Transcript Genetic Frequency and natural selection One

Gene Frequency and
Natural Selection
Presented by your lovely team: That One Class
May 2014
A summary of Natural selection and
Gene frequency
•
Natural selection: the process when individuals with certain genotypes are more likely than
individuals with other genotypes to survive and reproduce, and thus to pass on their alleles to
the next generation. As Charles Darwin (1859) argued in On the Origin of Species, if the
following conditions are met, natural selection must occur:
•
•
1) There is variation among individuals within a population in some trait.
2) This variation is heritable (i.e., there is a genetic basis to the variation, such that offspring
tend to resemble their parents in this trait).
3) Variation in this trait is associated with variation in fitness (the average net reproduction of
individuals with a given genotype relative to that of individuals with other genotypes).
•
Kim
•
Gene Frequency: the variant of a gene percentage of all alleles at a given locus in a population
gene pool.
•
In other words, It is the number of copies of a particular allele divided by the number of copies
of all alleles at the genetic place (locus) in a population. It is usually expressed as a percentage.
In population genetics, allele frequencies are used to depict the amount of genetic diversity at
the individual, population, and species level. It is also the relative proportion of all alleles of
An example of Natural
Selection
Imagine a population of beetles:
1. There is variation in traits.
In this case, there are two types of
beetles: green and brown.
2. There is differential reproduction.
There is a predator (in this case, it’s a
bird) that limits the population by
feeding off of the green beetles that
stick out more in a desert
environment.
3. There is heredity.
The surviving brown beetles can
continue to reproduce.
4. End result: In this particular
environment, brown beetles are more
advantageous and are more suited for
that environment.
Kim
An example of Gene
Frequency
•Allele frequencies show the genetic
diversity of a species population or like
the richness of its gene pool.
•Alleles of the parent are shuffled and
passed down to their offspring
•Dominant alleles get passed on to the
next generation or offspring and tends
to reveal the physical characteristics of
an individual
•Recessive alleles do get passed, but
tend to not reveal the physical
characteristics within an individual.
Kim
Materials Used during Natural
Selection and Gene Frequency
Natural Selection
Materials
 40 Pink Pop Dots
 40 Teal Pop Dots
 40 Green Pop Dots
 40 Orange Pop Dots
Team
Dominant: 50 beads Recessive: 50 beads Mutation: 20 beads
Team 1
Orange
White
Green
Team 2
Red
Green
Blue
Team 3
Blue
Yellow
White
 40 Blue Pop Dots
 40 Red Pop Dots
 40 White Pop Dots
 40 Brown Pop Dots
 40 Black Pop Dots
 Pink and Green Stripes Environment
* 6 to mix to pair and an extra 1 cup for the dead beads
 Pink Cell Phones Environment
Devan
Manaz Mohamed
Methods of explaining the
relationships between Gene
Frequency and Natural selection
Natural selection
Generations
Predators
Claws
Time
Environment
Gen 1
1
1
1 min
Pink and green
stripes
Gen 2
1
2
1 min
Pink and green
stripes
Gen 3
1
1
1:30
Pink and green
stripes
Gen 4
1
2
2 min
Pink cell
phones
Gen 5
2
3
1 min
Pink cell
phones
Gen 6
2
4
1:30
Pink cell
phones
Devan
Heterozygous forecast for
12 generations between 2
teams
Data provided by
Ruben
6 Generation Forecast for Heterozygous Genotype in 4 Select
Cases of Selective Pressure. TEAM 2
6 Generation Forecast for Heterozygous Genotype in 4 Select
Cases of Selective Pressure
60%
60%
50%
50%
50%
44.4% 45.5%
40%
% of Population
50%
50%
41.9%
38.1% 39.0%
34.0%
30%
28.0%
24.5%
30%
20%
Bb -33%
20%
Bb -100%
By 100% + Mutation
10%
Linear (Bb Base)
Linear (Bb -33%)
% of Population
Bb Base
24.0%
25.8%
16.4%
Rr Base
17.7%
Rr -10%
10%
13.8%
Rr -100%
6.6%
Rr 100% + Mutation
7.4%
0%
1
2
3
4
5
0.0%
6
0.0%
7
-10%
Linear (By 100% + Mutation)
1
2
3
4
5
6
50%
50%
50%
50%
50%
50%
Bb -33%
50.0% 50.0% 53.3% 46.2% 43.2% 50.0%
Bb -100%
50.0% 47.4% 47.1% 36.4% 32.3% 33.3%
7
8
9
10
11
12
9
10
11
12
Linear (Rr Base)
Linear (Rr -10%)
Linear (Rr 100% + Mutation)
-20%
-30%
-40%
By 100% + Mutation 38.0% 19.0% 9.0% 17.8% 16.7% 18.0%
Generation
8
Linear (Rr -100%)
Linear (Bb -100%)
0%
-10%
50%
50.0%
40%
Bb Base
50%
50%
-50%
Generation
10% suppression data
Super Adaptive Homozygous Mutation
With 10% Negative Recessive Suppression
0.7
0.6
Percentage of Population
RR
0.5
RB Dominate/Mutation
0.4
BB - SA Mutation
0.3
Homo Dominate/No
Mutation
0.2
Dominant/Mutation
Trend
SA Mutation Trend
0.1
0
Gen 1
Gen 2
Gen 3
Gen 4
Gen 5
Gen 6
Gen 7
Gen 8
Gen 9
Gen 10 Gen 11 Gen 12
Tearm ARS
* Data from Stephanie
Gen 1
RR
Rr
rr-10% Neg. Sel. + Mutat.
RB - Dominate/Mutation
rB - Recessive/Mutation
BB - SA Mutation
Total
16%
34%
14%
14%
18%
4%
100%
Gen 2
18%
28%
10%
16%
24%
4%
100%
Gen 3
17%
25%
15%
17%
17%
9%
100%
Gen 4
16%
16%
11%
20%
24%
13%
100%
Gen 5
13%
18%
10%
21%
15%
24%
100%
Gen 6
9%
7%
5%
28%
21%
30%
100%
Negative 33% suppression
Super Adaptive Homozygous Mutation
With 33% Negative Recessive Suppression
0.5
0.45
Percentage of Population
0.4
0.35
OO 100% + Mutation
OG 100% + Mutation
0.3
GG 100% + Mutation
0.25
Homo Dominate/No Mutation
0.2
Dominant/Mutation Trent
SA Mutation Trend
0.15
0.1
0.05
0
Data by
Stephanie
Gen 1 Gen 2 Gen 3 Gen 4 Gen 5 Gen 6 Gen7 Gen 8 Gen 9 Gen 10Gen 11 Gen12
Team Thug Livin
Gen 1
OO 100%
Ow 100%
ww -33%
OG 100%
wG 100%
GG 100%
+
+
+
+
+
+
Gen 2
Gen 3
Gen 4
Gen 5
Gen 6
Mutation
Mutation
Mutation
Mutation
Mutation
Mutation
15.6%
46.7%
17.8%
11.1%
6.7%
2.2%
23.3%
32.6%
16.3%
14.0%
14.0%
0.0%
31.7%
24.4%
19.5%
9.8%
9.8%
4.9%
27.5%
30.0%
10.0%
15.0%
10.0%
7.5%
23.8%
26.2%
4.8%
21.4%
16.7%
7.1%
18.2%
27.3%
0.0%
27.3%
18.2%
9.1%
Total
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
0% suppression
*Data provided by Stephanie and Kaj
60%
Super Adaptive Homozygous Mutation
Base Case Gene Frequency
With 0% Negative Recessive Suppression
0.8
50%
0.7
0.6
Percentage of Poplution
0.5
BW 100% + Mutation
WW 100% + Mutation
0.4
Homo Dominant Trend
0.3
Dominant/Mutation
SA Mutation Trend
0.2
Percent of Population
40%
BB 100% + Mutation
30%
20%
0.1
10%
0
Gen 1
Gen 2
Gen 3
Gen 4
-0.1
Gen 5
Gen 6
Gen 7
Gen 8
Gen 9 Gen 10 Gen 11 Gen 12
Team One Team
0%
Gen 1
Gen 1
BB
By
yy
BW
yw
WW
100%
100%
100%
100%
100%
100%
+
+
+
+
+
+
Gen 2
Gen 3
Gen 2
Gen 4
Gen 3
RR Base
Gen 4
Rr Base
Gen 5
rr Base
Gen 5
Gen 6
Mutation
Mutation
Mutation
Mutation
Mutation
Mutation
18.0%
38.0%
14.0%
6.0%
14.0%
10.0%
13.8%
19.0%
6.9%
27.6%
22.4%
10.3%
14.6%
9.0%
10.1%
28.1%
12.4%
25.8%
9.6%
17.8%
11.0%
12.3%
15.1%
34.2%
8.3%
16.7%
9.7%
13.9%
13.9%
37.5%
9.8%
18.0%
11.5%
18.0%
18.0%
24.6%
Total
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
Gen 6
Pumpkins data Trend positive effect on
natural selection
•
Data provided by Erica
60
Pumpkin Survivability
Pumpkin Survivability
25
50
40
20
Number 30
of
Survivors
Number
15
of
Survivors
Orange
Pumpkin
Linear (Orange)
20
10
10
5
0
G1
Created
by
Erica
G2
G3
G4
G5
G6
Generation Number
G7
G8
G9
G10
G11
G12
0
Created
by
Erica
1
2
3
Generation Number
4
5
6
• Trend line of negative effects on natural selection
Species Population X Generation
40
35
lt blue species
decrease
30
25
Lt Blue
Population
Purple
Dark Blue
*Natural disaster
took place
20
Orange
Yellow
15
Lt Green
Black
Bright Pink
10
5
0
G1
G2
G3
G4
Generation
G5
G6
Lissette
Sandoval
Mutation Correlation
Postive Mutation without forecast
Postive generation mutatation with forecast
100
50
90
45
80
40
Case RR is More Adaptive /
Competiitve 100% Death
to yellow
Blue Blue BB
Blue Yellow By
35
60
Blue Blue
Blue Yellow
50
Yellow Yellow
Blue White
40
Yellow White
Bead Count
Bead Count
70
Yellow Yellow yy
30
Blue White Bw
Yellow White yw
25
White White WW
20
White White
30
Total
Linear (Case RR is More
Adaptive / Competiitve
100% Death to yellow)
Linear (Blue Blue BB)
15
20
10
Linear (Blue Yellow By)
5
Linear (Blue White Bw)
10
0
100% Death to
yellow
Gen 1
Gen 2
Gen 3
Generations
Gen 4 Forge
Gen 5
Gen 6
Edgar
M
Linear (Blue White Bw)
0
1
2
3
4
5
6
7
Generations
8
9
10
11
12
Edgar M
Conclusion
 Natural selection is a process of to survive within the its environment.
 Gene Frequency is a process of genes passed down through generations
through dominant and recessive genes from parent generations.
 Gene frequency tends to shift towards the phenotypic version that is
best suited for the current environment, while natural
selection weeds out the unfit individuals and allow fit individuals to
breed more increasing the number of "good" alleles.
 Gene Frequency & Natural Selection comparison charts show how a
species can die off by being the less adaptable gene and being more
prone to attack
 Our charts also demonstrate how a species can evolve to become more
adaptable to its environment and show its adaptation cause it to higher
rates of survival.