KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.

Slides:



Advertisements
Similar presentations
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
Advertisements

KEY CONCEPT New species can arise when populations are isolated.
How do we know if a population is evolving?
Chapter 16 Table of Contents Section 1 Genetic Equilibrium
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT A population shares a common gene pool.
The Hardy-Weinberg Equilibrium
Gene flow is the movement of alleles between populations.
KEY CONCEPT A population shares a common gene pool.
KEY CONCEPT A population shares a common gene pool.
Evolution as Genetic Change and Speciation. A Population’s Gene Pool A gene pool is all the alleles available in all of the individuals in a population.
Maintaining Genetic Variation (Population Equilibrium) Populations have TWO competing factors: Remaining stable (not evolving) vs Changing (evolving)
Population Genetics and Speciation
How do we know if a population is evolving?
BIOZONE: due Wed 11/05 BIOZONE: due Wed11/05
Chapter 11 Biology Textbook
Evolution and Population GENETICS
Chapter 16 Population Genetics and Speciation. Objectives CLE Explain how genetic variation in a population and changing environmental conditions.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
Measuring Evolution of Populations. 5 Agents of evolutionary change MutationGene Flow Genetic Drift Natural Selection Non-random mating.
Meet My Good Friends Hardy and Weinberg!! Biologists use models to study populations. Biologists use models to study populations. Hardy and Weinberg.
Chapter 11: Evolution of Populations
Populations, Genes and Evolution
Natural Selection Bio Explain how natural selection influences the changes in species over time Bio Explain how various disease agents (bacteria,
KEY CONCEPT A population shares a common gene pool.
Equilibrium, Speciation and Patterns in Evolution
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
What we know….
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
Evolution as genetic change
Measuring Evolution of Populations
Measuring Evolution of Populations
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT Hardy-Weinberg equilibrium is a mathematical/statistical equation for understanding how populations evolve.
HMD Bio Chapter 11 Section 4 KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
The Evolution of Populations
15.3 PDQ.
Population Genetics.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
How Populations Evolve
KEY CONCEPT New species can arise when populations are isolated.
HARDY-WEINBERG and GENETIC EQUILIBRIUM
March 26th and 27th , 2018.
Hardy Weinberg: Population Genetics
Equilibrium, Speciation and Patterns in Evolution
Chapter 11 Biology Textbook
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
1. Sexual Selection In order for random mating to occur, all members of the population must have equal.
KEY CONCEPT New species can arise when populations are isolated.
Chapter 16 Table of Contents Section 1 Genetic Equilibrium
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT New species can arise when populations are isolated.
Allele frequencies when populations are NOT evolving
11.1 Genetic Variation within Popln
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT New species can arise when populations are isolated.
Hardy-Weinberg Equilibrium and The Process of Speciation
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
KEY CONCEPT New species can arise when populations are isolated.
KEY CONCEPT New species can arise when populations are isolated.
KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.
How Populations Evolve
KEY CONCEPT New species can arise when populations are isolated.
Hardy-Weinberg Lab Data
Presentation transcript:

KEY CONCEPT Hardy-Weinberg equilibrium provides a framework for understanding how populations evolve.

Hardy-Weinberg equilibrium describes populations that are not evolving. Biologists use models to study populations. Hardy-Weinberg equilibrium is a type of model.

Hardy-Weinberg equilibrium describes populations that are not evolving. Genotype frequencies stay the same if five conditions are met. very large population: no genetic drift no emigration or immigration: no gene flow no mutations: no new alleles added to gene pool random mating: individuals pair by chance instead of their genotype/phenotype no sexual selection no natural selection: all traits aid equally in survival

Hardy-Weinberg equilibrium describes populations that are not evolving. Real populations rarely meet all five conditions. Real population data is compared to a model. Models are used to studying how populations evolve.

Predicted genotype frequencies are compared with actual frequencies. The Hardy-Weinberg equation is used to predict genotype frequencies in a population. Predicted genotype frequencies are compared with actual frequencies. used for traits in simple dominant-recessive systems must know frequency of recessive homozygotes p2 + 2pq + q2 = 1 "The Hardy-Weinberg equation is based on Mendelian genetics. It is derived from a simple Punnett square in which p is the frequency of the dominant allele and q is the frequency of the recessive allele."

Genetic drift changes allele frequencies due to chance alone.

Gene flow moves alleles from one population to another.

Mutations produce the genetic variation needed for evolution.

Sexual selection selects for traits that improve mating success.

Natural selection selects for traits advantageous for survival.

In nature, populations evolve. expected in all populations most of the time respond to changing environments http://www.sciencegeek.net/Biology/Powerpoints/HardyWeinberg.ppsx

Hardy-Weinberg Lab Data Mutation Gene Flow Genetic Drift Selection Non-random mating 2006-2007

Hardy Weinberg Lab: Equilibrium Original population Case #1 F5 18 individuals 36 alleles p (A): 0.5 q (a): 0.5 total alleles = 36 p (A): (4+4+7)/36 = .42 q (a): (7+7+7)/36 = .58 AA 4 Aa 7 aa 7 AA .25 Aa .50 aa .25 AA .22 Aa .39 aa .39 How do you explain these data?

Hardy Weinberg Lab: Selection Original population Case #2 F5 15 individuals 30 alleles p (A): 0.5 q (a): 0.5 total alleles = 30 p (A): (9+9+6)/30 = .80 q (a): (0+0+6)/30 = .20 AA 9 Aa 6 aa AA .25 Aa .50 aa .25 AA .60 Aa .40 aa How do you explain these data?

Heterozygote Advantage Hardy Weinberg Lab: Original population Case #3 F5 15 individuals 30 alleles p (A): 0.5 q (a): 0.5 total alleles = 30 p (A): (4+4+11)/30 = .63 q (a): (0+0+11)/30 = .37 AA 4 Aa 11 aa AA .25 Aa .50 aa .25 AA .27 Aa .73 aa How do you explain these data?

Heterozygote Advantage Hardy Weinberg Lab: Original population Case #3 F10 15 individuals 30 alleles p (A): 0.5 q (a): 0.5 total alleles = 30 p (A): (6+6+9)/30 = .70 q (a): (0+0+9)/30 = .30 AA 6 Aa 9 aa AA .25 Aa .50 aa .25 AA .4 Aa .6 aa How do you explain these data?

Hardy Weinberg Lab: Genetic Drift Original population Case #4 F5-1 6 individuals 12 alleles p (A): 0.5 q (a): 0.5 total alleles = 12 p (A): (4+4+2)/12 = .83 q (a): (0+0+2)/12 = .17 AA 4 Aa 2 aa AA .25 Aa .50 aa .25 AA .67 Aa .33 aa How do you explain these data?

Hardy Weinberg Lab: Genetic Drift Original population Case #4 F5-2 5 individuals 10 alleles p (A): 0.5 q (a): 0.5 total alleles = 10 p (A): (0+0+4)/10 = .4 q (a): (1+1+4)/10 = .6 AA Aa 4 aa 1 AA .25 Aa .50 aa .25 AA Aa .8 aa .2 How do you explain these data?

Hardy Weinberg Lab: Genetic Drift Original population Case #4 F5-3 5 individuals 10 alleles p (A): 0.5 q (a): 0.5 total alleles = 10 p (A): (2+2+2)/10 = .6 q (a): (1+1+2)/10 = .4 AA 2 Aa 2 aa 1 AA .25 Aa .50 aa .25 AA .4 Aa .4 aa .2 How do you explain these data?

Hardy Weinberg Lab: Genetic Drift Original population Case #4 F5 5 individuals 10 alleles p (A): 0.5 q (a): 0.5 AA Aa aa p q 1 .67 .33 0 .83 .17 2 0 .8 .2 .4 .6 3 4 .4 .2 .6 .4 AA .25 Aa .50 aa .25 How do you explain these data?

SPECIATION KEY CONCEPT New species can arise when populations are isolated.

The isolation of populations can lead to speciation. Populations become isolated when there is no gene flow. Isolated populations adapt to their own environments. Genetic differences can add up over generations.

Reproductive isolation can occur between isolated populations. members of different populations cannot mate successfully final step to becoming separate species Speciation is the rise of two or more species from one existing species.

Populations can become isolated in several ways. Behavioral barriers can cause isolation. called behavioral isolation includes differences in courtship or mating behaviors

Geographic barriers can cause isolation. called geographic isolation physical barriers divide population Temporal barriers can cause isolation. called temporal isolation timing of reproductive periods prevents mating