Download Evolution Notes (review and THEN complete p.8)

inherited characteristic that
Any ___________________
of survival
increases an organism’s chance
______________
ADAPTATION
= _____________
http://www.wildlife-traps.com/skunks.html
http://www.atomtigerzoo.com/photos/images/20060421233733_duckfeet.jpg
http://www.3kitty.org/travelrama/Photos/123-21-4x6.jpg
Similar adaptations can occur in
more than one organism. WHY?
1. Organisms that live in the same habitat
Ex. Plants in the desert have thick
stems
2. Organisms that are related
Ex. All birds have feathers/beaks
Examples
• Sharp teeth and claws for carnivores
• Flat teeth for grinding and chewing
• Moving in large groups is a behavioral
adaptation; it helps protect the members of
the group from predators.
• The thick fur coat of an arctic fox is a
structural adaptation. It helps protect it
against the cold weather.
Examples
• Camouflage
• Mimicry
Adaptations
• Some adaptations involve changes in the
structure of body parts: mimicry and
camouflage.
– Mimicry enables an organism to copy the
appearance of another species.
MIMICRY
– Camouflage is a structural adaptation
that enables an organism to blend in
with its surroundings.
CAMOUFLAGE
http://152.2.81.1/parkproject/harp/Courses/Animal_adaptations_page.html
http://152.2.81.1/parkproject/harp/Courses/Animal_adaptations_page.html
Variation – differences within a
species
Reproduction may be sexual or asexual
1. Sexual – reproduction with fusion of
sperm and egg.
2. Asexual – involves one organism;
produces identical offspring
Variation is a result of mutation and sexual
reproduction
Four Bodies of Evidence
Supporting Evolution
1.
2.
3.
4.
Fossils
Anatomy
Embryology
Biochemistry
A. Fossil Record
1. fossil= preserved trace of a once living thing
2. Determining fossil age: relative dating (a,b) &
radiometric dating (c)
a. earliest(oldest)- lower layers of rock
b. most recent(newest)- upper layers of rock
c. absolute dating uses ( half- life )-the
amount of time it takes for 1/2 of radioactive
element to decay (carbon-14, chlorine 36,
uranium 235)
Fossil Record
• Although there is not a complete
record of ancient life for the past
3.5 billion years, a great deal of
modern knowledge about the history
of life comes from the fossil record.
• The study of fossils provides strong
evidence for evolution.
Hominid skulls
Petrified Trees
Ammonite casts
Fossilized organic
matter in a leaf
Scorpion in amber
“Ice Man”
B. Comparative Anatomy
Anatomy- study of external and internal structures of
organisms
a. homologous structures- body parts of organisms
that have the ( same internal structure )
ex. human arm, bird wing, whale fin, bat wing have
the same # and arrangement of bones
b. analogous structures- body parts of different
organisms that have same function, but different
( structure ); bird's wing and butterfly's wing
c. vestigial structures- parts with no ( apparent use )
appendix, hip bones in some snakes
Anatomical
• Homologous structures
have different function
but the SAME structures.
These similarities
indicates that the
organisms probably had
a common (the SAME)
evolutionary origin.
Anatomical
• Analogous structures have body parts
that are similar in function but different in
structure. These indicate that the
organisms had different yet related
ancestors.
Vestigal Structures
EX.: Wings in
flightless birds
Most mammals have a pouch
between their small and large
intestine that contains bacteria
cecum
to digest plants called a _____.
In humans the cecum
is shrunken and unused.
appendix
It is our _________
http://www.medicalgeo.com/images/appendix.gif
C. Embryology
Embryology – the study of early growth
stages and development of embryos
a. ( Embryos ) of different organisms
look similar to each other.
D. Biochemistry
Biochemistry- study of (organic molecules)
that make up an organism
a. All organisms use DNA or RNA to carry
information.
b. The more ( similar ) the chemical, the
more closely related the organisms.
Similarities in DNA Sequence
Theory of Evolution
A. Evolution
1. Evolution is the ( gradual change of
characteristics over time )
2. Evolution is responsible for diversity
among organisms that exist.
B. Lamarck’s Theories (1744 to 1829
1. ( Law of Use and Disuse ) - organisms
that don’t use a structure will lose it over
time.
The male fiddler crab uses its
front claw to attract mates and
ward off predators.
Through repeated use, the front
claw becomes larger.
The fiddler passes on this
acquired characteristic to its
offspring
Lamarck’s Theory of
Evolution
• Idea called Law
of Use and
Disuse
• If a body part
were used, it got
stronger
• If body part NOT
used, it
deteriorated
B. Lamarck’s Theories (1744 to 1829
1. ( Law of Use and Disuse ) - organisms that
don’t use a structure will lose it over time.
2. ( Inheritance of Aquired Traits )- traits
attained are passed to offspring.
a. blacksmith passing on muscles to offspring
b. giraffes that stretched necks to reach upper
canopies of trees lived to pass this trait to their
offspring; those with short necks ( died )
http://www.geocities.com/arnold_schwarzenegger_pictures/
What’s wrong with Lamarck’s hypothesis?
Lamarck didn’t know about
genes and how traits are
inherited
_______.
If you lifted weights your
whole young adult life, and
then you had children, would
your kids be more muscular?
NO! Acquired traits may help an organism,
but they won’t be passed on to offspring.
Lamarck’s Theory of
Evolution
• Inheritance Of Acquired Traits
– Traits Acquired During Ones Lifetime
Would Be Passed To Offspring
Clipped ears of dogs could be passed to offspring!
Lamarck’s Mistakes
• Lamarck Did NOT Know how traits
were inherited (Traits are passed
through genes)
• Genes Are NOT Changed By
Activities In Life
• Change Through Mutation Occurs
Before An Organism Is Born
C. Darwin’s Theory (1809 to 1882)
1. He sailed on The Beagle (1831-1836) as the
ship's naturalist; visited the (Galapagos
Islands)
2. On the Galapagos Islands, Darwin collected
more than a dozen species of finches, each with
a specialized diet and way of obtaining food.
Close examination of the finches showed that
they all resembled the blue-black grassquit, a
South American finch.
http://images.encarta.msn.com/xrefmedia/aencmed/targets/illus/ilt/T014608A.gif
GALAPAGOS FINCHES
The _____
beaks of Galapagos finches have
adapted
______ to eating a variety
_____ of foods
_____.
3.(The Origin of Species ) his book
provided evidence that organisms
evolved.
Darwin’s theories, though modified, still form the basis of
modern evolutionary theory:
a. (Speciation )- new species emerge as variations
occur in a population over many generations.
b. Competition- organisms compete for limited
resources ( food, water, space )
c. Overpopulation-organisms produce more (offspring)
than can survive
d. ( Natural Selection)- the envirionment is the agent for
selection determining which are helpful or harmful.
e. ( Survival of the Fittest ) states that organisms best
suited to the environment survive while those not suited
may eventually die.
f. ( Reproduction) - individuals with helpful variations
tend to survive and reproduce thus transmitting their
variations to their offspring.
WHAT IS DARWIN’S THEORY?
GENETIC VARIATION is found
_________________
naturally in all populations
http://www3.nationalgeographic.com/animals/images/primary/zebra-herd.jpg
WHAT IS DARWIN’S THEORY?
______________________
STRUGGLE
FOR EXISTANCE
means that members of each species
must COMPETE
________ for food, space, and
other RESOURCES
__________.
http://www.wasatchcomputers.net/gallery/elk_fight.jpg
WHAT IS DARWIN’S THEORY?
Some organisms in a ________
population
less likely to survive.
are ________
http://www.cartoonstock.com/newscartoons/cartoonists/rrs/lowres/rrsn69l.jpg
WHAT IS DARWIN’S THEORY?
SURVIVAL OF THE FITTEST
_____________________
organisms which are better adapted
survive and
to the environment will ______
reproduce passing on their _____.
genes
________,
http://www.poster.net/bedard/bed202.jpg
WHAT IS DARWIN’S THEORY?
Over time, natural selection
CHANGES in the
results in ________
inherited characteristics of a
POPULATION
__________.
increase a
These changes ______
species’ fitness
_____ in its environment.
How Does Evolution Really Work?
The evolution of insecticide resistance is an
example of natural selection in action
Chromosome with gene
conferring resistance
to insecticide
Additional
applications of the
same insecticide will
be less effective, and
the frequency of
resistant insects in
the population
will grow
Insecticide
application
Survivor
Natural Selection - Bacteria
• Organisms are constantly changing to
adapt to their environment. Take a look at
organisms that have been exposed to
antibiotic and pesticides. The organisms
that survive have become selected
because they are physiologically more
resistant.
Imagine that there are 10
bacteria growing on your
hand.
You use Germ-x to clean your
hand everyday.
After 4 days, there are still 3
bacteria on your hands that have
survived.
Is there anything special about
these bacteria?
Yes..they have something about their
DNA that has made them different and
strong enough to survive.
So now what will happen?
Those 3 that are “resistant” will
undergo Mitosis.
And after a week, your hands will be
covered with tons of bacteria that
are ALL resistant to Germ-X. 
The Process of Speciation
Species – Organisms that can breed and
produce FERTILE offspring
Speciation – Evolution of a new species
Reproductive isolation: organisms no longer breed with
each other to produce fertile offspring
a. Behavioral isolation – differences in courtship or
other reproductive strategies that involve behavior.
b. Geographic Isolation – when a physical barrier
divides a population. (lava from volcanic eruptions, sea
level changes, etc.)
c. Temporal Isolation – mating occurs at different times
of the year
Types and Rates of Evolution
A. Types of evolution
1. Adaptive Radiation– a single species or
small group of species has evolved
through natural selection and other
processes into diverse forms that live in
different ways.
(ex. Darwin’s finches – more than a dozen
species evolved from a single species.
Types and Rates of Evolution
A. Types of evolution
2. Divergent - organisms related by a
common ancestor become more distant,
yet share homologous structures (same
internal structure, but different function)
3. Convergent - unrelated organisms
adapt to the same environment and
develop similar physical characteristics,
but have different structures
http://www.flmnh.ufl.edu/fish/gallery/descript/TigerShark/scars.JPG
http://news.bbc.co.uk/2/shared/spl/hi/guides/456900/456973/html/nn1page1.stm
Whales and sharks have a _____
similar body design
different organisms
even though they are very _______
(one is a fish; the other, a mammal)
because they have _________________
independently adapted to
living in a _____
similar environment.
= CONVERGENT EVOLUTION
Whales are closely related to wolves, but
don’t look or act much like them
= divergent evolution
Conclusion:
The pressure of
the environment
drives evolution
Whales are distantly related
to sharks, but look and act more
like them =
convergent evolution
Types and Rates of Evolution
A. Types of evolution
4. Coevolution – two species evolve in
response to changes in each other.
Coevolution
Bumblebees and the flowers they pollinate
have coevolved so that both have become
dependent on each other for survival.
Types and Rates of Evolution
B. Rate of Evolution
1. Gradualism- organisms evolve as a result of
( small adaptive variations ) that eventually
cause reproductive isolation
2. Punctuated equilibrium- long periods of
stability followed by short periods of rapid
change in a species. Typically caused by a brief
major geologic event that causes a change in
the environment ( tornado, asteroid )
PBS EVOLUTION VIDEO CLIPS
Isn’t Evolution Just a Theory?
QuickTime
Who was Charles Darwin?
QuickTime
How Do we Know Evolution Happens?
QuickTime
How Does Evolution Really Work?
QuickTime |
Why Does Evolution Matter Now?
QuickTime
Why is Evolution Controversial
Anyway?
QuickTime