Transcript powerpoint - Humble ISD

Unit 11: Evolution
Unit 11 Quiz: 2/19/16
Unit 11 Test: 2/23/16
History of the Earth
How old is the earth?
• The earth is approximately 4.6 Billion
years old
• Scientists believe that life originated
in the oceans between 3.9 & 3.4
billion years ago.
• How do we know that?
• Paleontologists
– are scientists who study ancient life
• They study Fossils- Evidence of an
organism that lived long ago
Evidence of Evolution
A.
Evidence from Fossils
1. Types: Imprints, molds (impressions),
casts (filled impression), tracks, hard
parts, actual remains.
2. Dating Fossils
a) Absolute Dating1) Radioactive isotopes- C-14 dating
b) Relative Dating
1) Sediments are layed down in
strata
2) Lowest layers are oldest
3) A fossil's position in
undisturbed rock gives its age
relative to other fossils.
Make a time line of earth’s history:
1. Turn to page 374-375
2. Using a meter stick construct a time line
of earth’s history
3. 1 meter = 1 billion years
4. 1 centimeter = 10 million years
5. 1 millimeter = 1 million years
6. Follow the instructions and construct
your timeline
UNIT XI – EVOLUTION
Test Friday 2-24
THE THEORY OF EVOLUTION
The theory of evolution is one of the most
fundamental concepts in Biology. Evolution
Is defined as _________
in a
changes
__________________over
time. The
population of organisms
scientist considered to be the founder of
modern evolutionary theory is
______________.
Charles Darwin
A. History of Evolutionary
Theory
During the 1700s, several scientists
began challenging the idea of a
world in which changes did not
occur. These scientists and their
hypotheses were very important to
Darwin’s work.
A. History of Evolutionary
Theory
Geologists (Hutton & Lyell) first
1. Gradualism - __________________
older
suggested that the planet was much ______
than previously thought; began to find
changes were slowly, but
evidence that _______
constantly taking place.
A. History of Evolutionary
Theory
2. Malthus – Published an essay that had a
huge impact on Darwin. Proposed that
organisms over
____ - reproduce; in other words,
reproduce at a _____
greater rate than resources
can supply
A. History of Evolutionary
Theory
3. Lamarck
Lamarck was one of the first scientists to propose
changes in
a mechanism for evolution; that is, the _______
population
time
a _________
of organisms over _____.
His major
hypotheses included:
3. Lamarck
Cont.
Tendency Toward Perfection – Stated that
organisms were continually changing in
more successfully
order to live
________________.
3. Lamarck
Cont.
size
Use and Disuse – Changes in ____
and/or ______
shape of a structure in an
organism was a response to use or disuse.
grew bigger
Structures used extensively ________
and structures used less frequently
got smaller
__________.
Acquired Traits
Inheritance of ________
Acquired Traits
B. Charles Darwin
(1809 – 1882)
1. Darwin’s History
Darwin’s data was collected on a 5-year
journey around the world on the USS
Beagle
______. He made observations and
collected data throughout the journey.
He used this data to propose a
hypothesis
________ to explain the diversity he saw.
1. Darwin’s History
Cont.
The area that had the greatest impact on
Galapagos Islands due
Darwin was the _________
to the differences he saw in the same
animals living on different islands.
Galapagos
• He began to suspect that populations from
the mainland changed after reaching the
Galapagos.
• Upon his return he talked to animal
breeders & called what they did to direct
breeding to produce offspring with the
Artificial selection
desired traits __________________,
same as what we called selective breeding
last unit.
2. Darwin’s Observations
• Members of a population often vary greatly in
traits
their _____.
parents to offspring
• Traits are inherited from __________________.
more
• All species are capable of producing _____
offspring than environment
_____________________
can support
• Variations that increase reproductive success
will have greater change of being passed on
than those that do not
increase repro. success
3. Darwin’s Theories
Based on his observations and the
hypotheses of other scientists:
• Organisms with favorable ____
traits tend to
reproduce thereby leaving
survive and _________;
more descendents than other individuals
• This will result in an accumulation of these
offspring changing the
traits in the ________,
genetic
original _______make-up
of the population
4. Darwin’s Legacy
• Did not publish his findings for years
• Alfred Wallace – formed identical
hypotheses
___________
based on his research.
Sent his manuscript to Darwin, and finally
Darwin was persuaded to publish his own
conclusions
Origin of Species
• Released “______________”,
still
considered one of the greatest scientific
studies ever
III. THE PRINCIPLES OF
EVOLUTIONARY THEORY
A. Evolution occurs because of natural
selection - a mechanism for change that
occurs when organisms with favorable
_________
characteristics for a particular environment
______, reproduce
________, and pass these
survive
offspring
characteristics on to ________.
III. THE PRINCIPLES OF
EVOLUTIONARY THEORY
B. The ability of an organism to survive
and reproduce in its environment is
fitness
known as ________________.
III. THE PRINCIPLES OF
EVOLUTIONARY THEORY
C. Fitness is based on _____________.
adaptations
An adaptation is any trait that aids in the
survival
reproduction of an organism.
_______ and ___________
on a cactus,
Examples of adaptations are thorns
____________
___________________________________
camouflage
, antibiotic resistance in bacteria
III. THE PRINCIPLES OF
EVOLUTIONARY THEORY
D. As organisms ________
survive and adapt,
speciation may occur. Speciation is
_________
the formation of new species - a group of
breed
similar organisms that _______
with one
fertile offspring….
another and produce ___________
that
is, babies that can make babies
___________________________.
• For speciation to occur population must
diverge & then be reproductively isolated.
• Two types of speciation:
– Allopatric speciation: physical barrier divides
population into two or more:
Abert & Kaibab squirrels of the Grand Canyon
• Ex. ___________________________________
• Sympatric speciation: species evolves
into new one without a physical barrier.
Seen in insects & plant species
F. Isolating Mechanisms: allow for the gene
separate
pools to become ____________
so they
can form a new __________.
species
Reproductive isolation- as new ______
species
evolves, populations become
reproductively
_________________
isolated from
each other.
• Prezygotic- prevents reproductions by making
fertilization unlikely
______________________
because of
geographic, ecological, behavioral, temporal or
other differences.
& Western Meadowlark
• Ex: Eastern
_________________________
have
overlapping ranges & are similar in appearance
but use different mating songs & do not
interbreed.
• Ex: Fireflies- similar species but mate at different
_____________________
times of night
• Postzygotic- when fertilization has
hybrid
occurred but a ___________
offspring
Cannot develop
_________________or
reproduce;
prevents offspring survival or reproduction
• Ex. Mule, liger
III. THE PRINCIPLES OF
EVOLUTIONARY THEORY
G. The failure of an
adapt
organism to _____
to changes in its
environment will
ultimately lead to its
_________
extinction
because of
natural selection
_______________.
III. EVIDENCE FOR EVOLUTION
A. Fossils – Fossils are
preserved bones and traces of organisms
______________________________________
Fossils provide a record of earlier life and evidence
that evolution has occurred.
Fossils also provide evidence about the earth’s
climate
life forms.
_____________
geography, & ______
90%of Earth’s history occurred during the
Almost ____
________________
Time.
Precambrian
Copyright Pearson Prentice Hall
III. EVIDENCE FOR
EVOLUTION
• There are two major classes of traits when
studying transitional fossils: derived traitsnewly evolved features such as feathers,
that do not appear in the fossils of
common ancestors & Ancestral traitsmore primitive features such as teeth &
tails, that do appear in ancestral ones
III. EVIDENCE FOR
EVOLUTION
B. Biogeography- Variations are seen in the
same types of animals based on their
environment
_____________.
In addition, there are
some organisms that live in very different
locations but they have similar
characteristics because
___________________________________
Their envirnoments are similar: ex.
Climate, food sources, ect.
III. EVIDENCE FOR EVOLUTION
C. Comparative anatomy– Scientists use
anatomical studies of different organisms for
evidence of evolutionary relationships.
1. Homologous structures-For example,
appendages that are very ___________
in
similar
structure, but differ in ____________
are known as
function
homologous structures. Examples of
____________
homologous structures are
arm of human, flipper of dolphin, wing of bat
_____________________________________.
III. EVIDENCE FOR EVOLUTION
2. Vestigial Structures - A structure that is
reduced
_________ in function in a living organism, but
may have been used by an ancestor is known as a
vestigial structure. A structure may become
_______
vestigial when an organism changes in form or
behavior. Examples are wings
______________
of ostrich
eyes
on cave fish, human appendix
_______________________________.
III. EVIDENCE FOR
EVOLUTION
3. Analogous structures- Not all similar
features are evidence of common
ancestry. Analogous structures ca be
same purpose
used for the _____________
& can be
superficially similar in construction but are
not inherited
______________
from a common
ancestor. They show that functionally
similar features can evolve independently
in similar environments. Ex wings birds
vs. insects
III. EVIDENCE FOR EVOLUTION
D. Embryology – Similarities in the
structures of developing ________
embryo of
different organisms are considered to
be proof of a close evolutionary
relationship.
III. EVIDENCE FOR EVOLUTION
E. Comparative biochemistry–
Scientists use DNA studies to
determine the evolutionary relationship
between organisms. The more similar
the DNA,
the closer the evolutionary relationship
_______________________________
IV. MECHANSIMS FOR
EVOLUTION
Evolution does not occur in an
individual; instead it refers to
heritable
changes that occur in a
________________
__________ over time. There must be
population
genetic
mechanisms available for ________
changes to occur:
V. MECHANSIMS FOR
EVOLUTION Cont.
A. Mutation – A mutation is a
change
in DNA
______________.
Although mutations
harmful sometimes
are most often _______,
the resulting change in _________
phenotype may
be beneficial to an organism under
certain conditions.
In jaguars, the mutation is dominant hence
black jaguars can produce both black and
spotted cubs, but spotted jaguars only produce
spotted cubs when bred together.
V. MECHANSIMS FOR
EVOLUTION Cont.
gametes
If the change occurs in the ________,
this change will be passed onto the
offspring of that organism. A positive
mutation that provides a survival
advantage is known as an _________.
adaptation
V. MECHANSIMS FOR
EVOLUTION Cont.
B. Diploidy – Most organisms are
diploid, which means
double set of chromosomes
_______________________.
This allows for increased genetic
variation in a population.
Heterozygote Advantage – Seen in
sickle
cell allele
malaria
_______________
and _________.
Recombination – Leads to increased
genetic variation as a result of
crossing over
_____________
during __________
prophase I
of _______.
meiosis
V. MECHANSIMS FOR
EVOLUTION Cont.
C. Gene Flow – Gene flow occurs when
organisms from one community migrate to
alleles
another. This introduces new _________
population which can lead to a
into the _________
change in the genetic make-up of the
population.
V. MECHANSIMS FOR
EVOLUTION Cont.
D. Genetic Drift – This describes a
situation in which change in a
population is magnified because the
population size is very ______.
small
Causes of genetic drift include
V. MECHANSIMS FOR
EVOLUTION Cont.
Bottleneck effect – large portion of
population ______________________
destroyed in disaster
Founder effect – segment of
population moves to new ________
habitat
Simple
illustration
of founder
effect. The
original
population
is on the
left with
three
possible
founder
populations
on the right
IX. MECHANSIMS FOR
EVOLUTION Cont.
• E. Single Gene Traits-Natural selection
single gene traits can lead to changes
on __________
in ______
allele frequencies and therefore to
evolution. EX. _____________________
Color change in a lizard poplution
IX. MECHANSIMS FOR
EVOLUTION Cont.
F. Polygenic Traits-Natural selection can
affect the distributions of phenotypes in 3
ways:
one
• Directional Selection-Individuals at ___
end of the bell curve have higher fitness
than those in the middle or other end.
Birds with bigger beaks are selected for over
EX:_______________________________
Medium & small beaks.
_________________________________
IX. MECHANSIMS FOR
EVOLUTION Cont.
middle
• Stabilizing Selection-Individuals in the ________
have the highest fitness causing the curve to
narrow.
Birth weight, babies in the middle weight range are more
• EX:___________________________________
______________________________________
likely to survive than smaller or larger babies
• Disruptive Selection-when individuals at the ends of the
curve have the higher fitness. If lasts long enough can
ends distinct
cause the curve to split in two and create _____
phenotypes. EX.
Finches beak sizes, large & small beaks are selected for &the medium beak
_____________________________
Struggle to survive.
IX. MECHANSIMS FOR
EVOLUTION Cont.
V. MACROEVOLUTION
• A. Extinction-More than ____%
of all
99
species that have ever lived are now
______,
extinct which means the species has
died out. Darwin proposed possible
reasons with competition for
___________________________
resources & environmental change
Fig. 1: Number of assessed taxa in each species group in Volume 1. For
each species group, the pie chart shows the absolute number of taxa and
that number as a percentage of all taxa (n = 478). By agreement, neobiota
are not included in the analysis.
V. MACROEVOLUTION
Mass extinction has occurred several times,
• ______
wiping out entire __________.
ecosystems
Meteorites , volcanic action, and Tectonic
plate
• _______
___________
movement has been blamed.
evolution
• Mass extinctions clear the way for __________
Mammals
of other species. EX: _________
V. MACROEVOLUTION
B. Adaptive radiation or divergent evolution single species has evolved
the process where a _____
natural selection into diverse forms
through ________________
that live in short period of time that live in different
ways. Often follows mass extinctions EX:
Finches & tortoises of the Galapagos
__________________________
evolution
C. Convergent
_____________________
when unrelated
species evolve similar traits even though they live
in different parts of the world because of similar
ecology & climate. EX:__________________
Mara of South
America & rabbit
of England
X. MACROEVOLUTION
Co-evolution is when a change in one organism
D. ______________
corresponding change in another organism.
leads to a ____________
EX: _______________
Orchid/bee/moth
E. ____________________
Punctuated Equilibrium Equilibrium is another pattern
gradualism punctuated equilibrium is
of evolution. Unlike __________
characterized with long periods of __________
interrupted
stability
by brief periods of ______
rapid change. It is controversial but
known that evolution does occur at different rates.