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How do individuals and groups with
different genes arise?
Evolution…
Does it occur?
How does it
occur?
CB 5.25
Information
flow in cells
Protein
The relationship between DNA and genes
a gene - DNA used to produce RNA or protein
promoter
coding region
terminator
non-gene
DNA
CB 5.25
Genes are the
parts of DNA
that contain
information.
Protein
CB 17.4
Combinations of
3 nucleotides
code for each 1
amino acid in a
protein.
For life to exist,
the information
(genes) must be
passed on.
1. Genes act as units of
heredity
5. Genes are replicators
(selfish gene)
CB 13.5
CB 13.5
As organisms
reproduce the DNA
is passed on to the
next generations.
Mitosis
Chains of DNA can store information:
Complementary base pairs suggest how
DNA replication occurs
When DNA is replicated,
mutations can occur.
CB 13.5
DNA must be
replicated before it
can be passed on.
How it is passed on
and how it gets
modified impacts
evolution.
Mutations: Sickle-cell anemia
CB 17.23
CB 5.21
Differences in
amino acid
sequence lead to
differences in 3-D
shape and different
functionalities
Correlation of malaria
and sickle-cell anemia
CB 23.10
How do individuals and groups with
different genes arise?
Evolution…
Does it occur?
How does it
occur?
Does evolution occur?
As DNA changes;
traits change.
Protein
Evolution: A species’ genetic component
changes as the individuals reproduce.
Evolution: A
species’ genetic
component
changes as the
individuals
reproduce.
These changes
are based on
how the DNA
changes and
who
reproduces.
Evolution: changes in DNA as information transmitted
O
O
O
O
O
O
O
O
Bacteria with mutation
causing resistance
O
O
O
Evolution: changes in DNA as information transmitted
O
O
O
O
O
O
O
O
Bacteria with mutation
causing resistance
O
O
O
Apply
antibiotic
X
O
O
O
X
X
O
X
X
X
O
O
X
X
O
X
X
O
O
O
O
Kills most bacteria.
Except if some have mutation
that allow them to be resistant.
Evolution: changes in DNA as information transmitted
O
O
O
O
O
O
O
O
Bacteria with mutation
causing resistance
O
O
O
Apply
antibiotic
O
X
O
O
O
X
X
O
X
X
X
O
O
X
X
O
X
X
O
O
O
O
Kills most bacteria.
Except if some have mutation
that allow them to be resistant.
Continues to
replicate
Evolution: changes in DNA as information transmitted
O
O
O
O
O
O
O
O
Bacteria with mutation
causing resistance
O
O
O
Apply
antibiotic
Continues to
replicate
O
X
O
O
X
O
O
O
O
Kills most bacteria.
Except if some have mutation
that allow them to be resistant.
X
O
O
X
X
O
X
X
X
O
O
X
X
O
O
O
O
O
O
O
O
O
O
O
Population of resistant bacteria
Reproductive success = evolutionary success
Natural Selection:
Individuals that are most
successful at reproducing will
pass on more of their genetic
information.
Individuals are selected…
But populations evolve via changes in DNA
during reproduction.
Who evolves?…Species.
A. harrisi
A. leucurus
•A population that can produce fertile offspring
•A population that does reproduce
**A population sharing genetic information**
CB 24.6
X
Horse
Donkey
=
Mule
X
Horse
=
Mule
(sterile)
Donkey
So…horses and
donkeys are not
the same species.
Who evolves?…Species.
A. harrisi
A. leucurus
•A population that can produce fertile offspring
•A population that does reproduce
**A population sharing genetic information**
CB 24.6
Reproductive success = Evolutionary success
Reproductive success = Evolutionary success
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Evolution:
A species’ genetic component changes as the
individuals reproduce
For natural selection to
take place the following
conditions must be met…
• Not all individuals can reproduce
• Genetic diversity gives rise to
individuals with different traits
Genetic diversity is needed for natural selection
to occur.
CB 23.12
Reproduction/
Selection
Artificial Selection
from Teosinte
Maize
By artificial selection that
began ~10,000 years ago.
Different foods
from one
species of plant.
Created by
artificial
selection.
CB 22.10
Wild member of Brassica oleracea:
small side buds
Artificial selection
Number of Individuals
1. Select individuals
that have the largest
side buds and breed
them.
2. Of the offspring,
select individuals that
have the largest side
buds and breed them.
3. Of the offspring,
select individuals that
have the largest side
buds and breed them.
4. After several
generations, bud size
increases dramatically.
0
Brussels sprouts:
extremely large side buds
1
2
Size of buds (cm)
3
DNA is
passed from
generation to
generation,
and therefore
can tell us
about
relationships
between
species.
How are we related to our ancestors, and
where did we come from?
How old am I?
CB 34.43
1.7 million-year-old
human ancestor
CB 34.43
More than 10,000
years ago:
Hunter-Gatherer
~10,000 to 200
years ago:
Farming-Ranching
Last 200 years: Industrialization
Agricultural
HunterGatherer
Industrial
The earth is covered in humans. How did this
occur?