Title: evolution
1evolution
2evolution
3EVOLUTION
- Change in a population over time.
Does Evolution mean Man comes from Monkey?
4Charles Robert Darwin (1809 1882)
- He was the individual who contributed more to our
understanding of evolution than anyone was else.
- Grew up amidst wealth, comfort, and country
sports - Unimpressive student, thought of becoming a
country physician (like his father) or a
clergyman - FYIborn on the same day as Abraham Lincoln
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- Darwin served as naturalist aboard the H.M.S.
Beagle on a British science expedition around the
world - Traveld from 1831-1836
- During his travels, Darwin made numerous
observations and collected evidence that led him
to propose a revolutionary hypothesis about the
way of life changes over time.
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9HMS Voyage
10Galapagos Islands
11Darwin's Work
- When the ship would anchor Darwin would collect
plant and animal specimens. - He would study and observe these during travel
time at sea. - His curiosity and analytical nature were
ultimately the keys to his success as a scientist.
12Darwin's Work
- His primary focus was on how and why some animals
and plant life were found in some specific areas
but not others that had similar ecosystems.. - Why are there no rabbits in Australia? Why no
kangaroos in England? Even though both habitats
seemed perfect for them! - He also began to study preserved remains of
ancient organisms called fossils. - Why had animals changed so drastically? Why had
some changed very little?
13Darwin's Work
- The Galapogos Islands was a port that influenced
Darwins theories the most. - Several islands that although close together had
very differenct climates. - Darwin worked primarily with tortoises, inguanas
and finches. - He made observations about these and other
animals. - He focused on how these animals were similar to
other species but very unique to the islands.
14INFLUENCES ON DARWIN
- Essay of Population by Thomas Malthus stated
that human population increases faster than the
food supply - Principles of Geology by Charles Lyell stated
that the earth is changing slowly and the forces
that acted on it in the past are still at work
15INFLUENCES ON DARWIN
- 3. Jean-Baptiste Lamarck- He publishes his
hypothesis of the inheritance of acquired traits.
The ideas are flawed, but he is one of the first
to prose a mechanism explain how organism change
over time. - He thought that if an animal somehow altered a
body structure, it would pass that change on to
its offsprings. By exampleif you lifted weights
all the time you could pass on big muscles to
your children.
16INFLUENCES ON DARWIN
- 3. The discovery of fossils in South America
which were similar in appearance to modern
armadillos, but their size indicated they were a
different species. - 4. The Galapagos Island discoveries which showed
the tortoises and finches were slightly different
from island to island, i.e. variations.
17INFLUENCES ON DARWIN
- The use of selective breeding to create new
varieties - Animal and plant breeders were able to create
new organisms by selectively breeding parents for
desired traits.
18 19Isabela Island- Dome-shaped shell
-
- Pinta Island Intermediate shell
Hood Island- Saddle backed shell.
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24Alfred Wallace
- About 20 yrs. after Darwins voyage, another
young Englishman went on a venture to South
America and wrote Darwin a letter outlining a
theory hed been developing - Darwin was astonished, Wallace was describing the
same natural selection that he had been
contemplating for 20 years, but never had the
nerve to publish
25- 18 months later Darwin went on the write On the
Origin of Species by Means of Natural Selection,
or the Preservation of Favoured Races in the
Struggle for Life in 1859 - The Origin of Species
26Darwin's Conclusion
- In his book Darwin proposed the idea of natural
selection to explain how species evolve. - He then presented evidence that evolution has
been taking place for millions of years and still
continutes - His work caused a sensation!!
- But what did he actually say.
27Darwin's Conclusion
- One of Darwin's important insights was that
member of each species vary from one another in
important ways. - He focused on how variations of species
mattersand in fact was used even then.
28Artificial Selection
- Artificial selection- Breeding organisms with
specific traits in order to produce offspring
with identical traits. - Humans have been doing this for years with both
plants and animals.
29Natural Selection
- Darwin was convinced that artificial selection
worked in nature. - Organisms produce more offspring than can
survive. For example fish sometime lay millions
of eggs - In any population, individuals have variations.
(size, color, speed) - Individuals, with certain useful variations, such
as speed or being able to avoid predators, will
survive in their environment, passing those
variations to the next generation. - This is often referred to as Survival of the
Fittest.
30Natural Selection
- Overtime, offspring with certain variations make
up most of the population and may look entirely
different from their ancestors. - Darwin proposed this idea of natural selection to
explain how species change over time.
31Natural Selection
- How is one moth better adapted than the other?
- Which one will survive and pass on its
characteristics to its ofspring?
32Natural Selection
- Peppered Moths
- http//www.youtube.com/watch?vsVVldxxbWig
- http//www.youtube.com/watch?vLyRA807djLc
33Natural Selection
34Natural Selection
35Natural Selection
36Natural Selection
37Divergent Evolution
- Divergent evolution, the pattern of evolution in
which species that once were similar to an
ancestral species diverge, or become increasingly
distinct. - Divergent evolution occurs when populations
adapting to different environmental conditions
changes becoming less alike as they adapt,
eventually resulting in a new species.
38Divergent Evolution
39Divergent Evolution
40Convergent Evolution
- A pattern of evolution in which distantly related
organism evolve similar traits is called
Convergent Evolution - This occurs when unrelated species occupy similar
environments indifferent parts of the world - Because they share similar environmental
pressures, they share similar pressures of
natural selection.
41Convergent Evolution
42BIOLOGICAL EVOLUTION
If Evolution is realhow can we prove it?
- 1. The fossil record
- 2. Anatomical evidence
- 3. DNA similarities
- 4. Embryological evidence
431. FOSSIL RECORDS
- A fossil is any preserved part or trace of an
organism that once lived. - Fossils may be formed when all or part of an
organism is buried before it can be eaten or
before it decays.
44FOSSIL RECORDS
- Fossils are often found in sedimentary rock.
- Sediments such as mud, silt, and sand have
deposited layers on top of one another and are
subjected to great pressure.
45FOSSIL RECORDS
- Fossils are important because they provide a
record of early life and evolutionary history. - Fossils are found throughout the world.
- While many fossil records are incomplete the
sequences of evolution can become more clear.
46Categories of Fossils
1. Imprints 2. Molds 3. Casts 4. Petrified
fossils 5. Intact fossils
47Imprint Fossils
- An imprint fossil forms when an object is pressed
into mud, such as a leaf or insect. - As it slowly dissolves, the mud surrounding it
can harden and a space is left. - A mold of the original object is formed, which
fills with sediment and becomes a fossil.
48Mold Fossils
- Formed when hard body parts such as teeth,
shells, or bones form depressions, that are the
size and shape of the body part, in the rock that
are shaped like the organisms part - The part decomposed and leaves its specific shape
because the sediment had already hardened around
the original part
49Cast Fossils
- Formed when the original materials decompose and
the resulting mold is filled with another
material. - Now think of of something like a bone buried in
sediment. The sediment hardens around the bone,
and the bone rots away, creating a mold. Over
time, minerals fill in the mold and harden,
creating a cast of the bone, or a cast fossil.
50Petrified Fossils
- Formed when the hard parts of an organism are
gradually replaced by minerals
51Intact Fossils
- Occur when an entire organism or part of an
organism is preserved intact - Smaller organisms may be trapped in amber, the
sap of trees - Larger animals have been trapped in tar or ice,
which prevented their decay
522. Anatomical Similarities
- Many evolutionist study the structural
similarities between organisms to determine their
common ancestry.
53Homologous Structures
- Structures with a common evolutionary origin are
called Homologous Structure. - Scientist view organisms with homologous
structures to evolve from a common ancestor.
54Homologous Structures
- Structures that are similar due to evolutionary
origin, such as the forearm bones of humans,
birds, porpoises, and elephants, are called
homologous.
55Homologous Structures
56Analogous Structures
- The body parts of organisms that do NOT have a
common evolutionary relationships origins but are
similar in functions are called Analogous
Structures.
57Analogous Structures
58Vestigial Structures
- Vestigial structures are remnants of once-useful
structures that are no longer used. - Limb bones can be found deep inside the body of a
whale. This shows they once had use for legs. - A snake also has the same type of hind limb bone
remnants. - Humans have a tail bone and an appendix that we
do not use - Horses have toe bones.
- Examples like these can be found in other species
as well.
59Vestigial Structures
60Embryological Differences
- An embryo is the earliest stage of growth and
development of both plants and animals. - Similarities among the young embryos suggest
evolution from a distance common ancestor.
61Embryological Differences
62Embryological Differences
63Embryological Differences
64BioChemistry Differences
- Biochemistry also provides evidence for
evolution. This is probably the MOST convincing
piece of evidence to support Evolution.
Darwinhe didnt have this support. - It reveals information between individuals and
species. - Comparisons of the DNA or RNA of different
species produces biochemical evidence for
evolution.
65evolution
- The great diversity of organisms is the result of
more than 3.5 billion years of evolution that has
filled every available niche with life forms.
66evolution
- Natural selection and its evolutionary
consequences provide a scientific explanation for
the fossil record of ancient life forms, as well
as for the striking molecular similarities
observed among the diverse species of living
organisms.
67evolution
- The millions of different species of plants,
animals, and microorganisms that live on earth
today are related by descent from common
ancestors.
68evolution
- Biological classifications are based on how
organisms are related. - Organisms are classified into a hierarchy of
groups and subgroups based on similarities which
reflect their evolutionary relationships. - Species is the most fundamental unit of
classification.
69evolution
- http//www.youtube.com/watch?vGhHOjC4oxh8
70EVOLUTION
71Variation and Gene Pool
- Lets review just a little.
- Mendel concluded that traits are controlled by
alleles and you must have two for every trait. - Some plants or animals have several different
alleles in their gene pool that determine a
specific trait. (more that 2 choiceslike blood
type. A, B, or O)
72Variation and Gene Pool
- Genetic Variation is studied in populations.
- Populations are a group of the same species that
live together - Because members of the same population interbreed
they share a common group of genes.
- A Gene Pool consists of all genes, including all
different alleles, that are present in a
population. - The Relative Frequency of an allele is the number
of times that the allele occurs in a gene pool. - Example B (black fur) has a relative gene
frequency of 40, while b (white fur) has a
relative gene frequency of 60/
73Genetic Equilibrium
- Genetic Equilibrium- When the ratio of genes in
a population remain constant over a long time. - In genetic terms, evolution is any change in the
relative frequency of alleles in a population. - Remember..evolution does NOT happen to
individuals but rather to populations
74Genetic Variations
- Biologist can explain how variation is produced.
- The two main sources of genetic variation are
- Mutations.
- Genetic shuffling that results from sexual
reproduction. Crossing Over of homologous pairs
during meiosis.
75Genetic Drift
- GENETIC DRIFT When genes in a population change
due to random chance. Disrupts genetic
equilibrium. Usually seen in small populations. - Example Amish population in Pennsylvania.
- Very small population.
- When a young man had a mutation that caused
multiple fingers and short stature. It spread
through the population and caused a change in the
ratios.
76Hardy Weinburg Equilibrium
- This is a condition where there is always balance
in the frequency of genes in a population. - It states that allele frequency in a population
will remain constant unless one or more factors
cause those frequencies to change. (add this) - That means there is never any evolution.
- It has a complicated equation.
77Hardy Weinburg Equilibrium
- In order for the principal to remain constant 5
conditions must be meet - Random Mating
- Large Population
- No immigration or emigration
- No Mutations
- No Natural Selection
78Process of Speciation
- We realized that these 5 conditions cannot always
be metbut when do these lead to the formation of
new species or speciation. - The gene pools for two populations must become
separated for them to become new species. - When the members of two population cannot
interbreed and produce fertile offspring
Reproductive Isolation has occurred.
79Process of Speciation
- Another type of isolating mechanism, Behavioral
Isolation, occurs when two populations are
capable of interbreeding but have differences in
courtship rituals or other reproductive
strategies that involve behavior.
80Process of Speciation
- Geographic Isolation- Two populations are
separated by geographic barriers such as rivers,
mountains, or bodies of water. - Temporal Isolation- Two or more species reproduce
at different times.
81Natural Selection on Polygenic Traits
- Natural selection can affect the distribution of
phenotypes in any of three ways directional
selection, stabilizing selection, or disruptive
selection
82Directional Selection
- Directional Selection- Favors the extremewhen
individuals at one end of the curve have higher
fitness than individuals in the middle or at the
other end.
83Stabilizing Selection
- Stabilizing Selection- favors the average
Individuals near the center of the curve have
higher fitness than individuals at either end of
the curve.
84Disruptive Selection
- Disruptive Selction- small or large are most
successful individuals at the upper and lower
ends of the curve have higher fitness than those
in the center.
85EVOLUTION IN TENNESSEE HISTORY
86The Monkey Trial(Tennessee v. John Scopes)
- The Roaring 20s
- Younger modernists no longer asked whether
society would approve their behavior - Alcoholic prohibition
- Jazz Age
- Babe Ruth
871925
- Worst tornadoes in U.S. history
- Hitler published Volume 1 of Mein Kampf founds
the SS - Capone takes control of Chicago mob
- Pres. Calvin Coolidge takes the Oath of Offfice
- B.B. King, Malcom X, and Paul Newman are born
- In Tennessee
88The Butler Law
- Feb. 1925, Gov. Austin Peay signs The Butler
Law (introduced by John Butler) - making it unlawful to teach any theory that
denies the story of divine creation as taught by
the Bible and to teach instead that man was
descended from a lower order of animals
89Dayton, Tennessee
Above downtown Dayton Right Rhea Co. High School
90Robinson Drug Store
- ACLU advertised to offer services
- to anyone willing to challenge the
- new law
- local group of men saw an
- opportunity to put town on the map
91John Scopes
- 24 yrs. old, from Illinois
- Part-time teacher football coach
- Assigned readings on evolution from Hunters
Civic Biology
92The Case
- Group at drug store (including school
superintendent) summoned Scopes - Scopes showed the men the book he used (drug
store also sold textbooks) and the assigned
reading - Asked Scopes if he would be willing to be part of
test trial Scopes agreed
93The Case
- Friends of Scopes agreed to prosecute, local
attorneys Herbert Sue Hicks - John Neal, law school dean from Knoxville drove
to Dayton, volunteered to defend Scopes - William Jennings Bryan heard about the case and
went to assist prosecution - Clarence Darrow heard about case and Bryan, so he
went to assist defense
94William Jennings Bryan
- The Great Commoner
- 3-time Democratic Pres. candidate
- Sec. of State under Woodrow Wilson
- Had been leading crusade to banish Darwin from
American classrooms
95Clarence Darrow
- Perhaps the most famous American lawyer of 20th
century - Well known for defending labor leaders and
radicals, as well as high-profile murderers - Leopold-Loeb wealthy Chicago teens murdered
schoolmate Darrow helped them escape death
penalty - agnostic
96TRIAL HIGHLIGHTS
- Town had carnival-like atmosphere
- 6 blocks around courthouse became Monkeysville
- - preachers, carnival games, live monkeys
97- watched world-wide by radio and newspapers
(WGN)
98- Nearly 1,000 people (300 standing) packed
courtroom on 1st day, July 10
99Above Rhea Co. courthouse
Top right Judge John T. Raulston
Right judge jury
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108http//www.pbs.org/wgbh/amex/monkeytrial/index.htm
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110- The monkey trial also inspired music -- humorous
songs like "You Can't Make a Monkey Out of Me,"
"Monkey Business Down in Tennessee" and serious
folk songs. Tom Morgan, who lives in the hills
above Dayton, performs songs inspired by the
trial, like this song about John Scopes - Then to Dayton came a manWith his ideas new and
grandAnd they said we came from monkeys long
ago.But in teaching his beliefMr. Scopes found
only griefFor they would not let their old
religion go. - You may find a new beliefIt will only bring you
griefFor a house that's built on sand is sure to
fall.And wherever you may turnThere's a lesson
you will learnThat the old religion's better
after all.
111GOAL OF DEFENSE
- Not win acquittal, but rather to obtain a
decleration by higher court, preferably U.S.
Supreme Court, that laws forbidding teaching of
evolution were unconstitutional - L-R Dudley Field Malone (international divorce
attorney), Scopes, Darrow
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113From left John Scopes, defense attorney Dr. John
R. Neal, and George Rappleyea, manager of the
Cumberland Coal and Iron Co. and one of the
original organizers of events leading up to the
trial.
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115GOAL OF PROSECUTION
- Uphold the Butler Law
- Moral victory for fundamentalism
- Right Bryan
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117Trial Highlights
- On Thurs. July 16, trial was moved outdoors due
to heat, to accommodate crowds, and fear of
courtroom on 2nd floor collapsing - Crowd of 5,000
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119VERDICT
- Jury deliberated for 9 minutes
- GUILTY
- Judge Raulston fined Scopes 100
120RESULTS
- A year later, the Tennessee Supreme Court
reversed the decision on a technicality the fine
should have been set by the jury, not Judge
Raulston - Rather than send the case back for further
action, TN Supreme Court dismissed the case - Court commented, Nothing is to be gained by
prolonging the life of this bizarre case.
121RESULTS
- The Butler Act remained on the books for another
40 years, until the legislature repealed it in
1967. - What happened in the 1960s (related to science)?
122What happened to Scopes?
- Left Dayton and became a petroleum engineer
- Died in 1970
123William Jennings Bryan
- Died 5 days after the trial in Dayton
- After eating an enormous dinner, he lay down to
take a nap and died in his sleep - Darrows comment when told he died of a broken
heart, Broken heart nothing he died of a busted
belly.
Buried in Arlington Natl.Cemetery
124Clarence Darrow
- Practiced law for another 13 years
- Died in Chicago in 1938, at age 80
125- Inherit the Wind starring Spencer Tracy
released in 1960 based on successful Broadway
play received 4 academy nominations, however no
Oscars were won - Based on the trial with names changed