BB Bbbb Bb bb Populations: Allele Frequencies

1) Suppose that the frequency of the b allele in the population is.3. a) What is the frequency of the B allele in the population? b) What is the sum of the frequencies of the b and the B alleles?

c) What is the frequency of the bb genotype? d) What is the frequency of the BB genotype? e) What is the sum of the frequencies of cats with genotypes BB or bb?

f) What is the frequency of cats with genotype Bb? g) What is the frequency of cats with genotype bB? e) What is the frequency of heterozygous cats?

f) What is the sum of the frequencies of cats that are BB, bb and Bb?

If p = frequency of first allele, and q = frequency of second allele p 2 + 2pq + q 2 = 1 (Hardy-Weinberg Equation) Frequency of BB Frequency of Heterozygotes (Bb or bB) Frequency of bb

2) Suppose the frequency of B =.2. What are frequencies of the three possible genotypes? frequency (BB) = frequency (bb) = frequency (Bb/bB) =

Do Allele Frequencies Change Over Time? p =.2 q =.8

Hardy-Weinberg Principle: In a population, allele frequencies remain constant in the absence of evolutionary forces Bb bb BB bb Bb

Assumptions of Hardy-Weinberg Principle: Bb bb BB bb Bb 1) Random Mating

Bb bb BB bb Bb 2) No Mutations Assumptions of Hardy-Weinberg Principle: c

Bb bb BB bb Bb 3) Large Population Size

Assumptions of Hardy-Weinberg Principle: Bb bb BB bb Bb 4) No Immigration BB

Assumptions of Hardy-Weinberg Principle: Bb bb BB bb Bb 5) Genotypes have Equal Fitness (= No Natural Selection) ( 2 offspring) (10 offspring) BB (6 offspring)

Assumptions of Hardy-Weinberg Principle: 1)Random Mating 2)No Mutations 3)Large Population Size 4)No Immigration 5)All Genotypes have Equal Fitness (= No Natural Selection) ? How likely is it that a population meets ALL ASSUMPTIONS?

Natural Selection Case Study: Peppered Moth (Biston betularia) Biston betularia var. typicaBiston betularia var. carbonaria DD, Dddd

England: Industrial Revolution

3 4 Explanation?

Forms of Natural Selection in Populations: DIRECTIONAL SELECTION Genotype: BB Genotype: Bb Genotype: bb 24

Forms of Natural Selection in Populations: DIRECTIONAL SELECTION Fig in Molles 2006

Forms of Natural Selection in Populations: DISRUPTIVE SELECTION Genotype: BB Genotype: Bb Genotype: bb 23 24

Forms of Natural Selection in Populations: DISRUPTIVE SELECTION Fig in Molles 2006

Forms of Natural Selection in Populations: STABILIZING SELECTION Fig in Molles Genotype: BB Genotype: Bb Genotype: bb

Fig in Molles 2006 Forms of Natural Selection in Populations: STABILIZING SELECTION

Anoles (Anolis): 150 species in the Caribbean Islands Demonstrating the PROCESS of Adaptation

Observed Relationship of Hind Limb Length to Vegetation in Brown Anoles (Anolis sagrei) 11 Hind Limb Length

15 Brown Anole (Anolis sangrei) Introduction of Brown Anole Populations from Staniel Cay Island to 14 Caribbean Islands (with no preexisting Anole Populations) An Experiment to Test for Adaptive Change

Fig in Molles Years Later..

Fig in Molles Years Later..

Question: Phenotypic Plasticity (= Developmental)? Heritable Trait (with Genetic Basis)?

Possible Lab Experiment to Test for Phenotypic Plasticity versus Heritability of Leg Length

17 Soapberry Bug 18 Species Native to U.S. (3) Species Introduced to U.S. (3) 19 Soapberry Bugs and Plants in Soapberry Family (Sapindaceae) Demonstrating HERITABILITY in Natural Selection

Hypothesis: Beak Length Selected to match Distance to Seed in Fruit 16

Fig in Molles 2008 Size of Fruit in Native and Introduced Soapberries Florida South Central U.S.

Fig in Molles 2008 Observed Relationship between Beak Length and Fruit Radius (Both in FL, TX)

Question: Phenotypic Plasticity (= Developmental)? Heritable Trait (with Genetic Basis)?

Lab Experiment to Test for Adaptive Change Rear Juveniles Bugs with Small Beaks on Large Fruited Species Rear Juvenile Bugs with Large Beaks of Small Fruited Species

Results

Are All Population Changes due to Natural Selection? Chihuahua Spruce Glanville Fritillary Butterfly

US307&q=anolis&hl=en&um=1&ie=UTF-8&sa=N&tab=wi

anolis_carolinensis.jpg /250px-Anolis_sagrei.jpg

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