Transcript Chapters 14 & 15

Evolution Web
Activity
XBiology
Chapters 14-15
(Visual Concepts)
Chapter 14 – History of Life
Biogenesis and Spontaneous Generation
1. Compare spontaneous generation
(abiogenesis) to biogenesis.
– Spontaneous Generation/abiogenesis –
living things can arise from non-living
things
– Biogenesis – living things can only arise
from other living things
Chapter 14 – History of Life
Spallanzani’s Experiment and Pasteur’s Experiment
2. Complete the following table.
Scientist
Experiment
Francesco Redi
Tested the theory of spontaneous generation - placed
pieces of meat in two jars—one sealed and one open to
the air. Maggots found only in the control jars that were
open to air because that was the only place where adult
flies could reach the meat to lay eggs.
Lazarro Spallanzani
Tested the theory of spontaneous generation- he boiled
meat broth in flasks and then sealed some of the flasks
and left others open to the air. The broth in the open
flasks became cloudy, while the broth in the sealed
flasks remained clear.
Louis Pasteur
Disproved the theory of spontaneous generation of
microorganisms - curved-neck flasks did not allow
microorganisms to contaminate the broth even though
the flasks were open to the air. When the necks were
broken off, microorganisms were able to reach the
broth, which became cloudy and contaminated.
Redi’s Experiment
Spallanzani’s Experiment

Pasteur’s Experiment
Chapter 14 – History of Life
Radiometric Dating (also Half Life)
3. What is the radioactive
isotope of carbon?
14
What is its half life?
5, 715 years
A student is told that
her fossil contains ¼
the amount of Carbon14 that it originally
had. How old is the
fossil?
2 x 5,715 years =
11,430 years old
Chapter 14 – History of Life
Origin of Eukaryotic Cells
4. How do scientists believe mitochondria and
chloroplasts evolved?
Prokaryotic cells that entered large
prokaryotic cells
Give one similarity that both share with
prokaryotic cells.
Circular DNA, divide like bacteria
Chapter 14 – History of Life
Endosymbiosis
5. What is endosymbiosis?
A mutually beneficial relationship in which
one organism lives inside another
6. According to the endosymbiont theory,
eukaryotic cells evolved when a
relationship developed between a small
prokaryotic cell that lives inside of a
larger prokaryotic cell.
Chapter 15 – Theory of Evolution
Evolution and Mass Extinction
7.
What are some causes of mass extinctions? How many
have there been in Earth’s history?
Drastic changes in the environment
•
How many years ago was the extinction of the
dinosaurs? What is thought to have caused this?
65 million years ago (mya)
Drastic changes caused by asteroids colliding with the
Earth caused dust to blacken the sun and the
temperature dropped
9.
What is causing the latest mass extinction? What is so
remarkable about this compared to the previous
extinctions?
Human activity. Species are disappearing faster than
ever before
Chapter 15 – Theory of Evolution
Lamarck’s Theory of Evolution
10. What correct thoughts did Lamarck have
about evolution?
1) Types of organisms change over time
2) New types of organisms are modified
descendants of older types
What incorrect thoughts did Lamarck have?
Traits were acquired through an organism’s
experience or behavior and could be passed
onto offspring. NOT TRUE…acquired
characteristics are NOT inherited.
Chapter 15 – Theory of Evolution
Darwin’s Theories and Natural Selection
11. What was the name
of Darwin’s ship that
he sailed on?
HMS Beagle
12. Briefly describe Darwin’s two main ideas about
evolution:
• Descent with Modification – newer species
are modified descendants of older species
• Natural Selection – organisms best adapted
to their environment are more likely to
survive and reproduce
Natural Selection
Chapter 15 – Theory of Evolution
Adaptation
13. Define evolution.
Process by which populations change over time
14. Explain why a drought on the Galapagos Islands led
to an increase of larger finches with larger beaks.
A drought could cause small, soft seeds to
disappear leaving only large seeds. Larger finches
with larger beaks could eat more and survive longer
reproducing offspring with larger beaks more
suited for their environment. The finches with
small beaks could not eat the large seeds and died
before producing more small beaked birds 
(Competition for resources)
Which of Darwin’s ideas is this a result of?
Natural selection
Chapter 15 – Theory of Evolution
Adaptation continued
15. Explain how the beaks of each of the finches
listed below are adapted to their food sources.
(Finches were all descendants of a common
ancestor finch).
Finch
Ground
Cactus
Warbler
Beak
Food Source
Large & Heavy
Thick, hard seeds
Tough & Like NeedleNose Pliers
Small & Pointed
(like tweezers)
Catus & insects
Insects in
cracks & crevices
Chapter 15 – Theory of Evolution
Fitness
16. Define fitness.
The ability of an organism to survive longer
and reproduce more
17. Using the insecticide example for fitness,
explain how the use of antibacterial soap
and “hand sanitizers” might be a bad idea.
Bacteria that are resistant will survive and
reproduce creating a population of only
resistant bacteria. Hand sanitizers will
then be useless against them.
Chapter 15 – Theory of Evolution
Law of Superposition
18. What is the law of superposition?
The lower the rock layer, the older the
fossil
19. List the layers from
oldest  youngest
(most recent) in the
diagram in this section.
Oldest = A, then B, then C, then D (D is the
youngest)
Age of Fossils
Chapter 15 – Theory of Evolution
Geologic Time Scale
20.How old is the Earth?
4.6 billion years old (byo)
21. What are eras defined by?
Type of animal present
The end of an era is defined by what?
Extinction of those animals
22.What era are we currently in? Cenozoic
Period?
Quaternary
Epoch?
Holocene
Chapter 15 – Theory of
Evolution
Homologous Structures
23.Why is a human arm and
the wing of a bat
considered to be
homologous?
They have similar
structures but with
different functions
Chapter 15 – Theory of Evolution
Analogous Structures
24.Why are the wings of bees and the wings of
birds considered to be analogous?
They have similar function but different
structure (therefore, not related)
What are analogous structures a result of?
Convergent evolution
25.Complete the following statement:
Homologous structures have similar
structure but different functions, whereas
analogous structures have different
structure but similar function.
Chapter 15 – Theory of Evolution
Vestigial Features
26.What is a vestigial structure? Give an
example.
Features that have no function, but
genetically link us to animals who have a
function for these structures
Examples: tail bone, third eyelid, appendix
Chapter 15 – Theory of Evolution
Similarities in Embryology
27. How are early
stages of
vertebrate
embryological
development
evidence of a
common ancestor?
Because they are
so similar to one
another; shows a
common genetic
blueprint (common
ancestry)
Chapter 15 – Theory of Evolution
Similarities in Macromolecules
28.How are macromolecules used as evidence
for evolution?
1) DNA similarities
2) Fossil evidence
3) Homologous structures
4) Embryonic similarities