Tuesday, September 30, 2014

Natural Selection and Adaptation (Cont.)

Digest

  • Evolution by natural selection takes place when some individuals survive and reproduce better than others in a particular environment and the heritable characteristics of a population change from one generation to the other due to that.
  • Fitness is measured by the number of descendants left by individuals in a population.
  • Evolution is not perfect: Evolved individuals might have characteristics that are suited to the environments of their ancestors but not so much to their current environments.
  • Fitness is relative: evolved individuals can be the best fit for their current environments but not the perfect fit.
  • Precise matches between an organism and its environment may equally be seen as constraints making such organism dependent on such specific environment.

Questions

  1. Does fitness depend on the number of offspring only and why?
  2. What is the ultimate fitness?

Monday, September 29, 2014

Natural Selection and Adaptation

Digest

  • At the heart of ecology lies the relationship between organisms and their environments. Fundamentally, this is an evolutionary relationship.
  • Theodosius Dobzhansky, Russian-American biologist, said: "Nothing in biology makes sense, except in the light of evolution." This is also very true of ecology.
  • Adaptation: "Organism X is adapted to live in environment Y" means that environment Y has provided forces of natural selection that have affected the life of X’s ancestors and so have molded and specialized the evolution of X. Adaptation means that genetic change has occurred.
  • The theory of evolution by natural selection is an ecological theory.
  • It was first elaborated by Charles Darwin in 1859.
  • Its essence was also appreciated by his contemporary Alfred Russell Wallace.
  • The theory of evolution by natural selection rests on a series of propositions:
    • Individuals making up a population of a species are not identical
    • Some variation among individuals is heritable
    • Populations have the potential to populate the whole earth but they do not
    • Different ancestors have different numbers of descendants
    • Number of descendants an individual leaves depends crucially on the interaction between the characteristics of the individual and its environment

Questions

  1. Is evolution a theory in biology or ecology?
  2. What is the relationship between organisms and their environment?

Sunday, September 28, 2014

Organisms: Introduction

Digest

Approach

  • Constructive approach: Building up from organisms to populations to communities.
  • Analytically approach: Deconstructing from communities into populations and furthermore into organisms.
  • This book follows a constrictive rather than analytically approach in this regard.
Constructive approach
Constructive approach

Chatpers

  1. Chapter 1: Constraints of evolutionary history of organisms
  2. Chapter 2: Variation of environmental conditions with respect to place and time and their effect (limit) on the distribution of particular species.
  3. Chapter 3: Resources consumed by different types of organisms.
  4. Chapter 4: Variety in the schedules of birth and death (life histories)
  5. Chapter 5: Intraspecific competition for shared resources in short supply (interaction within single species populations)
  6. Chapter 6: Immigration and emigration
  7. Chapter 7: Applications: restoration, biosecurity, species conservation

Questions

  1. What role does the abundance of a specific species play in shaping a community?
  2. What will the chapters in Part I (Organisms) be covering?

Saturday, September 27, 2014

Introduction: Functions of Ecology

Digest

  • At all levels of ecological organization we can:
    • describe
    • explain
    • predict
    • control
  • Proximal vs. ultimate explanations
    • ultimate explanations are evolutionary based
  • Examples of uses of ecology:
    • minimize the effects of locust plagues
    • protecting crops by predicting when conditions will be favorable
    • maintain endangered species
    • conserve biodiversity to maintain ecosystem services
  • pure vs. applied ecology
    • applied ecology is based on the strong foundation of pure ecology
    • applied ecology has become important now partly due to political influence
Functions of ecology
Functions of ecology

Questions

  1. What are the uses of ecology?
  2. How has applied ecology developed and why has it become more important now?

Friday, September 26, 2014

Introduction: Definition and Scope of Ecology

Answers

  1. Ecology is the scientific study of the distribution and abundance of organisms and the interactions that determine distribution and abundance.
  2. This section does not cover the uses of ecology. Ecology covers organisms, populations, communities and ecosystems.

Digest

  • definition of ecology
  • history of how ecology was defined:
    • 1869 by Ernest Haeckel: Ecology is the scientific study of interactions between organisms and their environment. Haeckel is the one who coined the term ecology.
    • 1972 by Krebs: "Ecology is the scientific study of the interactions that determine the distribution and abundance of organisms."
    • Preferred definition: "Ecology is the scientific study of the distribution and abundance of organisms and the interactions that determine distribution and abundance."
    • 1992 by Likens: "Ecology is the scientific study of the distribution and abundance of organisms and the interactions between organisms and the transformation and flux of energy and matter."
  • Two approaches to taken by ecologists at each level of ecological organisation:
    • Building from properties at the level below: ex: physiology when studying organismal ecology
    • Directly with properties of the level of interest: ex: rate of biomass production at the ecosystem level
  • Biological hierarchy
  • Ecological organization:
  • biotic vs. abiotic
Ecological Organization
Ecological Organization

Questions

  1. What is the definition of ecology?
  2. What are the uses of ecology and what does it cover?

Thursday, September 25, 2014

Acknowledgements

Answers

  1. The two authors thank John Harper and other reviewers and helpers.
  2. The third author, John Harper, has left after finding that the pleasures of retirement and grandfatherhood overweighed those of co-authorship.
  3. Besides the two authors, John Harper and the reviewers of the first drafts of the first edition as well as those involved during the production stage in addition to many other names are all responsible for the success of this book.

Digest

  • Third author left out: John Harper
  • The two authors that remain are: Mike Begon and Colin Townsend
  • Both authors acknowledge their families
  • They acknowledge people during the production stage
  • There has been anonymous reviewers for the fourth edition
  • Comments of readers of first drafts of the first edition still appear in this fourth edition
  • The two authors pay tribute to the third author John Harper who is now out (retirement, grandfatherhood)
  • They have learnt from him
  • They have different views from his about some of the topics covered
  • His style (John Harper) they try to follow in this book which is:
    • respecting readers rather than patronizing them
    • inspiring rather than informing
    • respecting past while not following the current reputable people blindly
    • questioning rather than accepting blidndly

Questions

  1. Who do the authors thank?
  2. Why has the third author left?
  3. Who else is responsible for the success of this book?

Wednesday, September 24, 2014

Preface - Part 2

Digest

Book Features

  • website to accompany book: www.blackwellpublishing.com/begon contains:
    • artwork
    • glossary
    • interactive mathematical models
    • links to ecology websites
  • Authors published Essentials of Ecology to be a shorter textbook for those who will not study ecology again
  • 4th edition has been reduced 15% in size
  • John Harper, one of the 3 authors, is no longer participating in the 4th edition, he retired
  • each chapter contains summary
  • Textbook contains marginal notes as signposts that go along with the flow of the textbook and can also be read on their own. They can be used as a check for comprehension of the main section.
  • First edition was very large in an attempt to "overcome the opposition of all competing textbooks."
  • Ecology is a meeting-ground for: naturalists, experimentalists, field biologists and mathematical modelers. All ecologists should combine all these facets.
  • Results from around 800 studies have been newly incorporated into the 4th edition of this texbook. most of which were published since the third edition.
  • Different chapters of this book contain different proportions of:
    • descriptive natural history
    • physiology
    • behavior
    • laboratory and field experimentation
    • field monitoring and censusing
    • mathematical modeling

Questions

  1. What are the features of this book?
  2. What is unique about this book and differentiates it from others?
  3. What is the specific take and direction of this book?
  4. To whom is this book directed?
  5. Does this book use knowledge from ecology to position itself?

Tuesday, September 23, 2014

Preface - Part 1

Answers

  1. Yes 19 years indicates the time that has passed between the first and fourth edition of the textbook.
  2. This section is talking about "applied ecology" and not ecology as a whole. Applied ecology has come of age as of date of publication of the 4th edition of the textbook (2006).
  3. Ecology is hard because it deals with an enormous variation in genetics and number of species.
  4. Ecology is for everyone because every one of us has 'studied' the ecology around him even if on a very basic or superficial level.

Digest

  1. A science  for everybody - but not an easy science
    1. everyone has been an ecologist, oldest science
    2. evolution only makes sense in light of ecology
    3. Whitehead's recipe for science: "Seek simplicity, but distrust it."
    4. diversity of genetics, species
    5. Patterns
    6. Ecology is ... population, 3 levels: organisms, interactions among organisms, communities
  2. Nineteen years on: applied ecology has come of age
    1. the move towards applications (reflected in 3 chapters, one in each part of the book)
    2. some things have changed, some have remained fixed
    3. the cover has changed to reflect such changes
    4. man as perpetrator

Questions

  1. Does 19 years indicate start of first edition?
  2. Was ecology not "of age" 19 years ago or does the heading mean the textbook itself has matured?
  3. Why is ecology hard?
  4. Why does the author consider ecology to be a difficult science?

Monday, September 22, 2014

Ecology: from Individuals to Ecosystems - Book Overview

The following information is about the book Ecology: from Individuals to Ecosystems
  • The book is divided into 3 parts: Organisms; Species Interactions and Communities and Ecosystems
  • The book contains 22 chapters
  • Each of the 3 parts of the book concludes with a chapter about Ecological Applications
  • The book is 754 pages
Ecology textbook parts
Ecology textbook parts