Transcript Evolution - Sewanhaka Central High School District

In your notes,
compare the two
pictures. List at
least three
similarities and at
least three
differences
http://www.youtube.com/watc
h?v=qceHwgTMyKI
The change
of a species
over time….
Millions
of years
the process of change
in the inherited traits
of a population of
organisms from one
generation to the next
Changes in structure,
function and behavior
Theory: An idea
which is supported
by extensive,
repeated
experiments, but
not proven as law.
Why isn’t evolution
a law?
Limited access to
the past
PRESENT DAY
SPECIES
DEVELOPED
(EVOLVED) FROM
EARLIER,
DISTINCTLY
DIFFERENT
SPECIES.
The “evolution” of
Evolutionary
Theories
Lamarck’s Theory:
Stated that
structures appear
because they are
needed,
called the theory of
Use & Disuse
ex. Longer necks in
giraffes
Weismann
DISPROVED the
theory that stated
that acquired traits
can be passed on to
the next
generation.
Charles Darwin
“The Father of
Evolution”
WHO WAS CHARLES DARWIN?
*GREW UP IN ENGLAND.
*LEFT MEDICAL SCHOOL AT 17 YEARS OLD
*BECAME A CLERGYMAN & NATURALIST AT
THE AGE OF 22.
*SAILED ON THE H.M.S. BEAGLE IN 1831.
*PUBLISHED THE ‘ORIGIN OF SPECIES’ IN
1859.
HOW DID DARWIN START?
GALAPAGOS ISLANDS
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AMERICA
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ANTARCTICA80
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Darwin wrote about the
differences between the
European animals and plants
compared to their counterparts
in South America, Australia &
Africa.
These observations, and his
readings of other scientific novels,
led Darwin to doubt his religious
background about the origin of the
Earth.
Originally Darwin’s ideas were
referred to as………………
1859
wrote book titled
“Origin of the Species”
Key Concepts
1. Species present now
were not created in
present forms instead
they evolved from
ancestral species
2. Natural Selection:
causes evolution
States that only
those organisms
containing the best
variations can
survive and
reproduce in a
given environment
The overall changes in the population of mice
can be explained best by
1.natural selection
2.succession
3.reproduction
4.mouse extinction
According to the theory of biological
evolution, most present-day species
of organisms
1.
2.
3.
4.
developed from similar, smaller prehistoric organisms
have always existed in the form they have today
developed from fossils of the other organisms
descended from earlier, different species of organisms
In a sexually reproducing species,
evolution could occur as a result of
1. modification of genes in body cells
2. modification of genes in sex cells
3. increased reproduction among individuals with
identical chromosomes
4. recombination of genes in cells reproducing by
mitosis
Individuals who
survive are the ones
best adapted to exist
in their environment
due to the possession
of variations to
maximize their
fitness.
Overproduction
Competition
Variations
Adaptations
Survival of the Fittest
Natural Selection
Speciation
Formation of a
new species due to
favorable
adaptations
gradually
accumulating,
while unfavorable
adaptations
gradually
disappear
Any organisms
which can:
1. Interbreed
2. Produce
fertile
offspring
3. Under
natural
conditions
• Darwin observed 13 species of
finches on the Galápagos Islands
that were similar except for
differences in body size, beak
shape, and eating habits.
• He also noticed
that all finches
were similar to
1 finch he saw
on the South
American
coast.
• Darwin reasoned that the Galápagos
finches must have had to compete
for food.
• Finches with beak shapes that let
them eat food survived longer &
reproduced more than finches
without those beak shapes.
• After many generations, these
groups of finches became separate
species.
The differences seen in the beaks of the four
species of finches are most likely the result of
1.gene expression and asexual reproduction
2.variation and natural selection
3.migration and the need to adapt
4.heredity and a diet of seeds
Other than having a variation in beak
characteristics, describe another variation in
a finch species that could promote survival
of an individual bird. Support your answer.
A person has been arrested on the charge
that he robbed $50,000 from the First City
National Bank last night.
What must the district attorney do to
prove that this man is the robber?
Evidence is essential for all scientific
studies, theories, and laws.
In science …evidence is accumulated
through observations of phenomena
that occur in the natural world, or
which are created as experiments in a
laboratory.
Scientific evidence usually goes
towards supporting or rejecting a
hypothesis
Is the sum total of all the
fossils discovered and
undiscovered and their
placement in sedimentary
rock layers
Fossils are the mineralized or
otherwise preserved remains or traces
(such as footprints) of animals, plants,
and other organisms
Ancient Giant Turtle Fossil
Revealed
• Picture a turtle the size of a Smart car, with a shell large
enough to double as a kiddie pool. Paleontologists from North
Carolina State University have found just such a specimen –
the fossilized remains of a 60-million-year-old South American
giant that lived in what is now Colombia. The turtle in
question is Carbonemys cofrinii, which means “coal turtle,”
and is part of a group of side-necked turtles known as
pelomedusoides. The fossil was named Carbonemys because
it was discovered in 2005 in a coal mine that was part of
northern Colombia’s Cerrejon formation. The specimen’s skull
measures 24 centimeters, roughly the size of a regulation NFL
football. The shell which was recovered nearby - and is
believed to belong to the same species - measures 172
centimeters, or about 5 feet 7 inches, long. That’s the same
height as Edwin Cadena, the NC State doctoral student who
discovered the fossil.
TYPES OF FOSSILS
a.Cast/mold fossils
the original remains of the
organism have been
completely dissolved or
otherwise destroyed
b. True form fossils …
remains of the actual animal
or animal part
c. Trace fossils
…….are the
remains of track
ways, burrows,
eggs and eggshells,
nests, droppings
and other types of
impressions.
d. RESIN FOSSILS …..
Resin is an excretion
of certain plants for
protection
But….
When an organism gets
caught, whole organism
preservation occurs
These fossils can be
best used to provide
information that could
be used in a study of
1.evolutionary relationships
2.dynamic equilibrium
3.selective breeding
4.cell specialization
is the study of similarities and
differences in the anatomy of
organisms.
Structure and form
a. Homologous
structures
•body parts which
are similar in
different species
•
•they may or may
not perform the
same function.
•An example is the
forelimb structure
shared by cats and
whales.
Anatomy
whose bones are they?
HOMOLOGOUS
STRUCTURES
are evidence that a
common ancestor
exists for the
organisms being
studied
The leaves of an oak (left) and the leaves of a gingko (right) are
homologous — they were both inherited from a common ancestor
with leaves.
The wing of a dragonfly (left) and the wing of a
butterfly (right) are homologous — they were
both inherited from an ancient flying insect.
b.Analogous structures
•are structure that are
similar in different
organisms because they
evolved in a similar
environment
•They usually serve the
same or similar
purposes
•An example is the
torpedo body shape of
porpoises and sharks
c. VESTIGIAL STRUCTURES
describes homologous traits of organisms
which have lost all or most of their original
function in a species through evolution
study of comparative
developmental anatomy
is the study of differences in chemical
(metabolic) processes among species
EXAMPLES
DNA AND
CHROMOSOMES
IS THE STUDY OF DIFFERENCES IN CELL
STRUCTURE, COMPOSTION AND FUNCTION