Darwin’s Theory of EvolutionThe Puzzle of Life’s Diversity
Chapter 15-1
WRITE A DEFINITION:
EVOLUTION:
THEORY:
FOSSIL:
change over time; the process by which modern
organisms have descended from ancient organisms
a well-supported testable explanation of
phenomena that have occurred in the natural world
the preserved remains of ancient organisms
evolution
fossiltheory
The _______ that Darwin found caused him to ask questions that led to his proposal of the theory of_________._______ provide evidence to support the theory of_________.
________ is a______; a testable explanation of naturally-occurring phenomena
The _____ record provides for some of the evidence that supports the ______ of evolution
Evolution
theory
fossils
evolutionFossils
evolution
fossil
theory
The total variety of all the organisms in the biosphere
= ________________
Where did all these different organisms come from?
How are they related?
BIODIVERSITY
REMEMBER !
What scientific explanation can account for the diversity of life?
ANSWER:
A collection of ______________,
__________, and ___________ known as
________________________
Scientific facts
observations hypotheses
EVOLUTIONARY THEORY
The person who contributed themost to our understanding of evolution was ______________________
In 1831, at age 22, he joined the crew ofthe _______________ as a naturalist fora ________ voyage around the world.
Charles Darwin
H.M.S. Beagle5 year
During his travels, Darwin wrote thousandsof pages in his journals, drew pictures ofthe things he saw, and collected a vastamount of ______________ that led himto propose a _______________________about the way _____________.
revolutionary hypothesisevidence
life changes
DARWIN WONDERED?
Why do Argentina and Australia have ______________ even though they have ______________________?
Why are there no ______ in Australia andno ________ in England?
Why have so many species disappeared?
How are these ______ species _______ to living species?
different
animals similar grasslandecosystems
rabbitskangaroos
extinctrelated
Who Was Charles Darwin?
While on his voyage around the world aboard the ____________, Charles Darwin spent about one month observing life on the
________________.
There, he encountered some unique animals, such as ______ and ________.
Galápagos Islands
H.M.S. Beagle
finches tortoises
The Galάpagos Islands are close together but have very different _______.
Some were hot and dry, with little vegetation.
Others had more rainfall and were rich in vegetation
Each island hadits own _____ _________ of plant and animal species.
climates
assortment
unique
Pinta IslandIntermediate shell
Pinta
Isabela IslandDome-shaped shell
Hood IslandSaddle-backed shell
HoodFloreana
Santa Fe
Santa Cruz
James
Marchena
Fernandina
Isabela
Tower
Giant Tortoises of the Galápagos
IslandsSection 15-1
On the desert-like Hood Island,
tortoises had long necks…
while on the lush rainforest of Isabela Island, tortoises had
short necks…
and on Pinta Island, tortoise necks were somewhere in
between
After his voyage, Darwin spent a great deal of time thinking about his findings.
He began to wonder if animals living ondifferent islands had once been membersof the ____________ that haddeveloped _________ characteristicsafter becoming _______ from oneanother in different habitats.
same speciesdifferent
isolated
Darwin’s Theory of EvolutionIdeas that Shaped Darwin’s Thinking
Chapter 15-2
Ideas that shaped Darwin’s thinking:
In 1785 ______________proposes that the ______________ by_________________occurring over__________ periods of time, and is_______________ old.
very long
James Hutton
Earth was shaped
geological forces
millions of years
Ideas that shaped Darwin’s thinking:
In 1833 ___________ explains that the geological processes still ___________ have shaped Earth’s features over ________________
Charles Lyell
occurring now
long periods of time
Ideas that shaped Darwin’s thinking:
Theory of Pangaea
…and continentaldrift
Living things must compete for food, shelter, space, mates
competition
REMEMBER !Chapter 3
Ideas that shaped Darwin’s thinking:
_____________________
He observed that babies were being born
faster than people were dying. He
reasoned that if the human population
continued to grow, sooner or later there
would be _______________________
Thomas Malthus (1798)
insufficient space & food
Ideas that shaped Darwin’s thinking:
___________________________was one of first scientists to recognize living things_______________ and thatall species were ________ fromother species.
Lamarck published his hypothesis of________________________ the year Darwin was born.
changed over time
Jean-Baptiste Lamarck (1809)
descended
Inheritance of Acquired traits
The male fiddler crab uses itsfront claw to attract mates andward off predators.
Through repeated use, the frontclaw becomes larger.
The fiddler passes on this acquired characteristic to its offspring
What’s wrong with Lamarck’s hypothesis?
Lamarck didn’t know about
genes and how traits are _______.
If you lifted weights your
whole young adult life, and
then you had children, would
your kids be more muscular?
inherited
NO! Acquired traits may help an organism, but they won’t be passed on to offspring.
What’s right with Lamarck’s hypothesis?
Lamarck was first to
develop a scientific
hypothesis about
_______
and recognize that
organisms are
________________________
evolution
adapted to their environments
a. The earth is really old, and slowly changes
b. Living things pass changes on to their offspring, leading to species changesc. Sooner or later growing populations run out of resourcesd. Living things change slowly over time because of competition for resources,
and pass those changes on to their offspring
Hutton
Lyell
Malthus
Lamarck
Match the letter of the idea with
the man or men who proposed it:
a. The earth is really old, and slowly changes
b. Living things pass changes on to their offspring, leading to species changesc. Sooner or later growing populations run out of resourcesd. Living things change slowly over time because of competition for resources,
and pass those changes on to their offspring
Hutton
Lyell
Malthus
Lamarck
a.
c.
b.
d.
Concept MapSection 15-3
includes
Evidence of Evolution
Physical remains of
organisms
Common ancestral
species
Similar genes Similar genes
which is composed of which indicates which implies which implies
The fossil record
Geographic
distribution of
living species
Homologous
body structures
Similarities
in early
development
Darwin’s Theory of EvolutionDarwin Presents his Case
Chapter 15-3
What do oranges, broccoli, and Butterball turkeys have to do with
EVOLUTION?(Answers to come in this slide show!)
THINK ABOUT IT
After Darwin returned to England in 1836he filled notebooks with his ideasabout _____________ and the processthat he would later call _______.
He did not rush to publish his ideasbecause they ________ with thefundamental scientific ______ of hisday.
He asked his wife to publishhis ideas when he ___.
evolutionspecies diversity
died
disagreedbeliefs
In 1858 another naturalist,
_________________, wrote an
essay describing his work in _______ that
summarized the same ideas _____ had
been thinking about for 25 years!
Alfred Russel Wallace
Malaysia
Darwin
Suddenly Darwin had incentive to publish
the results of his work!
In 1859
____________________
presented _______
and proposed a
________ for evolution
that he called
__________________
On the Origin of Species
evidence
mechanism
NATURAL SELECTION
WHAT IS DARWIN’S THEORY?
_________________ is found
naturally in all populations
GENETIC VARIATION
WHAT IS DARWIN’S THEORY?
______________________
means that members of each species
must ________ for food, space, and
other __________.
STRUGGLE FOR EXISTANCE
COMPETE
RESOURCES
WHAT IS DARWIN’S THEORY?
Some organisms in a ________
are ________ to survive.
population
less likely
WHAT IS DARWIN’S THEORY?_____________________organisms which are better adapted to the environment will ______ and________, passing on their _____.
SURVIVAL OF THE FITTEST
survivereproduce genes
Ability of an individual to ______
____________ in its specific
environment
= ______fitness
surviveand reproduce
Any ___________________ that
increases an organism’s ______________
= _____________ADAPTATION
inherited characteristic
chance of survival
Over time, natural selectionresults in ________ in theinherited characteristics of a __________.
These changes ______ aspecies’ _____ in its environment.
WHAT IS DARWIN’S THEORY?
CHANGES
POPULATION
increase
fitness
____________________________suggests that each species has ___________, with ________,from other species over time.
This idea suggests that all living species are ____________________, and that all species, living and extinct,share a _________________.
WHAT IS DARWIN’S THEORY?
DESCENT WITH MODIFICATION
DESCENDED CHANGES
RELATED TO EACH OTHER
COMMON ANCESTOR
EVIDENCE OF EVOLUTION:
1.________________
2.________________
3. _______________
4. _______________
5. _______________
6. _______________
7. _______________
Fossil recordGeographic Distribution
Homologous structures
EmbryologyDNA
See Natural selection happen
Artificial selection
• ARTIFICIAL SELECTION WORKSIn artificial selection, ____________
provides the _________ through
_________ and _________________
and ______________ those traits that they
find ______.
NATUREvariation
mutation sexual reproduction
humans select
useful EX: We have selected for and bred cows to produce more milk,turkeys with more breast meat, etc.
Breeds of Dogs
Chihuahua – bred from Techichi of Mexico
by Mayans, had religious significance
Saint Bernard – bred by monks around 1050 A.D.to rescue travelers of mountain passes in the
Swiss Alps between Italy and Switzerland
Irish Wolfhound – bred in Ireland to hunt wolves and elk
Dachshund – bred in Germany as earlyas the 15th century to hunt badgers
ARTIFICIAL SELECTION WORKS
How Do We Know Evolution Happens?
2. The Fossil Record –
______ are the _______
_________________
found in layers of rock
in the Earth.
Fossils
of ancient organisms
remains
How Do We Know Evolution Happens?
The layers of rock tell the history of the
_____, while the _____ found within
the rock tell a history of ___.
The fossils are thought
to be the ________ as
the rock they
are found in.
Earth fossilslife
same age
Sea level
Sedimentary rocks form in horizontal
layers.
When part of Earth’s crust is compressed, a
bend in a rock forms, tilting the
rock layers.
As the surface erodes due to water, wind, waves,
or glaciers, the older rock surface
is exposed.
Movement of Earth’s Crust
Fish die inthe ocean
and arecovered insediment.
Over timeand under
increasingpressure,the remains
becomesfossilized
Earthquakes and volcanoes
cause uplifting of the layers of theEarth, taking the fossils along
Fossils ofmarinefish found
on themountain-
sides ofsouthwest
Wyoming,which atone time
was covered
by aninland sea
TRANSITIONAL FOSSILS HAVE BEEN FOUND
If Darwin’s theory is correct you would expect to find ____________ yet _______________ living in a _________ region as they spread into nearby habitats and evolve.
different speciesclosely related
geographic
That’s EXACTLY what we do see!
REMEMBER THE GALAPAGOS TORTOISES?
Little vegetationLong necks
Lots of vegetationShort necks
Intermediate vegetationIntermediate necks
Tortoises adapted to different habitats as they spread from the mainland to the different islands.= DIVERGENT EVOLUTION = ADAPTIVE RADIATION
GALAPAGOS FINCHES
The _____ of Galapagos finches have ______ to eating a _____ of _____.
beaksadapted variety foods
If Darwin’s theory is correct you would also expect to find _______________ living in ________ geographic regionsbut similar habitats becoming ________ as they adapt to ______________.
far apartdifferent species
more alike
That’s EXACTLY what we do see!
similar ecosystems
Whales and sharks have a _____ body designeven though they are very _______ organisms (one is a fish; the other, a mammal)because they have _________________ to living in a _____ environment.
= CONVERGENT EVOLUTION
similardifferent
independently adaptedsimilar
Whales are closely related to wolves, but don’t look or act much like them = divergent evolution
Whales are distantly related to sharks, but look and act morelike them =convergent evolution
Conclusion:The pressure ofthe environmentdrives evolution
4. _____________________HOMOLOGOUS Structures
4. Homologous Body Structures –
Structures, like the limbs of
vertebrates, look very _______,
but are made from the
__________, because
they are made from
the same clump of
_____________ cells
in the _______.
same bones
embryo
undifferentiated
different
Turtle Alligator Bird Mammal
Ancient lobe-finned fish
Figure 15–15 Homologous Body StructuresSection 15-3
4. Homologous Body Structures –
Some _______________________
are _______ and have no useful
function even though they are still
present, like ________in whales and
boa constrictors.
homologous body structures
vestigial
hipbones
Most mammals have a pouch between their small and large intestine that contains bacteria to digest plants called a _____.
In humans the cecumis shrunken and unused.
It is our _________appendix
cecum
Why grow a tail and then lose it?
HUMAN EMBRYO_________________
__________________________________Tail disappears at
has a tail at 4 weeks
about 8 weekstail
Skinks are a type of lizard. In some species, legs have become so small they _______
______ in walking.Why would an organism possess organs ___________________?
One explanation:The ________ is present to make the organ, but_________________ through ______________.If the organ is not vital to survival, then natural selection would not cause its elimination.
no longer
function
gene codechange over timefunction has been lost
little or no functionwith
5. _____________________
________ of many animals with back-
bones are very similar.
Similarities in Embryology
Embryos
It is clear that the same groups of
_____________ cells develop in the
same order to produce the same
tissues and organs of all vertebrates,
suggesting that they all _______ from
a _______________.
undifferentiated
evolved
common ancestor
6. _______________
Similarities in ____ and ________ sequencessuggestrelatedness
Similarities in DNA
PROTEINDNA
Similar _________ suggest an ___________________.
Human- 46 chromosomes Chimpanzee- 48 chromosomes
karyotypesevolutionary relationship
1. ________________________
If you take the two smaller chromosomes apes have that we don’t, and place them end to end, the ______ _______________ to the #2 human chromosome __________________.
BANDING PATTERN MATCHES
bandingpattern is identical
wehave that they don’t
2. ____________________Chromosomes have special sequences called _______ at their ends to protect the strands during replication.
TELOMERES IN MIDDLE
telomeres
2. TELOMERES IN MIDDLE
Telomere sequences are found __________ and _____________________ of human chromosome #2 suggesting it was made by _____ two other chromosomes together.
→
→
→
ALSO IN THE MIDDLEat the ends
fusing
3. _________________
Chromosome #2 has a second _______________________ region
→
EXTRA CENTROMERE
CENTROMEREINACTIVE
Did you ever wonder why dogs and
cats don’t need to eat ________, but
_______? YOU DO
fresh fruit
Fish, amphibians, reptiles, and most
mammals can make their own
_________, but humans need to eat
fresh fruit or they end up with
________.
VITAMIN C
SCURVY
Human DNA contains the gene that
codes for the enzyme to make
vitamin C, but it is ________________.
Guess what other group of organisms
lack the ability to make their own
Vitamin C?
NONFUNCTIONAL
PRIMATES…
which includes
chimpanzees, orangutans,
gorillas, and other apes.
Humans have many other
nonfunctional vestigial genes called
________________.
EX: Humans have more than 99
different odor receptor genes, but more
than 70% of them are ___________.
PSEUDOGENES
nonfunctional
WHY DOES EVOLUTION MATTER NOW?
There is a natural
variation in populations
of peppered moths.
________________
___________________
7.____________________________
EX: Peppered Moths
Can see Natural selection happen
Typica form - lighter
Carbonaria form - darker
Typica
Carbonaria
The ___________ form was the predominant form
in England _____________________________.
Around the middle of the 19th century the ______ form began to appear. It was first reported in 1848. By 1895 98% of the moths in Manchester
were the ____ variety.
In recent years, the burning of cleaner fuels and Clean Air
regulations has reduced the pollution there and the ______ colored moths have increased in numbers.
light coloredprior to the Industrial Revolution
darker
dark
lighter
7.____________________________
EX: Changes in disease-causing microbes that produce new organisms and __________.
_______
___
__________________________
Can see Natural selection happen
Bird flu
Antibiotic-resistant tuberculosis
HIV
new diseases