Download Mutation, Evolution, and Natural Selection

Weekly Schedule- Oct. 11-15
DAY 1 Lesson 21. Identity- DNA

Adaptation, Natural Selection, Evolution
DAY 2
Lesson 22. Identity- DNA
 Performance Task- Lab
DAY 3
Lesson 23. Identity- DNA

Lab (2) Organization of Results
Get a laptop (for note taking)
Genes(
DNA)
New copy
(RNA) is
read and
translated
Make copies
of itself
Crossover
(mixing of
code)
www.squidoo.com/geneticsresearch
A trait is
expressed
VC: What is phenotype
Amino acids
(protein) are
formed
DNA
Cracking the
Code
VC: Cracking the code
copied and read
RNA
translated
http://entomology.wisc.edu/~goodman/wgr...rch.html
PROTEIN
While the copying of DNA is
a very accurate process,
what happens when a letter
is altered?
VC: DNA Mutation
GENETIC VARIATION
leads to
Adaptation
Mutation, Evolution, and Natural Selection
DNA is found in the nucleus of the cell
 Http://www.youtube.com/watch?v=ZK6YP1Smbxk
Mutation
 A mutation is a change in gene sequence.
 There are many different types of mutations and causes for
them.
 Some mutations are harmful, while others can be beneficial.
Harmful
Beneficial
How does mutations work?
 DNA is very accurate when making copies of itself,
however, sometimes it makes a mistake.




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Here’s a DNA sequence
AGCCCTTATAGGCTC
What are the corresponding base pairs?
TCGGGAATATCCGAG
Now when it’s being copied it replaces the T with a U.
Rewrite the your answer with U’s instead of T’s.
 UCGGGAAUAUCCGAG
 What amino acids will this be coded for?
 Serine, Glycine, Isoleucine, Serine, Glutamic Acid
The Mutation
 Here’s our original DNA sequence
 AGCCCTTATAGGCTC
 ATCCCTTATAGGCTC





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we replaced the G with a T
Now what are the corresponding base pairs?
TAGGGAATATCCGAG
Now when it’s being copied it replaces the T with a U.
Rewrite the your answer with U’s instead of T’s.
UAGGGAAUAUCCGAG
What amino acids will this be coded for?
Stop, Glycine, Isoleucine, Serine, Glutamic Acid
You can see how replacing 1 base will change everything!
Who was Charles Darwin?
•British scientist that in 1859 published The Origin of Species
•Stated that all life come from a common ancestor, called
evolution
•This happens by a process called natural selection.
• http://www.youtube.com/watch?v=nMgLF8n4DnA
Voyage of H.M.S.
Beagle, 1831 - 1836
90 feet of ship, 74 people living
together for 5 years...
Darwin
Galapagos
Evolution
 Evolution is the change in the inherited traits (passed
on from parents to offspring) of a population over
many generations. These traits could be physical,
chemical or behavioral.
 This change is caused by mutations in the genes.
 http://www.youtube.com/watch?v=yVqJ_mQazik
Adaptation
 Adaptation is the evolutionary process where a
population becomes better suited to its habitat.
 This process takes place over many generations.
 The term adaptation may also refer to a feature which
is especially important for an organism's survival. For
example, the adaptation of horses' teeth to the
grinding of grass, or their ability to run fast and escape
predators.
 Such adaptations are produced in a variable
population by the better suited forms reproducing
more successfully, which is natural selection.
How does Evolution Work?
 Natural Selection- survival of the fittest.
 Natural selection is simply the logical result of four features
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of living systems:
variation - individuals in a population vary from one
another (different genes caused by mutations)
inheritance - parents pass on their traits to their offspring
genetically
selection - some variants reproduce more than others
time - successful variations accumulate over many
generations
There are 2 variations of the beetles, green
and red.
The birds prefer eating the green
beetles.
Over generations the red beetles increase in
population because they are not eaten by the
birds.
More survive to produce more offspring.
Generations later….
Over time the red beetles have been selected over
the green beetles
Why does this not work?
Change through use and disuse
Natural Selection’s Explanation
Ancestors had different
neck lengths
Through natural
selection, longer necks
survived and passed on
their genes.
Eventually all giraffes
had long necks.
ONE Ancestor Many Varieties
• What are the different
types?
•What could cause all
the variety?
http://www.youtube.com/watch?v=sCEeefdaRcw