EEOB 3310 Exam #3
Study online at https://quizlet.com/_hp2cbx
1. Genomes of A Population: In the genomes of a population of any organism, we known that there are
many "genes" containing considerable levels of variation.
2. Assume we have collected genetic data on the frequency of a trait in a random
sample of the population that we are studying.: What information can we expect to have for
the trait?
-Assume the trait has Mendelian inheritance.
-Assume we can obtain accurate phenotype frequencies.
--Let's initially assume co-dominant inheritance (like piebald spotting in the hair of cats).
-We can start with the phenotype frequencies and then calculate observed genotype and allele frequencies.
3. Piebald Spotting in Cats: Co-dominantly inherited trait.
Two alleles.
-S=white
-s=non-white
Three genotypes.
-SS=>50% white
-Ss=5-49% white
-ss-solid non-white
4. The Null Hypothesis Model for Population Genetics/The Hardy-Weinberg
Model: We need to be able to make some predictions about populations. To do this logically, we need to start from
a null hypothesis.
5. What Is The Hardy-Weinberg Model?
How Did We Get This Model?: Let's put our discussion into the context of science in the first decade of
the 20th Century.
Mendelism has been rediscovered.
Biometricians are feuding with Medelians.
How important are discrete "Mendelian" traits compared to "continuous" Darwinian traits?
Those who believed that Mendelian traits are really important presented their evidence.
One scientist in particular: Reginald Punnett.
, EEOB 3310 Exam #3
Study online at https://quizlet.com/_hp2cbx
6. "Mendelism in Relation to Disease": A presentation by R. Punnett to the Royal Academy of Medicine
(February 28, 1908).
Emphasized the existence of simple Mendelian traits in humans.
-Some of Punnett's examples: Eye color, Brachydactyly.
7. Not So Fast: British statistician, in the audience for Punnett's talk--a "biometrician".
Objected to Punnett's interpretation because of the frequency of traits in the population.
Udny Yule (commenting on Punnett's paper): "Assuming that brown or duplex eye-colour was dominant over blue, if
mating of persons of different eye-colours were random (and that was very nearly true), it was to be expected that in
the population there would be three persons with brown eyes to one with blue; but that was not so. There were more
blues than browns."
"The same applied to the examples of brachydactyly. The author said that brachydactyly was dominant. In the course
of time one would then expect, in the absence of counteracting factors, to get three brachydactylous persons to one
normal, but that was not so. There must be other disturbing factors of equal importance."
8. Yule's Comments Agreed With Others: Speculation by many who were skeptical of the importance
of Mendelism:
-For discrete traits, Mendelism predicted that gene frequencies in populations (and phenotype frequencies) will be
pushed towards certain specific values (because of Mendelian inheritance).
9. For Punnett's Human Examples, He Was Perplexed.: He had no answer to Yule's objec-
tions.
Punnett turned to a friend, G.H. Hardy, one of Britain's most distinguished mathematicians.
Hardy realized that Yule's objection could be answered easily (in fact, he seemed embarrassed by the simplicity).
Hardy was correct, the answer was "simple."
Several investigators independently came up with the answer.
10. William E. Castle: First prominent American Mendelian.
Dealt indirectly with the "Yule" problem in a paper published in 1903.
11. Wilhelm Weinberg: German physician.
Dealt directly with the problem in a paper published (in German) in January 1908.
, EEOB 3310 Exam #3
Study online at https://quizlet.com/_hp2cbx
12. G.H. Hardy: Dealt directly with the problem in a paper published in July 1908.
13. Castle-Hardy-Weinberg Model (1908): W.E. Castle:
One of the founders of genetics in the United States.
Professor at Harvard.
Wrote a paper in 1903 concerning population frequencies of alleles.
-Special case.
Was mentor to a number of students who were influential to American genetics.
--Laurence H. Snyder: One of those who verified the Mendelian inheritance of the PTC "taster" trait. Used his OSU
students, and their families, as the study group.
14. Hardy-Weinberg Model (1908): Simplest model for population genetics.
-Model is based on a foundation of Mendelian inheritance.
Assumptions:
No directive forces.
-No mutation.
-No selection.
-No migration.
No dispersive forces.
-Population infinite in size.
-No non-random mating among individuals.
15. Hardy-Weinberg Principle: Describes the relationship between one generation and the next in terms
of:
genotype frequencies and allele frequencies.
Starting with ANY genotype distribution, the population attains Hardy-Weinberg "equilibrium" in a single generation.
16. Why Is The Population In Stasis?: The answer is the key to population genetics and its use to study
evolution.
17. The Key to Hardy-Weinberg: Genotypes are transient.
-Gentoypes are broken up each generation into gametes.
-Fertilization reconstitutes the gametes randomly into zygotes (new set of genotypes).
18. Why Would Such A Formulation Have Any Importance?: It links generations within the
population.
Study online at https://quizlet.com/_hp2cbx
1. Genomes of A Population: In the genomes of a population of any organism, we known that there are
many "genes" containing considerable levels of variation.
2. Assume we have collected genetic data on the frequency of a trait in a random
sample of the population that we are studying.: What information can we expect to have for
the trait?
-Assume the trait has Mendelian inheritance.
-Assume we can obtain accurate phenotype frequencies.
--Let's initially assume co-dominant inheritance (like piebald spotting in the hair of cats).
-We can start with the phenotype frequencies and then calculate observed genotype and allele frequencies.
3. Piebald Spotting in Cats: Co-dominantly inherited trait.
Two alleles.
-S=white
-s=non-white
Three genotypes.
-SS=>50% white
-Ss=5-49% white
-ss-solid non-white
4. The Null Hypothesis Model for Population Genetics/The Hardy-Weinberg
Model: We need to be able to make some predictions about populations. To do this logically, we need to start from
a null hypothesis.
5. What Is The Hardy-Weinberg Model?
How Did We Get This Model?: Let's put our discussion into the context of science in the first decade of
the 20th Century.
Mendelism has been rediscovered.
Biometricians are feuding with Medelians.
How important are discrete "Mendelian" traits compared to "continuous" Darwinian traits?
Those who believed that Mendelian traits are really important presented their evidence.
One scientist in particular: Reginald Punnett.
, EEOB 3310 Exam #3
Study online at https://quizlet.com/_hp2cbx
6. "Mendelism in Relation to Disease": A presentation by R. Punnett to the Royal Academy of Medicine
(February 28, 1908).
Emphasized the existence of simple Mendelian traits in humans.
-Some of Punnett's examples: Eye color, Brachydactyly.
7. Not So Fast: British statistician, in the audience for Punnett's talk--a "biometrician".
Objected to Punnett's interpretation because of the frequency of traits in the population.
Udny Yule (commenting on Punnett's paper): "Assuming that brown or duplex eye-colour was dominant over blue, if
mating of persons of different eye-colours were random (and that was very nearly true), it was to be expected that in
the population there would be three persons with brown eyes to one with blue; but that was not so. There were more
blues than browns."
"The same applied to the examples of brachydactyly. The author said that brachydactyly was dominant. In the course
of time one would then expect, in the absence of counteracting factors, to get three brachydactylous persons to one
normal, but that was not so. There must be other disturbing factors of equal importance."
8. Yule's Comments Agreed With Others: Speculation by many who were skeptical of the importance
of Mendelism:
-For discrete traits, Mendelism predicted that gene frequencies in populations (and phenotype frequencies) will be
pushed towards certain specific values (because of Mendelian inheritance).
9. For Punnett's Human Examples, He Was Perplexed.: He had no answer to Yule's objec-
tions.
Punnett turned to a friend, G.H. Hardy, one of Britain's most distinguished mathematicians.
Hardy realized that Yule's objection could be answered easily (in fact, he seemed embarrassed by the simplicity).
Hardy was correct, the answer was "simple."
Several investigators independently came up with the answer.
10. William E. Castle: First prominent American Mendelian.
Dealt indirectly with the "Yule" problem in a paper published in 1903.
11. Wilhelm Weinberg: German physician.
Dealt directly with the problem in a paper published (in German) in January 1908.
, EEOB 3310 Exam #3
Study online at https://quizlet.com/_hp2cbx
12. G.H. Hardy: Dealt directly with the problem in a paper published in July 1908.
13. Castle-Hardy-Weinberg Model (1908): W.E. Castle:
One of the founders of genetics in the United States.
Professor at Harvard.
Wrote a paper in 1903 concerning population frequencies of alleles.
-Special case.
Was mentor to a number of students who were influential to American genetics.
--Laurence H. Snyder: One of those who verified the Mendelian inheritance of the PTC "taster" trait. Used his OSU
students, and their families, as the study group.
14. Hardy-Weinberg Model (1908): Simplest model for population genetics.
-Model is based on a foundation of Mendelian inheritance.
Assumptions:
No directive forces.
-No mutation.
-No selection.
-No migration.
No dispersive forces.
-Population infinite in size.
-No non-random mating among individuals.
15. Hardy-Weinberg Principle: Describes the relationship between one generation and the next in terms
of:
genotype frequencies and allele frequencies.
Starting with ANY genotype distribution, the population attains Hardy-Weinberg "equilibrium" in a single generation.
16. Why Is The Population In Stasis?: The answer is the key to population genetics and its use to study
evolution.
17. The Key to Hardy-Weinberg: Genotypes are transient.
-Gentoypes are broken up each generation into gametes.
-Fertilization reconstitutes the gametes randomly into zygotes (new set of genotypes).
18. Why Would Such A Formulation Have Any Importance?: It links generations within the
population.
