Transcript CONPTT power point - Liberty Union High School District

Six Criteria of Science :
Consistent,
Observable,
Natural,
Predictable,
Testable,
Tentative.
Consistency : The results of
observations and/or experiments are
reasonably the same when repeated.
1.
2.
Green plants will grow towards a light source.
Walking under a ladder will cause bad luck.
Observability : The event or evidence
of the event, can be observed and
explained. The observations are limited
to the basic human senses or to
extensions of the senses.
1.
2.
Some plants eat meat.
Extraterrestrial beings have visited Earth.
Natural : A natural cause (mechanism)
must be used to explain why or how
the event happens.
1. Green plants convert sunlight into energy.
2. With a rod, Moses parted the sea so his
people could cross to the other side..
Predictability : Specific predictions
can be used to foretell an event.
Each prediction can be tested to
determine if the prediction is true or
false.
1.
2.
Without sunlight (or artificial light), green plants will
die.
If you are a "Scorpio", your horoscope for today is
"You'll be saying 'I feel rich !' Lunar position
highlights back pay, refunds, correction of
accounting error."
Testability : the event must be
testable through the processes of
science, and controlled
experimentation.
1.
2.
The Bermuda Triangle causes ships and
planes to sink and disappear.
Life comes from life and cannot come from
non-life.
Tentativeness : Scientific theories are
changeable and correctable, even to
the point of the theory being proven
wrong. Scientific theories have been
modified and will continue to be
modified
1.
2.
Pluto was once a planet but due to it’s orbits, is
now considered a dwarf planet.
We know that the world began about 6000
years ago, and nothing will change that.
Evolution= Gradual change over time
Adaptation
Adaptations are inherited traits that
increase a group’s chance of
survival & reproduction
This type of finch has a
thick beak  adaptation
for cracking open seeds
Variation
Within a species, there is variation
Variation = differences between members
of a population
Species = group that can breed & produce
healthy offspring
The Scientists
Jean Baptist Lamarck
vs.
Charles Darwin
Jean Baptiste Lamarck
Evolution occurs as structures
develop through use, or
disappear because of disuse,
and these “acquired
characteristics”
are passed to offspring.
EXAMPLE:
Over a giraffes lifetime it can stretch it’s
neck and it’s offspring will be born with
long necks….
Valid?
Darwin and The Monkey!
THIS IS NOT
WHAT HIS
THEORY
SAYS
Who was Charles Darwin
 Studied
 Hated
medicine
the sight of blood
 Received
a BA in Theology
 Had 10 children
 Darwin was a Naturalist
on the HMS Beagle
Theory of Evolution

In The Galapagos Islands, Darwin
collected species of finches (13)
 Each had a specialized diet and beak
structure
 These finches all closely resembled a
South American finch ancestral
species
 On the trip Darwin saw things he could
only attribute to a process called:
“Natural Selection”
Darwin’s Finches
Theory of Evolution
Hypothesized that the differences were do
to gradual change
 Darwin referred to such change as “descent
with modification” – evolution;
 Wrote Origin of Species
 He still wondered
“How does evolution occur?”

After his voyage, Darwin made the
following inferences:
1.
2.
3.
4.
5.
There is variation within populations
Some variations are favorable
Not all young produced in each
generation can survive
Individuals that survive and reproduce
are those with favorable variations
Favorable traits will increase in future
generations.
Darwin called this process by which
populations change in response to
their environment:
Natural Selection
Evolution happens because
of natural selection
Selection acts on individuals, populations evolve
Change creates advantages
for some species &
disadvantages for others
Fossils reveal changes in species over
millions of years
Evidence for Evolution
1.

Fossils
show change over time


–
scientists can date fossils & use them to
support the theory of evolution
common ancestors reveal whether
species are related
Anatomy of living species also
shows relatedness
How Anatomy supports Evolution
2.
Homologous Structures


Traits similar in different species
because they share a common ancestor
Ex: human arm, dog front limb, horse
leg, whale fin
These “ look the
same.” They have
the same bones
but different
function.
How Anatomy supports Evolution
3. Analogous structures
 Distantly
related species have structures that
have the same function but are different in
structure
 Ex: wing of butterfly & bird
These “ work the
same.” They have
different bones
but the same
function.
How Anatomy supports Evolution
4. Vestigial structures



Structures reduced in size & often
unused
Remains of functional structures
inherited from an ancestor
Ex: leg & hip bones in pythons & whales
How DNA Supports evolution
5. Molecular Evidence
 Also called biochemical evidence
 Compares biomolecules such as DNA or
amino acid sequences between organisms
 Related organisms have more of the same
molecules in common
So….. Where Do
New Species
Come From?
How do new species form?
1.
Geographic Isolation


When members of a population are
separated
Ex: polar, grizzly, & black bears
2. Reproductive Isolation
 When
members of a population can’t
breed even though they live nearby
 Ex: different mating seasons or different
mating calls
Different Types of Evolution
1.
2.
3.
4.
Divergent evolution
Convergent evolution
Coevolution
Adaptive radiation
Divergent Evolution
-Isolated populations evolve
independently
Ex: polar & grizzly bears
changed independently due to
different habitats
Convergent Evolution
-Unrelated species become more
alike because they live in similar
environments
Ex: shark & dolphin
Coevolution
-Species that interact closely adapt to one
another
Ex: Flowers & Pollinators
(Birds, Bees and Butterflies too)
Adaptive Radiation
Evolution of many diverse species from
one common ancestor
Ex: famous Galapagos finches discovered
by Darwin
Questions?