Transcript Genetic Drift - Cloudfront.net

Semester 2 Table of Contents
Catalyst #6 Pg. 23
5. Lesson 60- Mutations and
Evolution
Pg. 15-18
6. Lesson 62- Genetic Variation
Pg. 19-22
7. Lesson 63- Genetic Drift
Pg. 23-26
Assigned Vocabulary- Due 2/11
13. Genetic Drift
14. Founder’s Effect
15. Bottleneck Effect
Justify your answer in complete
and sentences.
Vocabulary Due TODAY
Announcements
• Evolution Quiz #2- Friday
• Notebook Check #1- Next Monday
– Will count as HW/classwork grade= 16.5%
of final grade
Get Ready for Vocabulary RaceTake out whiteboard marker
• BEHAVIORAL EXPECTATIONS:
– Noise Level 2- Can’t hear you from a few feet away
– Facing forward
– Bottoms in chairs whole time
– Stay in seat
• DIRECTIONS:
– Answer your specific question
– Pass up the whiteboard
– Last person in row hold up whiteboard
– I’ll take 1st 2nd, and 3rd place
– Team that wins will get bragging rights!
Round 1
1. This is a change in a species over time; process of biological
change by which descendents come to differ from their
ancestors.
2. This is a mechanism by which individuals that have
inherited beneficial adaptations produce more offspring on
average than do other individuals
This type of white blood cell phagocytizes small particles
3. This person published On the Origin of the Species by
Means of Natural Selection
4. This is a measure of an organism’s ability to survive and
produce offspring relative to other members of a
population
Round 1
1.
This is a change in a species over time; process of biological
change by which descendents come to differ from their
ancestors.
1.
2.
This is a mechanism by which individuals that have inherited
beneficial adaptations produce more offspring on average than
do other individuals
1.
3.
natural selection
inherited trait that is selected for over time because it allows
organisms to better survive in their environment
1.
4.
Evolution
Charles Darwin
This is a measure of an organism’s ability to survive and produce
offspring relative to other members of a population
1.
fitness
Round 2
1. differences in physical traits of an individual from
the group to which it belongs. You often give this
2. ability of a trait to be passsed from one
generation to the next
3. inherited trait that is selected for over time
because it allows organisms to better survive in
their environment
4. body part that is similar in structure on different
organisms but performs different functions
Round 2
1. differences in physical traits of an individual from the group
to which it belongs.
1.
variation
2. ability of a trait to be passsed from one generation to the
next
1.
inheritability
3. inherited trait that is selected for over time because it
allows organisms to better survive in their environment
1.
adaptation
4. body part that is similar in structure on different organisms
but performs different functions
1.
Homologous structure
Round 3
1. remnants of an organ or structure that
functioned in an earlier ancestor
2. the study of the earliest stages of growth and
development of plants and animals
3. collection of alleles found in all of the
individuals of a population
4. proportion of one allele, compared with all
the alleles from that trait, in the gene pool
Round 3
1. remnants of an organ or structure that functioned in
an earlier ancestor
1. Vestigial structure
2. the study of the earliest stages of growth and
development of plants and animals
1. embryology
3. collection of alleles found in all of the individuals of a
population
1. Gene pool
4. proportion of one allele, compared with all the alleles
from that trait, in the gene pool
1. Allele frequency
Question of the Day Pg. 23
• Use your prior knowledge to answer the
following question on pg. 23
• How does genetic drift affect the diversity of a
population?
Get Ready for Notes Pg. 24-25
Title: Genetic Drift
No HW questions
• Behavior:
– Silent
– Not looking at ipads
– Head up
– Facing forward
Genetic Drift
DNA frequency in a population
changes simply by CHANCE not
fitness

Survivors are lucky, not more fit

Deceased are unlucky, not less fit
Causes of Genetic Drift

Random events:
1. natural disasters – hurricane,
volcano, tsunami, earthquake,
fire, etc
2. stepped on, ran over, picked
up, put on a boat, stuck in a
car, stuck to fur or clothing
3. at the wrong place at the
wrong time
Types of Genetic Drift
1. Founder’s Effect
some individuals of a
population colonize
a new habitat
2. Bottleneck Effect
few survivors are left
to reproduce
FOUNDER'S EFFECT:


some individuals of a population colonize
a new habitat
ex: Columbus bringing organisms to USA
Spain: DNA
Frequency
66% pink
33% red
S. America:
DNA
Frequency
25% pink
75% red
Bottleneck Effect:


few survivors are left to reproduce
ex Hurricane Katrina
survivors!
Before Katrina:
DNA Frequency
66% pink
33% red
After Katrina:
DNA Frequency
40% pink
60% red
How does genetic drift affect the diversity of a
population over time?
Genetic drift decreases diversity. In this case
yellow and pink DNA are gone, and red DNA is
now the majority.
Genetic drift = decrease in DNA diversity
Let's Do This Together:

Did this population of Rivasitus
undergo genetic drift after a tornado
killed all except one X and one O?
Allele frequency of Original
Population:
13/26 X's = 50%
13/26 O's = 50%
X O O X X
XO O OO
X X X X
X X X X XO
OOOOOO
Allele frequency of New
Population:
1/2 X's = 50%
1/2 O's = 50%
XO
survivors!
Let's Do This Together:
Did this population of Rivasitus
undergo genetic drift?
Original Population: New Population:

13/26 X's = 50%
13/26 O's = 50%
X O O X X
XO O OO
X X X X
X X X X XO
OOOOOO
1/2 X's = 50%
1/2 O's = 50%
NO
XO
DNA frequency
the SAME
before and after!
You Try:

Did this population of Rivasitus
undergo genetic drift?
Allele Frequency of Allele Frequency
Original Population: of New Population:
__/__ X's = ___%
__/__ O's =___%
X O O X X
XO O
X X
X XO
OO O
__/__ X's = __%
__/__ O's = __%
XOXX
O
YES!
You Try:
Did this population of Rivasitus
DNA
frequency
undergo genetic drift?
different before and after!
Original Population: New Population:

8/16 X's = 50%
8/16 O's =50%
X O O X X
XO O
X
X
X XO
OOO
3/5 X's = 60%
2/5 O's = 40%
XOXX
O
Check your understanding!
• Watch the video then answer the
questions
• http://glencoe.mcgrawhill.com/sites/9834092339/student_vie
w0/chapter20/simulation_of_genetic_dr
ift.html
• On the top of page 24 write how many
questions you got correct out of 5
Genetic Drift Investigation PG. 26 (10
MIN)
• Quietly work with your partner to
answer the question on in your
notebook
• DO NOT WIRTE ON WORKSHEET
REVIEW OF INVESTIGATION
GENETIC DRIFT WITH DICE: WORM
Coloring (20 MIN) PG. 26
WORM REVIEW (5 MIN)
ANSWER QUESTION OF THE DAY Pg.26
• How does genetic drift affect the
diversity of a population?
• Draw a picture to help explain your
answer
Evolution Video?