Download I. Developing the Theory of Natural Selection

CHAPTER 15: EVOLUTION
SECTION 15.1: Darwin’s Theory of Evolution
MAIN IDEA: Charles Darwin developed a theory of evolution based on natural selection.
I.
Developing the Theory of Natural Selection
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A.
What is the name of the ship Darwin was on?
What date did the ship set sail?
What is the average age that most people thought Earth was?
Darwin on the HMS Beagle
1.
2.
3.
4.
5.
6.
7.
B.
The Galapagos Islands
1.
2.
3.
4.
5.
6.
7.
C.
What was the primary mission of the ship’s voyage?
What was Darwin’s role on the HMS Beagle?
What was Darwin’s job on the expedition?
What degree did Darwin graduate with?
What are two other disciplines Darwin studied?
How many years was the HMS Beagle was out to sea?
Which four types of things did Darwin collect?
When did Darwin arrive at Galapagos Islands?
Where are the Galapagos Islands located?
Which type of rock are the islands mostly comprised?
How many islands did Darwin visit in the Galapagos?
What major observation did Darwin make about creatures on the different islands?
Which species do the Galapagos finches most closely resemble?
How did the first organisms reach the Galapagos Islands?
Darwin continued his studies
1. What was Darwin’s first hypothesis after analyzing Galapagos finches?
2. What type of animal breeder did he turn to for answers?
3. What new term did Darwin apply to the action of selective breeding?
D.
Natural selection
1. What job was held by Thomas Malthus? economist
2. What is the theory about populations developed by Malthus? if no env’t constraints,
it’ll overpopulate
3. What is Darwin’s rephrasing of Malthus’ theory? always a struggle for survival
4. What are the four basic principles of natural selection?
a. variation
b. heritability
c. overproduction
d. reproduction advantage
5. What two-word term did Darwin labeled his theory? natural selection
6. Analyze Figure 15.3: Read the captions and describe the sunflower example given for
each principle
a. we all look different
b. inherit from parents
c. make lots of babies
d. babies fill & survive in env’t
II.
The Origin of Species
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Which year did Darwin formulated his idea of natural selection? 1840
Give two concepts explained in his first book natural selection & evolution
Name one other contemporary naturalist of Darwin’s time Wallace & Malthus
Give the page in Origin of Species upon which Darwin used the word evolution last page
How do today’s biologists use the term evolution gradual change from ancestors
SECTION 15.2: Evidence of Evolution
MAIN IDEA: Multiple lines of evidence support the theory of evolution
I.
Support for Evolution
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A.
What is the title of Darwin’s most famous book? Origin of Species
What does a theory provides? explains for natural selection & evolution
What does the Theory of Evolution state? all creatures descended from common ancestors
The fossil record
1. Give 2 reasons the fossil record is an important source of information? shows how
species change; shows common ancestors
2. What did Darwin predict about fossils? show links between ancient & current
3. What is a ‘transitional fossil’? (missing) links show change
4. Give one example of a transitional fossil Archeopteryx (part lizard, part bird)
5. Name the two major classes of transitional fossil traits derived & ancestral
6. What ‘are derived traits’? newly evolved from existing Sx (feathers)
7. What ‘are ancestral traits’? primitive Sx seen in ancestor (teeth & tails)
B.
Comparative anatomy
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1.
Where does the evolutionary theory suggest answers may lie? shared ancestry
Homologous structures
a. What are homologous structures? similar Sx common creatures
b. What does evolution predict about body parts? modified from ancestors
c. Give one example of homologous structures forelimbs of vertebrates
2.
Vestigial structures
a. What is a vestigial structure? smallest, non-Fx
b. Give 3 examples of vestigial structures (from table 15.2) snake pelvis, ostrich
wings, human appendix
3.
Analogous structures
a. What is an analogous structure? same Fx; unrelated creatures
b. Give one example of analogous structures shark & dolphin fins
C.
Comparative embryology
1. What is an embryo? pre-birth stage of creature
2. What are two homologous structures all vertebrate embryos have? tails & gills
3. What is suggested by the shared features in embryos of different creatures? common
ancestor
D.
Comparative biochemistry
1. What does the evolutionary theory predict about common molecules? closely related
species have similar macromolecules (proteins, fats, carbs)
2. Name two molecules shared by all living things DNA & RNA
3. What might organisms with closely related molecules exhibit? some same proteins,
hormones
E.
Geographic distribution
1.
2.
3.
4.
Where was Darwin when he first thought about evolution? So. Amer
What is a ‘mara’? SA rodent (looks like a rabbit)
What is a ‘niche’? role/ job
Why did Darwin believe the mara wasn’t closely related to English rabbits? different
structures & functions
5. What types of ‘movement’ patterns did Darwin studied? migration
6. Why are plants better able to migrate across waterways than animals? carried by wind
& water
7. Two things a Biogeologist might study while investigating evolution and fossils
climate, geologic forces (plate techtonics)
II.
Adaptation
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A.
Why didn’t Darwin study biochemistry? not well developed
What lies at the heart of Darwin’s theory of evolution? adaptation
Types of adaptation
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1.
What is ‘adaptation’? changes that make creature more ‘fit’
Fitness
a.
b.
c.
d.
2.
Camouflage
a.
b.
c.
d.
3.
What does fitness measure? how well babies go on to reproduce
What is often counted when determining fitness? # of surviving babies
What increases a creature’s chances of survival? adaptation
What did Darwin looked at (in finches) when comparing islands in the
Galapagos beaks
What is a ‘morphological adaptation’? body structure changes
What does camouflage help creatures do? blend in
What is the ultimate reward for a well-camouflaged creature? reproduction
One example of camouflage tiger stripes, snake skin
Mimicry
a. What does a creature attempt to do if adapted for mimicry? copy env’t Sx
b. What is the ultimate reward for a mimicking creature? reproduction
c. Give one example of mimicry walking sticks, Monarch butterfly, leaf hopper
4.
Antimicrobial resistance
a. What have bacterial species developed from too much antibiotic use? resistance
to antibiotics
b. Give one example of a resistant microbe some bacterial STDs
B.
Consequences of adaptations
1.
Spandrel example (no test questions on this )
2.
Human example

Why are normal human babies born helpless and underdeveloped? larger ones
can’t fit in mother or through the pelvis
SECTION 15.3: Shaping Evolutionary Theory
MAIN IDEA: The theory of evolution continues to be refined as scientists learn new information.
I.
Mechanism of Evolution
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What is the central theme in Darwin’s Theory of Evolution? natural selection
Two things natural selection explains adapting to env’t & variations in a species (like beaks)
In the scheme of classification, at what level does evolution occur? species (breeding
individuals in a population)
A.
variation
increases the
chance that at
least some
members of a
population
will survive a
catastrophic
environmental
change (like a
single food
source
disappearing)
B.
Population genetics
1.
Hardy-Weinberg principle
a. What is an ‘allele’? inherited trait/ genetic material on a chromosome
b. What causes a population to be in genetic equilibrium? few (or no) mutations of
alleles; no variations in species
c. Give one example of genetic equilibrium (e.g. owls) only 1 or 2 colors are seen
in a population of owls; human skin color may reach equilibrium in a few
hundred years (middle-eastern tone)
2.
Conditions
a. What 5 conditions are present for genetic equilibrium to exist in a population?
(1) no genetic drift; (2) no gen flow; (3) no mutations; (4) random mating; (5)
no natural selection (no evolution)
b. These 5 conditions are known to be mechanisms for what? evolutionary change
(or lack of)
c. Which of the 5 conditions is thought to promote adaptation? natural selection
Genetic drift
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1.
What is meant by genes ‘drifting’? change in alleles that cause traits to become more
rare (even disappear); EX: 6 fingers and toes in humans; third eyelid in humans
Founder effect
a. What happens to a small population in ‘founder effect’? small population is
separated from larger one
b. What does this small population carry with it? genetics
c. What might result from a ‘founder effect’? new variations
d. Give one example of Founder Effect in the US. 6-fingers & toes, plus
dwarfism, appearing in Amish & Mennonite populations
2.
Bottleneck
a. What happens to a population during ‘bottleneck’? sm. pop’n becomes almost
extinct (losing a lot of variation)
b. What happens to genetic diversity during bottleneck? inbreeding in a
population results in recessive genes becoming more frequent
c. Give one example of bottleneck in Africa. cheetahs (fertility has become greatly
diminished)
C.
Gene flow
1. How much gene flow is experienced during genetic equilibrium? none (no mutations)
2. What happens to genetic variation with high gene flow? mixing of genes reduces odd
extremes in traits
D.
Nonrandom mating
1. Where do creatures usually find their mates? locally; within a ‘territory’
2. What is favored/ promoted by the inbreeding of a population? homozygous traits
(whether recessive or dominant); EX 6-fingers & toes in humans
E.
Mutation
1. What does ‘mutation’ refer to? random change in chromosomes
2. What is violated by frequent genetic mutations? equilibrium (that status quo)
F.
Natural selection
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What are two things natural selection acts to do? (1) select individuals best adapted for
survival and reproduction; (2) change allelic frequency
1.
Stabilizing selection
a. What does ‘stabilizing selection’ act to eliminate? extreme phenotypes not
suited to the environment
b. Give one example of this average weight of babies
2.
Directional selection
a. In which direction does ‘directional selection’ take a genetic trait? toward an
extreme/opposite trait
b. In peppered moths, what was the ‘extreme’ direction? dark color
c. What caused the darker phase of peppered moths to gain an advantage over the
lighter-colored phase? blend in with soot-covered trees (caused by Industrial
Revolution in Europe)
d. What is now reversing this trend in peppered moths (back to favoring lighter
moths)? controls & laws on pollution
3.
Disruptive selection
a. What happens to a population during ‘disruptive’ selection? splits into two
groups
b. After the ‘average’ trait begins to die off, what traits are left? extreme opposites
c. Why do the northern water snakes have two ‘extreme’ populations? different
habitats caused different skin colors (rocky shore snakes = grey; grassy shore
snakes = mottled)
4.
Sexual selection
a. What might you notice about the males and females in a population
experiencing ‘sexual selection’? they look very different
b. Give one example of sexual selection in birds peacock feathers on male; antlers
on male deer
II.
Reproductive Isolation

A.
What is prevented during reproductive isolation? gene flow and mixing of traits
Prezygotic isolation
1.
When does prezygotic isolation occur? before fertilization (egg & sperm never
meet); EX: some animals have breeding ‘seasons’
2.
What prevents the Eastern and Western meadowlark birds from interbreeding?
different mating songs
B.
Postzygotic isolation
1.
When does postzygotic isolation occur? after fertilization (hybrid is sterile)
2.
What is a ‘liger’ considered an example of postzygotic isolation? can’t produce
offspring; mules are another example
III.
Speciation

A.
What two things must occur for a population to experience ‘speciation’? (1) divergence; (2)
reproductive isolation (of a small population)
Allopatric speciation
1. What causes a population to diverge in ‘allopatric speciation’? physical barrier
2. Give three examples of barriers that might cause allopatric speciation. mountains,
canyons, deserts, oceans, waterways, lava flows
B.
Sympatric speciation
1. How is sympatric speciation different from allopatric speciation? no physical barriers,
they just evolve different traits while living in same environment (different foods,
levels of the forest canopy, layers in a deep lake, etc)
IV.
AMNIOTIC
EGG
allowed
aquatic
ancestor to
move onto
land
Patterns of evolution
A.
Adaptive radiation
geologic time periods are determined by GEOLOGIC or
PALEONTOLOGIC event e.g. mass extinctions due to climate change
1. What is another name for adaptive radiation? divergent evolution
2. What might cause a species to diverge? extinctions; predators or food source
disappears
3. Give one example of an adaptive radiation seen in fish in Sweetwater Park lake: catfish
feed on bottom, trout & bass in deep, cool water, brim & guppies feed at surface
B.
Coevolution
1. What happens to two different species in ‘coevolution’? become adapted to living in a
close relationship (good or bad)
2. Give one example of coevolution mutualism, predator/prey, parasitism; endosymbiosis
C.
Convergent evolution
1. What happens to two different species in ‘convergent’ evolution? evolve similar traits
due to similar environments (but different continents)
2. Give one example (from Table 15.4) of convergent evolution. wolf & Tasmanian devil
(dogs); live on separate continents but have developed similar features; Also…
echolocation in some whales and bats; body shapes of a snake vs a worm
D.
Rate of speciation
1. What rate of speciation is seen in ‘gradualism’? small, gradual changes over
thousands/millions of years
2. What rate of speciation is seen in ‘punctuated equilibrium’? short, rapid changes
followed by long periods of little (or no) change
CLADOGRAMS = branching diagrams much like
a family tree; shows ancestral species and closest
relatives.