2. science
1.A branch of knowledge dealing with a body of facts
or truths systematically arranged.
2.Systematic knowledge of the physical or material
world gained through observation and
experimentation.
3.Knowledge, as of facts or principles; knowledge
gained by systematic study.
4. the unknown past
Scientists who study the past need to use
different methods than those who study things
that are observable.
They are like detective, putting clues together,
trying to paint a picture of what occurred. They
use what they know about the evidence and what
they know about cause-and-effect relationships.
5. How do we test something that occurred
in the past? something that occurs very
slowly?
6. We must use historical science to
determine what happened in the past.
8. historical science
You awake and look outside.
evidence 1:
the driveway is covered in water
and
evidence 2:
the car in the driveway is also wet
9. historical science
What can you conclude?
it rained while you slept
or
the automatic sprinklers came on
10. historical science
But then you see the following:
evidence 3:
the lawn and the street are perfectly dry
and
evidence 4:
there are no clouds in the sky
11. historical science
Now what?
Rain storm and sprinkler
are still possible
but
are less likely because of
evidences 3 and 4
(lawn dry & no clouds)
12. historical science
You look at bit harder
and see
evidence 5:
a bucket with soapy water
and a sponge behind the car
13. historical science
Now with the last piece of
evidence (the soapy bucket),
it is much more obvious:
Someone washed the car.
14. historical science
This is an example of making an
guess about the past using
historical reasoning.
You missed what happened,
because you were asleep, but
there remains some clues.
15. historical science
Using those clues, your
job is to come up with
the best explanation.
You start with the evidence and
with other knowledge you have
about the world.
You work backwards to infer
what probably happened when
you were not there to observe it.
16. historical science
The best explanation will
be the one that explains
most of the evidence.
17. What are the various viewpoints on the
origin of species?
18. creationism
a doctrine or theory
holding that matter, the
various forms of life, and
the world were created
by God out of nothing
and usually in the way
described in Genesis
19. intelligent design
The theory of
intelligent design
holds that certain
features of the
universe and of
living things are best
explained by an
intelligent cause, not
an undirected
process such as
natural selection.
21. evolution
This definition
encompasses
small-scale
evolution,
microevolution -
changes in gene
frequency in a
population from
one generation to
the next and...
23. evolution
Biological evolution is not simply a matter of change over
time. Lots of things change over time: trees lose their
leaves, mountain ranges rise and erode, but they aren't
examples of biological evolution because they don't
involve descent through genetic inheritance.
24. evolution
The central idea of
biological evolution is that
all life on Earth shares a
common ancestor.
Through the process of
descent with
modification, the
common ancestor of life
on Earth gave rise to the
diversity of the various
species.
25. who was the main person to put evolution on the table?
charles darwin What book did Darwin
write explaining his theory
of evolution?
On The Origin of Species
28. darwin’s theory:
evolution through natural selection
Darwin studied 13
species of finches.
They were all similar,
except for their:
body size
beak shape
eating habits
29.
30. darwin’s theory:
evolution through natural selection
Darwin thought the
varieties of plants and
animals could be best
explained by descent from
a common ancestor.
He used the plants and
animals of the Galapagos
Islands as an example.
31. darwin’s theory:
evolution through natural selection
The mechanism Darwin thought that was responsible for
evolution was Natural Selection.
He argued that it had the power to make new forms of
life.
32. natural selection
Darwin’s idea became known as the
Theory of Evolution by Natural Selection.
Natural Selection means that organisms with traits
best suited to their environment are more likely to
survive and reproduce.
Overtime, as new data was gathered and reported,
changes were made to Darwin’s original ideas about
evolution by natural selection.
33. principles of natural selection
1. Organisms produce more offspring than can survive.
2. Differences, or variations, occur among individuals of a
species.
3. Some variations are passed to offspring.
4. Some variations are helpful. Individuals with helpful
variations survive and reproduce better than those
without these variations.
5. Over time, the offspring of individuals with helpful
variations make up more of a population and eventually
may become a separate species.
35. adaptation
Over time, the genetic makeup of a species might
change its appearance.
Many kinds of environmental factors help bring
about changes.
When individuals of the same species move into
or out of an area, they might bring in or remove
genes and variations.
36. variations
A variation is an inherited trait that makes an
individual different from other members of its species.
Variations result from mutations.
Some gene changes produce small variations, such
as differences in the shape of human hairlines.
Other gene changes produce large variations, such
as an albino animal in a population of normal colored
animals.
If individuals with these variations continue to survive
and reproduce over many generations, a new species
can evolve.
37.
38. darwin’s theory has evolved
Darwin did not understand genetics, like you do.
He did not know how traits are passed from one
generation to another.
Once scientists learned more and more about
genetics and mutations, Darwin’s Theory was
modified.
The modern theory is called neo-Darwinism.
39. neo-darwinism
The theory of evolution
based on Darwin’s
original theory of
evolution of species
through the process of
natural selection
together with current
understandings and
theories of genetics and
inheritance.
40.
41.
42.
43.
44. which theory is right?
There still remains much debate over the origin of
species.
Sometimes the evidences can be explained in
more than one way -- this is where different
theories and debates are made.
The claims of the theories cannot be tested, but
by looking at all the evidence carefully, we can
decide which theory seems more logical.
45. which theory is right?
Our goal, grade 8 students, is to examine the
scientific evidences and make our own
educated decisions on the origin of life.
