The Theory of Evolution on Natural Selection - PowerPoint PPT Presentation


PPT – The Theory of Evolution on Natural Selection PowerPoint presentation | free to download - id: 6ddc8f-ZjUxN


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation

The Theory of Evolution on Natural Selection


The Theory of Evolution on Natural Selection Luis Mayo ... Section 1 Review Questions on Page 282 of the Holt Biology ... Cleaning up is part of your lab grade. 12. – PowerPoint PPT presentation

Number of Views:79
Avg rating:3.0/5.0
Date added: 21 February 2020
Slides: 67
Provided by: LuisA169
Learn more at:


Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: The Theory of Evolution on Natural Selection

The Theory of Evolution on Natural Selection
  • Luis Mayo
  • EDT 610
  • June 24, 2009

Bellringer Exercise
  • Explain the following statements in your own
  • Long Life Span
  • Short Life Span
  • Write a paragraph relating an organisms life
    span to the potential rate of evolution of a

Bellringer Exercise
  • Once all students have completed writing the
    paragraph, the class will discuss their answers.
  • Additionally, a discussion on the topic of
    evolution will take place.
  • Make sure that you respect your classmates when
    they are discussing the topic!

The Main Ideas
  • What is natural selection?
  • What are the observations that led Darwin to
    conclude that species evolve?
  • What are the main points of the Theory of
    Evolution on Natural Selection?
  • What is the effect of natural selection in a

Review of the Principles of Evolution
  • Evolution is a gradual change over a period of
  • It deals with the orderly changes that have
    shaped Earth.
  • Additionally, it has modified the living species
    that inhabit Earth.

Review of the Principles of Evolution
  • Evidence of evolution comes from each of the
  • A) the geologic record
  • B) fossil evidence
  • C) cell studies
  • D) genetics
  • E) comparative anatomy
  • F) comparative embryology

Review of the Principles of Evolution
  • The Geologic Record

Review of the Principles of Evolution
  • Fossils

Review of the Principles of Evolution
  • Cell Studies
  • Genetics

Review of the Principles of Evolution
  • Comparative Anatomy
  • Comparative Embryology

What is Natural Selection?
  • In your own words, write down what do you think
    is natural selection?
  • Construction paper and markers will be handed out
    so that you can create your definition.
  • Pictures may also be drawn to depict the
    terminology of natural selection.

What is Natural Selection?
  • Definition individuals that have physical or
    behavioral traits that better suit their
    environment are more likely to survive and will
    reproduce more successfully than those that do
    not have such traits
  • Natural selection can also be described as
    survival of the fittest!

Evolution by Natural Selection
  • Theories
  • Jean Baptiste Lamarck
  • 1. Proposed that differences
  • among animals and plants
  • were due to changes that
  • caused significant
  • variations among species.
  • 2. Lamarck believed that
  • changes are going on all
  • of the time because
  • evolution is a continuous
  • process.

Evolution by Natural Selection
  • 3. He believed that systems body structures
  • developed in response to use, and those
  • structures in disuse eventually
  • 4. He believed that acquired characteristics
    could be passed on from parent to offspring.

Evolution by Natural Selection
  • Charles Darwin
  • 1. British naturalist who became famous for his
    theories of evolution natural selection.
  • 2. He believed that all life on earth evolved
    (developed gradually) over millions of years from
    a few common ancestors.

Evolution by Natural Selection
  • 3. From 1831 1836, Darwin served as a
    naturalist aboard the H.M.S. Beagle on a
    British science expedition around the world.
  • 4. In South America, Darwin found fossils of
    extinct animals that were similar to modern

Evolution by Natural Selection
  • 5. On the Galapagos Islands in the Pacific Ocean,
    he noticed many variations among plants and
    animals of the same general types as those in
    South America.
  • 6. Upon his return to London, Darwin conducted
    thorough research of his notes specimens.

Darwins Voyage
An Example of Darwins Observations
Evolution by Natural Selection
  • Out of this study grew several related theories
  • Evolution did occur
  • 2. Evolutionary change was gradual, requiring
    thousands to millions of years
  • The primary mechanism for evolution was a process
    called natural selection
  • 4. Millions of species alive today arose from a
    single original life form through a branching
    process called specialization

Evolution by Natural Selection
  • Charles Darwins Theory of Evolution on Natural
    Selection holds that variation within species
    occurs randomly that the survival or extinction
    of each organism is determined by that organisms
    ability to adapt to its environment.

Evolution by Natural Selection
  • Darwin concluded the following
  • The best adapted individuals in a population
    survive produce offspring that are likewise
    well adapted
  • The least adapted individuals produce fewer
  • Suitable variations are passed on from one
    generation to the next
  • Other variations are lost

Evolution by Natural Selection
  • Variation marked difference or deviation from
    the normal or recognized form, function, or
  • Also, it refers to an organism or plant
    exhibiting such difference or deviation.

Evolution by Natural Selection
  • Three causes of variation
  • gene flow the movement of new
  • genes into a population
  • acts against the effects of natural selection

Evolution by Natural Selection
  • 2. genetic drift a change in a gene pool that
    takes place in a population as a result of chance
  • If a mutation occurs in a gene of one person,
    that person does not reproduce, the gene is lost
    to the population.

Evolution by Natural Selection
  • 3. speciation forming of one or more new
  • species from a species already in existence
  • Occurs when a population becomes divided part
    of the original species continues life in a new

Evolution by Natural Selection
  • Darwin further suggested that organisms are
    different from place to place because their
    habitats present different challenges to, and
    opportunities for, survival and reproduction.

Evolution by Natural Selection
  • Each species has evolved and accumulated
    adaptations in response to a particular
  • adaptation an inherited trait that has become
    common in a population because the trait provides
    a selective advantage

Evolution by Natural Selection
  • Another factor affecting natural selection is
    time frame.
  • It is believed that there is a time frame for
  • Gradualism supports the idea that evolutionary
    change is slow, gradual, continuous.

Evolution by Natural Selection
  • Punctuated equilibrium states that species have
    long periods of stability, lasting for 4 or 5
    millions years, suddenly change as a result of
    some geological or other environmental change.

Natural Selection Assignment
  • There will be ten questions pertaining to todays
    lesson .
  • These questions will be on a handout.
  • Answer each of the following questions pertaining
    to natural selection in complete sentences. The
    lecture notes and textbook may be used to help
    you answer each question.
  • Each response should be a short answer.
  • Once you have completed the assignment, hand it
    in to the teacher for a grade.

Natural Selection Assignment Sample
Galapagos Islands Activity
  • Using the Internet in the science computer lab,
    look up pictures of animal and plant species on
    the Galapagos Island.
  • You should have 5 different animal species, and 5
    different plant species.

Galapagos Islands Activity
  • Once you have found pictures of those species,
    make a comparison of those organisms to those
    found on the nearby continent of South America.
  • After analyzing and comparing those living
    beings, in small groups, you will be asked to
    write down the similarities and differences of
    those organisms.
  • Once all groups have completed this activity, a
    discussion will take place in the classroom on
    what are the possible explanations of those
    similar looking species for having different

The Galapagos Islands
  • Charles Darwin found evidence that challenged the
    traditional belief that species do not change
    over time.
  • Darwin visited the Galapagos Islands, which are
    located 620 miles off the coast of Ecuador.
  • Darwin was struck by the fact that many of the
    animal and plant species found on the Galapagos
    Islands resembled those found along the coast of
    South America.

Animals of the Galapagos Islands
Plants of the Galapagos Islands
Observations of the Galapagos IslandsAssignment
  • You will watch a documentary on the Galapagos
  • A worksheet will be given out where you must
    answer questions while watching the film.
  • All of the questions are in order of the video.
  • Once the video has finished, the teacher will go
    over the questions of the video worksheet.

Observations of the Galapagos IslandsAssignment
  • Video Worksheet Sample

Observations of the Galapagos IslandsAssignment
  • After watching the video, you will discuss
    independently on an essay why do you feel that
    species evolve over time?
  • You must give examples in the essay proving the
  • Also, the essay must be written using correct
    grammar and sentence structure.

Natural Selection and Galapagos Islands Review
  • The class will be divided into two teams and will
    be asked questions on the material taught thus
    far. There will also be questions from the
    Galapagos video.
  • The team with the most points will be given a
    Certificate of Excellence award that can be
    used as a credit on a missing assignment that a
    student may not have turned in to the teacher.

Question 1 What concept identified by Charles
Darwin can be describes as the survival of the
A. microscopy
B. natural selection
C. relativity
D. specialization
Question 2 What continent is located near the
Galapagos Islands?

A. Asia
B. Europe
C. North America
D. South America
Question 3 Which of the following animals
refers to name Galapagos?

A. albatross

B. giant tortoise

C. marine iguana

D. sea lion
Publication of Darwins Work
  • In 1844, Darwin finally wrote down his ideas
    about evolution and natural selection.
  • In 1858, he decided to publish his work after he
    received a letter and essay from Alfred Russel
    Wallace, an English naturalist.

Publication of Darwins Work
  • Alfred Wallace was in Malaysia and also described
    a concept of evolution via natural selection.
  • In the letter, he asked Darwin if he would help
    him get the essay published.
  • With help from friends, Darwin was able to
    present his concept of natural selection, along
    with Wallaces paper at a scientific meeting.

Darwins Theory
  • In 1859, Charles Darwins book, On the Origin of
    Species by Means of Natural Selection was
  • Many people were disturbed by his theory,
    especially when it discussed the evolution of
  • Despite such controversy, Darwins evidence and
    observations slowly convinced biologists around
    the world.

Darwins Theory
  • Four main points support Charles Darwins Theory
    of Evolution on Natural Selection
  • Inherited variation exists within the genes of
    every population or species (the result of random
    mutation and translation errors).
  • In a particular environment, some individuals of
    a population or species are better suited to
    survive (as a result of variation) and have more
    offspring (natural selection).

Darwins Theory
  • 3. Over time, the traits that make certain
    individuals of a population able to survive and
    reproduce tend to spread in that population.
  • 4. There is overwhelming evidence from fossils
    and many other sources that living species
    evolved from organisms that are extinct.

Darwins Theory
  • Darwins based his theory on the idea that in any
    population, individuals that are best suited to
    survive and do well in their environment will
    produce the most offspring.
  • Today, scientists know that genes are responsible
    for inherited traits.
  • Therefore, certain variations of a trait become
    more common in a population because more
    individuals in the population carry the genes.

Darwins Theory and Matching Assignment
  • In your own words, summarize the main points of
    the Theory of Evolution on Natural Selection in
    terms of how it is stated in modern times.
  • Matching Assignment Instructions
  • Each of the examples listed on the worksheet
    depicts a major point of natural selection.
    Match the example listed on the worksheet with
    one of the four main points of natural selection.

Darwins Theory and Matching Assignment
  • There will be ten examples that must be matched
    up to one of the four points of natural
  • You can only choose one of the four main points
    per example listed on the handout.

Simulating Natural Selection
  • You will receive a laboratory assignment on
    simulating natural selection using teddy graham
  • You are to read the Introduction and answer the
    question listed on the next page. Make sure to
    answer each question in complete sentences. All
    answers are to be written on the Data Sheet on
    page 5.

Simulating Natural Selection
  • Pre-lab Questions
  • Who wrote the Theory of Natural Selection?
  • If all organisms were identical, would natural
    selection happen? Explain.
  • If organisms did not to compete for basic needs,
    how would natural selection be affected?
  • What is another way of describing natural
  • How is artificial selection different from
    natural selection?
  • What might happen to a species if we move an
    exotic species into an area, which competes with
    it for basic needs and resources?

Simulating Natural Selection
  • Procedures
  • 1. Read the story below
  • You are a bear-eating monster. There are two
    kinds of bears happy bears and sad bears. You
    can tell the difference between them by the way
    they hold their hands. Happy bears hold their
    hands high in the air, and sad bears hold their
    hands down low. Happy bears taste sweet and are
    easy to catch. On the other hand, sad bears
    taste bitter, are sneaky, and hard to catch.
    Because of this, you only eat happy bears. New
    bears are born every year during hibernation and
    the birth rate is one new bear for every old bear
    left from last year. The trait of being a happy
    bear is inherited genetically, and it is
    dominant over the trait of being a sad bear.

Simulating Natural Selection
Simulating Natural Selection
  • 2. Obtain a population of 15 bears. You must
    obey the following rules
  • You must have a least 7 happy bears, and at
    least 3 sad bears, but remember that your total
    must add up to 15 bears (i.e. you could have 10
    happy bears and 5 sad, or 8 happy, and 7 sad,
  • 3. Record in Table 1 the following information
    the total population, the number of happy bears,
    and the number of sad bears.
  • 4. Make a prediction on what do you think will
    happen to the happy and sad bear populations over
    time. Write the prediction in the Data Sheet on
    page 5.

Simulating Natural Selection
  • 5. Now the monster (you) will catch bears. You
    will eat 3 happy bears and 1 sad bear (I know
    that sad bears are bitter and hard to catch, but
    sometimes you might catch one or one might die of
    natural causes. This is why you will eat a sad
    bear to represent those sad bears that get caught
    or die.).
  • 6. Now all living bears reproduce (add 1 new
    happy bear for every happy bear still remaining,
    and 1 sad bear for every sad bear still
  • 7. Repeat this two more times for a total of 4

Simulating Natural Selection
  • 8. Determine the percentage of happy bears and
    sad bears for each generation and record these in
    Table 2. Calculate the percent using this
  • For Happy Bears
    For Sad Bears
  •   of Happy Bears x 100 of
    Sad Bears x 100
  • total number of bears total
    number of bears

Simulating Natural Selection
  • 9. Using Microsoft Excel, make a graph of Table
    1 Generations versus the Number of Bears. The
    values for Generations will be on X-axis, while
    the values for the Number of Bears will be on the
  • 10. Using Microsoft Excel, make a graph of Table
    2 Generations versus the Percentage of Bears.
    The values for Generations will be on X-axis,
    while the values for the Percentage of Bears will
    be on the y-axis.
  • 11. Before answering the Analysis questions, make
    sure to clean up your area. Cleaning up is part
    of your lab grade.
  • 12. Answer the Analysis questions located on
    pages 6-7 in complete sentences.

Simulating Natural SelectionTable 1
Generations Number of Happy Bears Number of Sad Bears Total Number of Bears
Simulating Natural SelectionTable 2
Generations Percentage of Happy Bears Percentage of Sad Bears
Simulating Natural Selection
  • Analysis Questions
  • 1. What happened to the number of happy bears
    over time?
  • What happened to the percentage of happy bears
    over time?
  • Were your predictions correct? Explain.
  • What do you think would have happened to the
    happy bear population over time if you had
    started with only 5 happy bears? Be specific!
    Work it out over a few generations to answer the
  • In our scenario, all bears reproduced to make
    like them. In actuality, this would not always
    by the case. Explain why (think about the
    relationship between genotype and phenotype).

Simulating Natural Selection
  • Conclusion
  • Instructions
  • Based upon your knowledge of natural selection,
    as well as what you have just learned in the
    experiment, discuss the effect of a population of
    a particular species over a period of time. Be
    sure to include information supporting the topic.
    Also, include the main points of the lab and the
    results of the experiment. The conclusion will
    be written using correct grammar and sentence

Simulating Natural Selection
  • Once you have answered all questions (Pre-lab and
    Analysis), developed the data tables and graphs
    on Microsoft Excel, and written the essay, hand
    in the laboratory assignment to the teacher for a

Final Assessments
  • Complete the worksheet on Chapter 13, Section 1
    Theory of Evolution by Natural Selection Active
    and Direct Reading.
  • Answer in complete sentences the Chapter 13,
    Section 1 Review Questions on Page 282 of the
    Holt Biology textbook.
  • Study and review the material you were taught for
    your test next class. The test is made up of
    multiple choice, true or false, and short answer
    response questions.