answer 6

Historically defined as a group of organisms that naturally interbreed with each other and produce fertile offspring. Current research demonstrates no single definition can be applied to all organisms.

Question 7

Why can’t reproductive isolation be used to draw the line between species?

Answer 7

Three examples:
Some species consist of only females that reproduce by producing clones of themselves.
Some species can interbreed and produce infertile offspring (the mule).
Horizontal gene transfer in bacteria.

Question 8

What are the five distinct properties of populations not exhibited by individuals?

Answer 8

Geographic range, abundance, density, change in size and composition.

Question 9

Define a population.

Answer 9

The individuals of the same species living in a particular area.

Question 10

Define a community.

Answer 10

All populations of species living together in a particular area.

Question 11

Are the boundaries that define a community or ecosystem always rigid?

Answer 11

No, ecologists often have to establish these boundaries for themselves when investigating a community/ecosystem of interest.

Question 12

Define an ecosystem.

Answer 12

One or more communities of living organisms interacting with their nonliving and chemical environments.

Question 13

What is usually focused on at the ecosystem level?

Answer 13

The movement of energy and matter between physical and biological components of the ecosystem.

Question 14

What is the biosphere?

Answer 14

The highest level of the ecological hierarchy. All of the ecosystems on Earth.

Question 15

Explain the individual approach to ecology.

Answer 15

An approach to ecology that emphasizes the way in which an individual’s morphology, physiology and behaviour enable it to survive in its environment. Adaptations are of key interest in this approach.

Question 16

Define an adaptation.

Answer 16

A characteristic of an organism that makes it well-suited to its environment.

Question 17

Explain the population approach.

Answer 17

An approach to ecology that emphasizes variation over time and space in the number of individuals, the density of individuals and the composition of individuals.

Question 18

Explain the ecosystem approach to ecology.

Answer 18

Emphasizes the storage and transfer of energy and matter, including the various chemical elements essential to life.

Question 19

Explain the biosphere approach to ecology.

Answer 19

Concerned with the largest scale in the hierarchy of ecological systems, including movements of air and water over Earth’s surface.

Question 20

Can the different approaches to ecology be combined.

Answer 20

Yes, and ecologists often use a combination of the approaches when gathering data.

Question 21

Explain the law of conservation of matter.

Answer 21

Matter cannot be created or destroyed; it can only change form.

Question 22

Explain the first law of thermodynamics.

Answer 22

Energy cannot be created or destroyed; it can only change form.

Question 23

Why are the law of conservation of matter and the first law of thermodynamics important to ecology?

Answer 23

They imply that matter and energy can be tracked by ecologists as they are converted to new forms throughout the ecological hierarchy.

Question 24

What is the dynamic steady state? Why is it important to ecology?

Answer 24

When the gains and losses of ecological systems are in balance. One of the biggest areas of interest for ecologists is to understand how ecological systems maintain and regulate their steady states.

Question 25

Identify the inputs and outputs that must be equal to maintain steady states at all levels of the ecological hierarchy.

Answer 25

Individual: food –> energy expended; waste
Population; Births & immigration –> Deaths & emigration
Community: Colonization by new species –> extinction of species
Ecosystem: solar energy and matter entering the ecosystem –> energy and matter leaving
Biosphere: solar energy entering –> energy re-radiated to space.

Question 26

What is a phenotype?

Answer 26

An attribute of an organism.

Question 27

What is a genotype?

Answer 27

The set of genes an organism carries.

Question 28

Define evolution.

Answer 28

Change in the genetic composition of a population over time.

Question 29

Define natural selection.

Answer 29

Change in the frequency of genes in a population through differential survival and reproduction of individuals that possess certain phenotypes.

Question 30

What 3 conditions does natural selection depend upon?

Answer 30

1. Individual organisms vary in their traits.
2. Parental traits are inherited by offspring.
3. Variation in traits causes some individuals to experience higher fitness.

Question 31

Define fitness.

Answer 31

The survival and reproduction of an individual.

Question 32

True or false: species evolve in isolation.

Answer 32

False

Question 33

What was the key event in the evolution of eukaryotes?

Answer 33

When a bacterium engulfed another, resulting in the mitochondrion.

Question 34

What are the three steps of the scientific method?

Answer 34

1. Make observations regarding a certain pattern in nature.
2. Development of a hypothesis.
3. Testing the hypothesis.

Question 35

What is a hypothesis?

Answer 35

An idea that potentially explains a repeated observation.

Question 36

Differentiate between proximate and ultimate hypotheses.

Answer 36

A proximate hypothesis addresses the immediate changes in an organism’s hormones, physiology, nervous system or muscular system.
An ultimate hypothesis address why an organism responds in a certain way to its environment in terms of the fitness and benefits of the response.

Question 37

What is a prediction?

Answer 37

A logical consequence of a hypothesis.

Question 38

What is a manipulative experiment?

Answer 38

A process by which a hypothesis is tested by altering a factor that is hypothesized to be an underlying cause of the phenomenon.

Question 39

What is a manipulation/treatment in an experiment?

Answer 39

The factor that we want to vary in an experiment.

Question 40

What is the control in an experiment?

Answer 40

A manipulation that includes all aspects of an experiment except the factor of interest.

Question 41

What is an experimental unit?

Answer 41

The objects to which we apply an experimental manipulation.

Question 42

What does it mean for an experiment to be replicable?

Answer 42

The experiment can produce a similar outcome multiple times.

Question 43

What is randomization?

Answer 43

An aspect of an experiment design in which every experimental unit has an equal chance of being assigned a particular manipulation.

Question 44

What is a microcosm?

Answer 44

A simplified ecological system that attempts to replicate the essential features of an ecological system in a laboratory or field setting.

Question 45

Why might it not be possible to test a hypothesis via an experiment?

Answer 45

Too much time/money required, would require too much space, variables cannot be isolated, an appropriate control cannot be used.

Question 46

What is a natural experiment?

Answer 46

An approach to hypothesis testing that relies on natural variation in the environment.

Question 47

What is a mathematical model?

Answer 47

A representation of a system with a set of equations that correspond to hypothesized relationships among the system’s components.