Agenda – March 3 Population Notes Ch 23 Section 1 and 2 Hardy Weinberg Practice Worksheets HW: Finish Lab 8 and 9 Field Trip Forms and Money Due March 11th

Review 1. These terms are not the same, they are not interchangeable. What is your definition? Natural selection? Adaptation?

Natural Selection Natural selection is the PROCESS that results in evolution. It "screens" traits that are available. It doesn’t create new traits. It favors those characteristics that fit the specific current environment. Adaptation is the change or the trait that occurs over time so an organism fits better with its environment.

Population Genetics and Speciation Population Genetics and Speciation * Natural Selection works on individuals but is only apparent in a population as it changes over time* Ch 23 Sec 1 and 2

Microevolution: Change in allele frequency of pop/gen Natural Selection (Consistent matches env/org) Genetic Drift (Chance) Gene Flow (Between populations) Gene Pool: all alleles for all loci in a population

The factors create genetic variation - makes evolution possible. Recombination and RNA Splicing: Genes are shuffled Random pairing of gametes: Which sperm will be the winner? Mutations Environmental effects Crossing Over/Ind Assortment: Meiosis Cause phenotypic differences.

Characters that vary can be: Discrete: purple, white flowers (one gene) *** Quantitative: continuum, (multi genes)

Mutations Ultimate source of new alleles Somatic/Body cell – not inherited Gamete/Germ cell – inherited change Point and frameshift 1 in 100,000 genes per generation (plant and animal) Less for prokaryotes ^reproduction ^rate HIV, 2 Days, No Repair Mechanisms

Hardy Weinberg Used to assess if natural selection causing evolution or other factors (If it is not evolving, HW applies)

PKU (Recessive Metabolic Disorder) Affects 1 out of 10,000 babies in USA Assume: No new PKU mutations introduced (Condition 1) No preferential mating bcuz of disorder (Condition 2) No differential survival and reproductive success among PKU genotypes (Condition 3) Large population, no genetic drift or gene flow (Conditions 4 and 5) Reasonable assumptions for this disorder

Practice Question Recessive = q2 = 1 in 10,000 = .0001 Therefore, q = .01 Frequency of dominant allele = p = 1- q = .99 We have to calculate number of heterozygotes. 2pq = .0198 or approximately 2% of USA population

Independent Practice Worksheet Homework: Lab 8 and 9 Due Tmrw Independent Practice Worksheet

March 4, 2016 Agenda: Turn in Lab Journal Finish Chapter 23 Notes Teddy Graham Activity HW: Practice Ques. Wrksht and Video Notes

Hardy Weinberg Answers q=.6 p=.4 2pq=.48 Frequency of homozygous dominant 16% 3. 2pq = .48 q=.6 p= .4 48% 36% 16% 4. Homo Recessive 81%, Homo Dominant 1%, Hetero 18% Frequency of Dom 10%, Frequency of Recessive 90% 5. Dominant phenotype 91%, recessive phenotype 9%, Heterozygous 42% (This group is part of the dominant group)

Recall from Yesterday… Three processes can change allele frequency. What are they?!

Genetic Drift Chance events can cause ∆ allele freq., Unpredictable, Esp. in small popu. Fertile soil? Nutrients available? Sunlight? Wild moose?

Certain chance events have sig. impact Bottleneck Effect - Reduction (Disease, Disaster) Founder Effect – Increase (Colonization)

Greater Prairie Chicken 19th- 20th Centuries Human Impact: Illinois Prairies to Farms Dec. popu., genetic variation < 50 ckns between 2 popu. < 50% Eggs hatching (^ harmful alleles) Translocation, add new alleles

Gene Flow In/Out Population (Travel) Blending of popu. Introduce new alleles Higher rate than mutations Alter allele freq. ^ v Blending of popu. Combine single popu. Common gene pool Ex: Insecticide-Resistant mosquitoes worldwide

Natural Selection can alter heritable traits in 3 ways… Favors one extreme (Large body size of bears, conserving body heat, survive winter) Favors both extreme phenotypes (Sm beaks soft food and Lrg beaks for hard food) Favors Intermediate (Birth Weight 6.6-8.8 lbs) Reduces variation

Then why aren’t all living things perfect? NOT GOAL ORIENTED. Acts on existing variations, may not be ideal, can’t demand needs Limited historical constraints, ancestral anatomy Adaptations often compromises (Opposable thumbs) Nat. Sel. Interacts with Env. And Chance (Unpredictable, Limiting)

Teddy Bear Activity Groups of 3 DO NOT EAT OR INJURE THE BEARS