March 10, 2011
Warm
up
Mutagens
Mutation
Changes
in
Genotype
and
Phenotype
De4inition
De4inition
of
mutation:
Bad
Major types of Mutagens
1.
2.
Different
Types
of
Mutations
1.
Good
2.
Neutral
3.
March 10, 2011
Warm
up
Mutagens
Mutation
De4inition
De4inition
of
mutation:
Something
that
causes
a
A
gene,
part
of
a
gene,
part
of
a
chromosome
or
permanent
change
in
base
pair
that
is
changed.
the
DNA.
Major types of Mutagens
1.
Energy:
Radiation,
UV
light
from
the
sun.
*
Chernobyl
*
Nagasaki/Hiroshima
2.
Different
Types
of
Mutations
1.
Base
pairs
or
entire
sections
of
a
chromosome
can
4lip‐
4lop
or
switch
places.
2.
Base
pairs
or
entire
sections
of
a
chromosome
or
a
gene
can
be
deleted.
Changes
in
Genotype
and
Phenotype
Bad
Sickle
Cell
Down's
Syndrome
Scoliosis
Patau's
Syndrome
Good
Sickle
Cell
Super
Toddler
High
metabolism
Being
tall
in
hot
climates
Being
short
in
cold
climates
Neutral
Recessive
alleles
like
blonde
hair,
blue
eyes,
light
skin
etc.
Chemicals
*
cancer
from
Benzene
3.
Base
pairs
or
entire
sections
of
a
gene/
chromosome
can
be
added.
March 10, 2011
Today's Goals:
Looking at Beneficial Mutations in a Population
1. What mutations are beneficial/helpful?
2. How can mutations change a population of
animals or people to change over time?
3. What makes a mutation useful or harmful?
4. Why does a species need mutations in its
population for the species as a WHOLE to
survive?
March 10, 2011
Mutations
‐‐>
New
Phenotypes
‐‐>
Helpful!?
5.
How
is
the
pale
skin
mutation
advantageous
(helpful)
in
cold
areas
but
a
problem
in
warm
climates?
6.
Most
people
who
have
survived
to
pass
on
their
genes,
who
live
in
tropical
regions
have
dark
skin.
How
did
this
help
them
survive
in
order
to
reproduce?
7.
How
is
curly
hair
helpful
in
warm
climates,
while
the
straight
hair
mutation
is
more
advantageous
in
cold
climates?
8.
Why
is
height
also
more
advantageous
in
hot
climates,
while
it
is
a
problem
in
cold
climates?
(In
other
words,
how
did
the
"being
short"
mutation
help
people
in
cold
climates?)
http://tlc.discovery.com/videos/understanding-shorts-race-is-fiction.html
Let's
Illustrate
It!
March 10, 2011
MUTATIONS
in
Individuals
Variety
in
Population
Reproduction
&
Heredity
Population
Changes
over
Time
Key
Example:
Sickle
Cell
Anemia
March 10, 2011
MUTATIONS Accidental
changes
in
the
DNA
Variety
Cause
many
different
types
of
alleles,
diseases,
and
small
changes
in
organisms
Reproduction
&
Heredity
These
small
changes,
because
they
are
in
the
DNA
are
passed
on
IF
the
organism
survives
through
heredity!
If
the
trait
is
bene4icial
or
HELPFUL,
then
more
people
will
live,
and
more
people
will
pass
on
those
"good
genes."
Change
in
Population
over
Time
Sickle
Cell
Anemia
March 10, 2011
Focus Questions
1. What causes malaria?
2. What cells does malaria target?
3. Why is having one sickle cell anemia
allele GOOD while having TWO is a
problem?
4. Why is having NO sickle cell anemia a
problem?
5. Why is variation in a population good?
6. How does that change the population over
time?
7. How does this relate to Europe's black
plague?
March 10, 2011
Mutations
&
Whole
Populations
Case
Study:
Sickle
Cell
Anemia
Let's
watch
how
a
mutation
can
be
helpful
AND
harmful
at
the
same
time!
http://www.pbs.org/wgbh/evolution/library/01/2/quicktime/l_012_02.html
March 10, 2011
How
did
the
population
change?
1.
The
ENVIRONMENT
makes
it
a
good
place
for
the
disease,
malaria
to
thrive,
because
it
lives
in
mosquitos.
2.
Some
random
humans
are
born
with
the
Sickle
Cell
Anemia
mutation/disease.
3.
Mosquitos
bite
all
the
humans
and
exchange
blood.
4.
The
people
with
regular
blood
get
sick,
many
die.
Their
population......
5.
The
people
with
Sickle
Cell
are
in
pain
BUT........
So
their
population....
6.
Over
a
couple
hundred
years,
we
end
up
seeing
more
people
that........................
and
less
people
that
...................
because...........
March 10, 2011
-
Sickle
Cell
Anemia
MUTATIONS
Variety
Reproduction
&
Heredity
Change
in
Population
over
Time
March 10, 2011
-
Sickle
Cell
Anemia
MUTATIONS
A change in the DNA, caused by chemicals
to sunlight. If it's passed on, it can change
your traits. --> Sickle Cell
Variety
When
a
mutation
happens,
it
puts
more
variety
into
the
population.
Because
of
a
mutation,
we
have
regular
shaped
blood,
and
sickle
shaped
blood.
We
have
different
eye
and
hair
colors,
different
blood
types,
and
a
variety
of
different
traits.
Reproduction
&
Heredity
If
the
mutation
results
in
a
trait
that
is
helpful,
the
organism
with
that
mutation
has
a
better
chance
surviving,
having
kids
and
passing
on
that
trait.
Sickle
cell
is
usually
thought
of
as
negative,
but
in
some
places
in
the
world,
its
a
positive
mutation
because
it
helps
people
survive
against
malaria.
Change
in
Population
over
Time
Over
many
generations,
organisms
with
the
helpful
mutation
survive
and
pass
it
on
to
their
offspring.
Sickle
cell
anemia
is
found
more
in
places
with
malaria
because
many
of
the
originally
healthy
people
die,
and
those
who
survive
with
SCA
have
kids
and
pass
on
the
disease!
March 10, 2011
CHALLENGE:
We
know
that
mutations
cause
variation
on
the
planet.
Why
does
ANY
SPECIES
(from
human
to
mouse
to
bird....)
NEED
VARIATION
in
order
for
their
species
to
survive?
(Keep
in
mind‐‐
it
doesn't
really
matter
if
an
INDIVIDUAL
survives‐‐
just
that
the
SPECIES
as
a
whole
does)
Answer:
The
environment
is
always
changing.
If
there's
no
variety,
and
the
environment
changes,
a
whole
species
could
die
off.
March 10, 2011
BONUS
INFORMATION
March 10, 2011
March 10, 2011
March 10, 2011
SO
FAR,
we've
really
only
talked
about
mutations
that
are
BAD.
But
mutations
can
also
be
neutral
or
even
GOOD!
March 10, 2011