Biology Chapter 15

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Biology Chapter 15

• Evolution Unit
• Darwins Theory of Evolution

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IQ 1 Darwins Dangerous Idea

1. How long was Darwin on the Beagle?
2. What Island chain did he study?
3. What trait of finches did he observe variation
   in?
4. What theory did Darwin come up with?
5. Why will the best adapted organism continue to
   populate the earth?
6. What selects which organism will survive
   according to Darwin?
7. What do all organisms compete for?
8. Was Darwins theory well accepted at the time?
9. Can viruses adapt like organisms? What example is
   used to support this in the video?
10. What is an example of a complex structure
    developing slowly over a long period of time as
    shown in the video?

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15-1 The Puzzle of Lifes Diversity

• I. Background Evolution and Its Core Principles
• Evolution is a
• T. Zobzhansky Nothing in biology makes sense
  except in the light of evolution.

Central theme in biology
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B. Core principles of evolution

• 1. All life is linked through a
  ___________________
• 2. Populations of living things
  ___________________ (evolve).
• 3. The _______________________
• this change (natural selection) so
• that advantageous traits are selected over less
  advantageous traits.
• 4. The _________________________________
  ____________________________________ (descent
  with modification).

Common ancestor
Change over time
Environment influences
advantageous traits become more
common in the population
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II. Voyage of the Beagle

• A. A sea voyage helped ____________________
• 1. Darwin was born in England on February 12,
  1809.
• 2. Set sail on the HMS Beagle from England in
  1831 for a ____________ around the world.

Darwin frame his theory of evolution.
5 year voyage
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Darwins Journey
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Tortoise
Marine Iguana
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3. Darwins Observations
Patterns of Diversity

• a. ___________________ plants and animals
  seemed remarkably well suited to whatever
  environment they inhabited.

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Living Organisms and Fossils

• b. ____________________________ Many of the
  fossils that Darwin discovered resembled living
  organisms but were not identical to them.
• For example, glyptodon, an extinct animal, is
  an ancient relative of the armadillo of South
  America. (page 370)

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c. The Galapagos Islands

• 1.) Located 1000 km west of South America.
• 2.) Islands were close together but had
  _________________
• 3.) Hood Island had __________________.
  Tortoises on this island had _____________ and a
  curved shell allowing them to reach the sparse
  vegetation.
• 4.) Isabel Island had _________________.
• Tortoises on this island had
  _____________ and a dome-shaped shell.

different climates
sparse vegetation
long necks
rich vegetation
shorter necks
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Giant Tortoises of the Galápagos Islands
Section 15-1
Pinta
Tower
Marchena
Pinta IslandIntermediate shell
James
Fernandina
Santa Cruz
Isabela
Santa Fe
Hood Island Saddle-backed shell
Hood
Floreana
Isabela Island Dome-shaped shell
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• 5.) Galapagos Finches striking correlation
  between form of finches and the environment they
  inhabit

similarities and differences with mainland species
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Beak Adaptations
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Small Tree Finch
Large Ground Finch
Woodpecker Finch
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15-2 Ideas That Shaped Darwins Thinking

• I. Evolutionary Thinking before Darwin
• A. ________ believed that species were fixed
  and did not evolve.
• B. All species were created in a single act of
  creation about 6,000 years ago.
• C. Buffon (mid-1700s) suggested that
  _______________________ and raised the
  possibility that different species
  ______________________________

Aristotle
Earth was much older
arose from common ancestors.
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II. An Ancient Changing Earth

• Hutton (1785)
• ________________
• ________________
• ________________
• 2. Earth is much older than a few thousand years.

Geological processes operate extremely slowly.
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• B. Lyell (1833)
• 1. Wrote Principles of Geology.
• 2. Promoted the idea of

continual, gradual, consistent geological changes.
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• C. Lamarck (1809) was the
• 1. Believed organisms acquired or lost certain
  traits during their lifetime.
• Example giraffe
• 2.
• therefore, this led to a change in a
  species.

first to support the idea of evolution.
Traits could be passed to offspring
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Example Giraffe
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• D. Malthus (1798)
• 1. If human populations _______________, it
  would lead to competition for scarce resources,
  and
• 2.

increase too fast
only some individuals would survive.
Limits to population growth.
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• E. Wallace (1858)
• 1. Conceived of essentially the same theory as
  Darwin.
• 2.

Speculates on evolution by natural selection.
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15-3 Darwin Presents His Case

• I. Publication of
• On the Origin of Species
• A. Wallaces letter outlining basic principles
  of natural selection spurs Darwin into taking his
  ideas public.

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B. After much fierce debate,
Darwin publishes his theory in 1859.

1. Contains a well-constructed
2. Backed by
3. He used the phrase
4. The book is sold out in one day.

argument for natural selection.
considerable evidence.
descent with modification.
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• C. Advances in genetics in the twentieth century
  yield the mechanism through which natural
  selection operates, vindicating Darwins ideas.

DNA Fingerprinting
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II. Inherited Variation and Artificial Selection

• Nature provided the variation,
• B. Variation existed both in nature and in
  farms. This variation was inherited.
• 1. Cows that __________________________ were
  selected by breeders.
• 2. Plants that __________________________
  were selected.

and humans
selected those variations that they found useful.
produced the most milk
produced the largest and most
flavorful fruit
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Artificial Selection Dogs
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Artificial Selection Plants
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III. Evolution by Natural Selection

• A. The Struggle for Existence
• 1.
• would force organisms to
  compete.
• 2. Result
• or better protected, such as a porcupine can
  
  . Those predators that are faster or have a
  better mechanism to catch prey survive.

High birth rates and a shortage of lifes basic
needs
Those prey that are better camouflaged,
avoid being caught
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B. Survival of the Fittest
ability of an organism to survive and reproduce.

• Fitness
• 2. Darwin proposed that
• 3. Adaptation any _________________
  characteristic that increases an organisms
  chance of survival.

fitness is a result of adaptation.
inherited
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Examples of Adaptations

• a. Waxy coating on the surface of leaves
• prevents against water loss
• Ability to climb trees - spider monkey
• - Tree boa
• Coloration
• - Octopus

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Look closely Its an Insect!

• 4. Those individuals
• and reproduce most successfully. Darwin
  called this process survival of the fittest or

best suited to their environment survive
natural selection.
Mantids exhibit camouflage.
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C. Descent with Modification

• 1.
• 2. Common descent all species
  __________________ were derived from common
  ancestors.
• 3.

All living organisms are related to one another.
living and extinct
A single tree of life links all living things.
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The Tree of Life
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The Tree of Life
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IV. Evidence of Evolution
Evidence Example
1. Fossil Record Fossils the bones, shells, teeth, and other remains of organisms. Fossils of simpler organisms are found in older rocks. Newer strata contain more complex organisms.
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Strata of sedimentary rock at the Grand Canyon.
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Figure 17-2 Formation of a Fossil
Section 17-1
Water carries small rock particles to lakes and
seas.
Dead organisms are buried by layers of sediment,
which forms new rock.
The preserved remains may later be discovered and
studied.
Go to Section
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Formation of sedimentary rock and deposition of
fossils from different time periods.
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Leaf Fossil
Insect in Amber
Ammonites
Dinosaur Fossil
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IV. Evidence of Evolution
Evidence Example
2. Geographic Distribution of Animals 1. All 13 species of Galapagos finches descended with modification from a common mainland ancestor. 2. Similar ecological conditions cause different animals to end up evolving striking features in common.
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Darwins Finches
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The continent of Australia is home to unique
animals, such as these marsupials, that evolved
in isolation.
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IV. Evidence of Evolution
Evidence Example
3. Current Evolution Experimental evidence can demonstrate natural selection at work. Example Peppered moths, antibiotic resistance of bacteria.
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Overuse of Antibiotics has lead to Antibiotic
Resistance in bacteria.
Evolution of Pesticide Resistance in insect
populations.
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IV. Evidence of Evolution
Evidence Example
4. Artificial Selection Humans select from among the naturally occurring genetic variations in species. Example Wheat, corn, cows, race horses, domestic breeding of dogs poodles.
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Evidence Example
5. Comparative Anatomy Similarities in form and structure between otherwise different-appearing structures. Homologous structures Same structure but different function. (organization of bones in fins of whales, wings of bat, paws of cat and gorilla point to their common evolutionary origin) Vestigial Structures Useless structures. (in humans appendix, wisdom teeth, muscles that move the ears and nose.)
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Evolution Evidence Comparative Anatomy

• Homologous structures (homology)
• Descent from a common ancestor
• Vestigial organs Ex whale/snake
  hindlimbs wings on flightless birds

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Comparative Anatomy Whale hind limb Fossilized
leg bones of Basilosaurus, an ancient whale.
A transitional fossil linking past and present.
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Whales are mammals that evolved from land
dwellers.
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Evidence Example
6. Comparative Embryology Early embryo development in all animals goes through similar stages, to the extent of producing structures not seen in adults. Example The fish, bird, rabbit, and human embryos are similar in appearance and all have a two-chambered heart, pharyngeal slits, and a tail with muscles to move it.
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Evolution Evidence Comparative Embryology
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Evolution Evidence Comparative Embryology

• Pharyngeal pouches, tails as embryos

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IV. Evidence of Evolution
Evidence Example
7. Comparative Biochemistry Similarity in genes that control cellular function in very different organisms. Example Same set of genes controls many early events in the development of the fruit fly and mouse. All living things contain DNA.
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Evolution Evidence Molecular Biology

• Similarities in DNA, proteins, genes, and gene
  products
• Common genetic code

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V. Summary of Darwins Theory

• A. Individual organisms
• B. More organisms
• C. Individual organisms
• for limited resources.

differ from one another in a population.
are produced than can survive.
must compete
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A few of the color variations in a population of
Asian lady beetles.
Overproduction of offspring.
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• D. Individuals best suited to their environment
  survive and reproduce most successfully. These
  best fit individuals pass their heritable
  traits to their offspring.
• E. Natural selection, the environment selecting
  the best traits (phenotype) under the current
  conditions, causes species to change over time.

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Final words...

• Absence of evidence is not evidence of absence.

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Workbook AnswersSection15-1

• evolution
• theory
• a, b, d
• Galapagos islands
• true
• a and d
• fossils
• He wondered why so many species had disappeared
  and how they were related to living species.
• Darwin thought that Hood island tortoises had
  curved shells to allow them to reach the sparse
  vegetation on their island, whereas Isabela
  Island tortoises had dome-shaped shells because
  vegetation on their island was more abundant and
  closer to the ground.
• beaks
• Darwin thought how he characteristics of many
  animals and plants, including mockingbirds and
  tortoises, varied noticeably among the different
  islands of the Galapagos.
• Separate species evolved from a common ancestor
  after becoming isolated from one another on
  different islands of the Galapagos.

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Workbook Answers15-2

1. James Hutton and Charles Lyell
2. b and c
3. b, c and d
4. Knowing that Earth could change over time helped
   Darwin believe that life might change as well.
   Knowing that Earth was very old assured Darwin
   that there had been enough time for life to
   change.
5. true
6. true
7. Lamarck proposed that by selective use or disuse
   r organs, organisms acquired or lost certain
   traits during their lifetime. These traits could
   then be passed on their offspring. Over time,
   this process led to change in a species.
8. Lamarck was one of the first to develop
   scientific hypotheses of evolution and to realize
   that organisms are adapted to their environments.
9. Step 3 shows the inheritance of acquired traits.
10. a and b
11. false

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Workbook AnswersSection15-3

1. false
2. Alfred Russel Wallace
3. c and d
4. variation
5. false
6. a, b and c
7. His greatest contribution was developing a
   scientific to explain how evolution occurs.
8. c
9. a
10. b
11. It means that members of each species compete
    regularly to obtain food, living space, and other
    necessities of life.
12. false
13. Individuals that are better suited to their
    environment survive and reproduce most
    successfully
14. a and b

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Workbook AnswersSection15-3

• 15. descent with modification
• 16. common descent
• 17. False
• 18. First-the geographic distribution of living
  species
• Second- homologous structure of living organisms
• Third- similarities in embryology
• 19. They document the fact that life on earth
  has changed over time.
• 20. a
• 21. Darwin thought that such species evolved
  features in common because they were exposed to
  similar pressures of natural selection.
• 22. homologous structures
• 23. true
• 24. vestigial organs
• 25. a, c and d
• 26. Such individuals die or leave fewer
  offspring.
• 27. descent with modification
• 28. They have been confirmed and expanded by
  scientific advances in biology, geology, and
  physics.

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Chapter 15 Assessment p. 389

• 1.c 2.a 3.a. 4.a 5.d 6.b 7.a 8.a 9.c 10 b.
• 11. Evolution, or change over time, is the
  process by which modern organism have descended
  from ancient organisms. Ex. Fastest predators
  passes traits to new generations.
• 12. Darwin observed fossils, some which resembled
  living organisms and others that were unlike any
  organisms he knew organisms seemed well suited
  to their environment.
• 13. Darwins visit to the Galapagos Islands
  convinced him that new species might arise from
  existing species over time.
• 14. Hutton proposed that Earth had to be
  millions, not thousands, of years old. Lyell
  argued that the same forces changed Earth in the
  present as they did in the past.
• 15. Larmarck said that structures that are used
  develop and are passed on to offspring, whereas
  structures that are not used ar not passed on.
• 16. Natural variation provides the raw material
  for natural selection which in turn, leads to
  evolution
• 17. Artificial selection is the process by which
  humans select certain naturally occurring
  variations to use in breeding new plants and
  animals.

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Chapter 15 Assessment p. 389

• 18. Fitness, the ability of an individual to
  survive and reproduce in it s specific
  environment, occurs through ongoing adaptation.
  Ex. An animal survives through camouflage.
  Adaptation is any inherited characteristic that
  increases an organisms chance for survival. Ex.
  Porcupines quill.
• 19. In the survival of the fittest, individuals
  that are best suited to their environment survive
  and reproduce most successfully.
• 20. Descent with modification explains why
  organisms living today may be different from
  their ancestors, for example, by having different
  structures
• 21. Fossils that formed in different layers of
  rock provide evidence of the way species changed
  over time.
• 22. Evidence of evolution in living animals
  includes the existence of unrelated organisms
  from different locations that share traits
  because they evolved form similar environments.
  Beaver in N.A. and Capybara in S.A.
• 23. A vestigial organ is an organ, such as the
  human appendix, that is reduced in size and no
  longer has a function.
• 24. Similarities in embryology of different
  species have been used as evidence that the
  species evolved from a common ancestor.
• 25. Variations occur within populations, and some
  of the variations are favorable. More offspring
  are produced than can survive, and individuals
  with favorable variations are more likely to
  survive. Because of this, changes in the
  population accumulate over long periods of time.