1 evolution, part ii bio 2215 oklahoma city community college dennis anderson
TRANSCRIPT
![Page 1: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/1.jpg)
1
Evolution, Part II
BIO 2215
Oklahoma City Community College
Dennis Anderson
![Page 2: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/2.jpg)
2
Major Elements Of Life
• Carbon• Hydrogen• Oxygen• Nitrogen
C
OH
N
![Page 3: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/3.jpg)
3
Chemical Evolution
• Carbohydrates• Fatty Acids• Amino Acids
Simple Molecules
OCO
H O H
HNH
H
HCH
H
H
More Complex Molecules
H H
![Page 4: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/4.jpg)
4
Carbohydrates
![Page 5: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/5.jpg)
5
Fatty Acids
![Page 6: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/6.jpg)
6
Amino Acids
![Page 7: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/7.jpg)
7
Figure 02.12
![Page 8: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/8.jpg)
8
Proteinoid Microspheres• Similar to protocells• Protocells
– Reproduce– Natural selection
favored those with the most efficient replicating systems
• RNA• DNA
![Page 9: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/9.jpg)
9
Cyanobacteria
• Photosynthesis– Produce oxygen– Produce
carbohydrates
Carbon Dioxide + Water = Glucose + Oxygen
![Page 10: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/10.jpg)
10
![Page 11: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/11.jpg)
11
Microevolution
• Change in allele frequency of a population– Populations evolve, individuals do not
![Page 12: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/12.jpg)
12
Terms
• Allele– Member of a paired gene
• Dominant allele– Allele that is expressed when combined with a recessive allele
• Recessive allele– Allele that is NOT expressed when combined with a dominant
allele
• Homozygous– Both alleles the same, AA or aa
• Heterozygous– Alleles are different, Aa
![Page 13: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/13.jpg)
13
Terms
• Codominance– Both alleles are dominant, AB blood type
• Gene Pool– All the alleles in a population
![Page 14: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/14.jpg)
14
Math Explains Allele Frequencies
• p + q = 1
• p = percent of dominant alleles in a population
• q = percent of recessive alleles in a population
• If 70% of alleles in a population are dominant then 30% must be recessive
![Page 15: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/15.jpg)
15
Genotype Frequencies
• Square the equation p + q = 1
• p2 + 2pq + q2 = 1
• Correlation between genotypes and variables in the equation are:
• p2 = AA
• 2pq = Aa
• q2 = aa
![Page 16: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/16.jpg)
16
Hardy-Weinberg Equations
• p + q = 1– Frequency of dominant alleles plus frequency
of recessive alleles is 100% ( or 1)
• p2 + 2pq + q2 = 1– AA plus 2Aa plus aa add up to 100% (or 1)
• Applies to populations that are not changing– They are in equilibrium
![Page 17: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/17.jpg)
17
Hardy-Weinberg Example
• Normal pigmentation (not albino) = A• Albinism recessive = a• AA = (p2) = normal• Aa = (2pq) = normal• aa = (q2) = Albinism• 1 in 20,000 people have albinism• aa = 1/20,000 = 0.00005• a = 1/141 = 0.00707
![Page 18: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/18.jpg)
18
First Equation
• p + q = 1– p is the frequency of the dominant allele, A– q is the frequency of the recessive allele a
• p + 0.00707 = 1
• p = 1- q = .9929
![Page 19: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/19.jpg)
19
Second Equation
• p2 + 2pq + q2 = 1
• p2 = AA– .9929 x .9929 = .9858
• 2pq = Aa– 2 x .9929 x 0.00707 = .0140
• q2 = aa– .00005
• .9858 + .0140 + .00005 = 0.99985 or 1
![Page 20: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/20.jpg)
20
Cystic Fibrosis
• Cystic fibrosis affects 1 in 2000 white Americans
• Cystic fibrosis is recessive = cc
• 1 in 2000 = 1/2000 = .0005
• q2 = .0005
• What is q?
![Page 21: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/21.jpg)
21
Value of q
• q is the square root of q2
• q2 = .0005
• Square root of .0005 = .022
• What is p?
![Page 22: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/22.jpg)
22
Value of p
• p + q = 1
• Since q = .022
• Then p = .978 (1-.022)
• What are the values for p2 and 2pq?
![Page 23: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/23.jpg)
23
Values for p2 and 2pq
• P2 = pxp =.978 x .978 = .956
• 2pq = 2 x .978 x . 22 = .043
• 4.3% of population are carriers for cystic fibrosis
![Page 24: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/24.jpg)
24
Problem
• Jack and Jill are expecting a baby. What is the chance the baby will have cystic fibrosis?
![Page 25: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/25.jpg)
25
Solution
• The chance of Jack being a carrier is .043
• The chance of Jill being a carrier is .043
• The chance of two carriers producing a child with a recessive trait is .25
• .043 x .043 x .25 = .0046 @ 1/2000
![Page 26: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/26.jpg)
26
Practical Application of Hardy-Weinberg Equations
• If you know the frequency of the recessive phenotype (aa) you can calculate the percent of the population that are carriers (Aa) and that are AA.
![Page 27: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/27.jpg)
27
Populations are rarely in Hardy-Weinberg equilibrium
• Most populations are evolving
• Factors that cause allele frequencies to change– Nonrandom mating– Genetic drift– Gene flow– Mutation– Natural selection
![Page 28: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/28.jpg)
28
Nonrandom Mating
• Most people choose their mates based on– Physical appearance– Ethnic background– Intelligence– Shared interests
• One-third of marriages are between people born less than 10 miles apart
![Page 29: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/29.jpg)
29
Religious & Cultural Influences
• Many people will only marry within their own religion or culture
• Consanguineous marriages increase risk of birth defects by 2.5 times
![Page 30: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/30.jpg)
30
Hopi Indians
• Albinos stay in village with woman– Cannot tolerate the sun
• Albinos have more opportunity to mate with females
• 1/200 Hopi Indians are albino
• 1/8 are carriers
![Page 31: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/31.jpg)
31
Genetic Drift
• Change in gene frequency when small a group of individuals leave or are separated from a larger population– Founder Effect– Bottleneck
![Page 32: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/32.jpg)
32
Founder Effect
• 10 people leave to found a new population• 1 of the founders has allele A• 10% of new population will have allele A
Original Population
1% has allele AFounders
New Population
10% with A allele
10
![Page 33: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/33.jpg)
33
Ellis-van Creveld Syndrome
• Dwarfism• Extra fingers• Heart defects• High frequency in Amish
population of Pennsylvania• A founder of the population
had allele for the syndrome
![Page 34: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/34.jpg)
34
Bottleneck
• Population almost dies out
• Survivors genes are at a higher frequency in the descendants than the original population
![Page 35: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/35.jpg)
35
Cheetah Bottleneck
• 2 major bottlenecks– 10,000 years ago– 1800’s
• Present cheetah are more alike genetically than inbred lab mice
![Page 36: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/36.jpg)
36
Gene Flow
• When genes move from one population to another• Genes flow between the two populations below
OKC Dallas
![Page 37: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/37.jpg)
37
Gene Flow
• Can change the frequency of genes in a population
• If gene flow stops for a long period of time the two populations may change enough from each other to become new species.
![Page 38: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/38.jpg)
38
No Gene Flow
![Page 39: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/39.jpg)
39
Mutations
• Introduces new alleles into a population
• Most mutations are lethal– Mutation for no heart would be lethal
• Some mutations are beneficial– Block infection of HIV
![Page 40: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/40.jpg)
40
Beneficial Mutation
• Mutation for albinism beneficial for bears who live on the ice and snow
• Polar bears were once part of a population of brown & black bears
• Now polar bears are a separate species
![Page 41: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/41.jpg)
41
Natural Selection
• Some individuals are more likely to survive and pass on their genes than others
• Nature selects against gene for black fur in the arctic – Black fur does not enable bears in that environment to
survive as well
• Nature selects against gene for white fur in Oklahoma– White fur is not as advantageous in Oklahoma
![Page 42: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/42.jpg)
42
Tuberculosis
• Number 1 killer in 1900• Antibiotics decreased cases dramatically• 1980 very few cases• Bacterium that causes TB is constantly
mutating• Mutant strains resistant to antibiotics are
naturally selected to survive
![Page 43: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/43.jpg)
43
Evolution of Tuberculosis
1900 20001980
Cases of TB
![Page 44: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/44.jpg)
44
Sickle Cell Anemia Frequency
• Sickle cell anemia is most common in parts of Africa with malaria
• Carriers who live in an environment with malaria have an advantage– Immune to malaria
![Page 45: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/45.jpg)
45
Why is the frequency of sickle cell anemia lower in the USA population of Blacks than
African populations from which they originated?
• There is no selective advantage for the s allele in an environment with no malaria
• The frequency of the s allele in the USA Black population has dropped significantly in the last 300 years.
![Page 46: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/46.jpg)
46
Stabilizing Selection
• Average value selected for
• Extreme values selected against
![Page 47: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/47.jpg)
47
Directional Selection
• Favors values above or below average
• Population will shift to the favored value
![Page 48: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/48.jpg)
48
Disruptive Selection
• Extreme traits are both favored
• Birds with small bills and large bills are better feeders– In a specific
enrironment
![Page 49: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/49.jpg)
49
Macroevolution
• Evolution that results in new species
![Page 50: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/50.jpg)
50
Allopatric Speciation
• A barrier separates a population into two subpopulations• There is no gene flow between the two populations• Each population changes with time• Changes result in new species.
![Page 51: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/51.jpg)
51
Sympatric Speciation
• Different individuals occupy different parts of the environment
• They breed in the areas they occupy
![Page 52: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/52.jpg)
52
Convergent Evolution
• Whales are mammals• Evolved a fish like body
![Page 53: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/53.jpg)
53
Divergent Evolution
Reptile
Mammal
Bird
![Page 54: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/54.jpg)
54
Coevolution
![Page 55: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/55.jpg)
55
Parallel Evolution
![Page 56: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/56.jpg)
56
Gradualism or Punctuated Equilibrium
![Page 57: 1 Evolution, Part II BIO 2215 Oklahoma City Community College Dennis Anderson](https://reader036.vdocuments.net/reader036/viewer/2022062423/5697c02c1a28abf838cd8ef0/html5/thumbnails/57.jpg)
57
The End