Download Evolution Change Over Time

8th Grade Science
EVOLUTION
Evolution and Adaptation
Notes
8th Grade Science
January 2016
On the lined sheet of paper in your notes, answer
the following to the best of your ability.
Before
• What is evolution?
▫ I think evolution is…
• What is a Mutation?
▫ I think mutations are…
• What is a „common ancestor‟?
▫ I think common ancestor
means…
What is
evolution?
I. Species – A group of organisms that are able
to produce offspring that are healthy and
capable of reproducing together.
a. Examples of different species:
i.
Humans, blue whales, dogs, dogwood trees, grey
squirrels, white tailed deer, etc.
b. Biological classification: a system which
is used to precisely describe, organize and
classify all the life on Earth.
a. Creating a classification system allows scientists to
examine the relationships between various
organisms and construct evolutionary trees
b. Also referred to as taxonomy.
II. Biological Evolution – a change in the inherited
traits of a species from one generation to the
next.
a. Because every organism has unique DNA,
some organisms within a species are better
suited for certain environmental changes
than others (genetic variation).
i.
Adaptation: inherited characteristic that
increases an organism's chance of survival
ii. Biologic changes: the change in an organism's
genetic makeup, DNA, that occurs through natural
selection of advantageous traits for survival over
an extended period of time
b. Organisms within a species that are not well suited
for a certain environment will not survive.
i.
Natural Selection: process by which individuals that
are better suited to their environment survive and
reproduce most successfully; also called survival of the
fittest
ii.
Watch this BrainPop video on Natural Selection & answer the
questions on your note sheet
1.
2.
What did Darwin notice about the beaks of the finches on each island?
What is the survival of the fittest?
c. The result is that the characteristics of a species
will change when the environment changes.
d. Within a species, the greater the diversity in
phenotypic traits (such as body structures and
characteristics), the greater the chances are for
that species to survive during environmental
change.
e. Geographic Changes: the change in a geographic
area caused by earthquakes, volcanoes, mountains
forming, and other natural phenomena
i. Plate Techtonics Theory: the movement of Earth‟s
continental and oceanic plates have caused changes in climate,
mountains and deep ocean trenches to form and continually
change the shape of Earth‟s crust throughout time
ii. Natural processes and human activities result in
environmental changes
f. If all of the organisms within a species are unable to
adapt to an environmental change, the species will
become extinct.
i.
Extinction – when all of the organisms within a species die in
a relatively short period of time.
ii.
Most species that have lived on the Earth are now extinct
i.
ii.
Some organisms that lived long ago are similar to currently existing organisms, but
some are quite different
Extinction of organisms is apparent in the fossil record
g. Theory of Evolution: the theory that organisms/species
change over time, caused by the natural selection of
advantageous traits for survival in a particular
environment; this theory also proposes that all organisms
evolved from a common ancestor(s)
i. As random genetic mutations occur within an organism‟s
genetic code, beneficial mutations are passed on to the next
generation
III. Scientists who studied evolution
a. Gregor Mendel “Father of Genetics”
i.
Studied how traits were passed from one generation to the
next in pea plants.
b. Charles Darwin “Father of Evolution”
i.
ii.
Studied how organisms within a species change when they
move to new environments.
Traveled to the Galapagos Islands and observed natural
selection at work when he studied the iguanas, finches, and
tortoises.
IV. Proof that organisms change over time
a. Fossils – prove that the types of organisms on
Earth have changed throughout history
(example – dinosaurs).
b. Rocks – prove that the Earth‟s plates have
moved over time, which impacts the
environments in which organisms live (example
– there are sea shell fossils in the rocks on Mt.
Everest).
c. Ice cores – when scientists drill into polar ice caps,
there is evidence that the climate has changed
throughout Earth‟s history. Climate change impacts
the environment in which organisms live (example –
ocean temperature being raised as a result of global
warming impacts the organisms living in the ocean).
V. Evidence of Evolutionary Descent
a. The fossil record enables the reconstruction of
evolutionary history, scientists study:
i.
Comparative anatomy: the study of anatomical
(physical) features of animals of different species
ii. Homologous body structures: similar
body structures and systems between
different species
iii. Embryological similarities:
similarities in the embryonic stage of
development between different species
On the lined sheet of paper attached to your
notes, add the following information to the
questions you answered at the beginning of the
PowerPoint.
After
What is
evolution?
• What is evolution?
▫ The change of a species over time
• What are mutations?
▫ Mutations occur when there is a
modification to an organism‟s
DNA which cause some kind of
change in an organism.
• What is a common ancestor?
▫ A common ancestor is an
organism from long ago that all
living things came from via
evolution.
VI. Three Way Tie – In the graphic organizer below, write the definition for
the terms in the boxes provided. On the lines connecting the terms,
describe how the terms are related.
Evolution:
A change in the inherited
traits of a species from one
generation to the next
Evolution is a process that describes
how a species changes over time
Species:
A group of organisms that
are able to produce
offspring that are healthy
and capable of reproducing
Extinction is what happens when an
organism does not evolve
Extinction is
when a
species
completely
disappears
Extinction:
When all of the organisms
within a species die (over a
relatively short period of
time)
Draw this diagram on
the lined sheet o paper
attached to your notes.
Evolution does not only
refer to the change of a
species over time, we can
use it to describe any
change over time
Biological
The change of
living organisms
over time
EVOLUTION
A change over time
Geological
The change of the
earth over time
Ex: continental drift,
mountains forming,
erosion, etc.
Technological
The change of
technology over time
Ex. Phones, cell phones,
computers, agricultural,
biotechnology
Whale Evolution