“Mutation: it is the key to our evolution. It
has enabled us to evolve from a singlecelled organism into the dominant
species on the planet. This process is
slow, and normally taking thousands and
thousands of years. But every few
hundred millennia, evolution leaps
forward.”
- Professor Charles Xavier
 Gene
Mutation: a change in the
specific order of the A, G, C, and T
bases in a particular gene
 “Spirit”
Bears (Kermode Bears)
› White due to a mutation in the gene
for fur colour
› Affects 1 of 10 black kermode bears
3
types of mutations:
› Deletion (one base is missing)
› Addition (one base is added)
› Substitution (one base is substituted
with another
 Mutations
can be positive (beneficial),
negative (harmful), or neutral

A mutation that benefits an individual
EXAMPLE: HIV is a virus that results in AIDS.
 Some people have a mutated gene that
codes for proteins that prevent HIV
infection
EXAMPLE: Plants that have developed
resistance to bacteria/fungi
Small changes in DNA base sequences
that cause harm to the individual
 Reduces the likelihood of reproduction or
survival

EXAMPLE: Sickle Cell Anemia
 Substitution of base A for base T in 1 place
results in misshapen hemoglobin (red
blood cells)
 Result:
› can’t carry oxygen
› blocks blood flow, causing pain and
organ damage
EXAMPLE: Cystic Fibrosis
 can be caused by 1300+ mutations in 1
gene
 Protein is incorrectly made, causing a
mucus buildup
 Chloride levels build, resulting in respiratory
problems

The substitution of 1 base for another
that does not affect the individual
› Same protein will be made without error
EXAMPLE: The Spirit Bear
 The mutated fur colour does not impact
the bear
Substances or factors that can cause
mutations in DNA
 Viruses can cause DNA to be misread or
copied incorrectly

› When DNA is damaged the proteins will not
be made correctly

Cigarette smoke, x ray radiation, UV rays,
pollutants (mercury), and household
chemicals