'Directional selection' presentation slideshows

Lesson Overview

Lesson Overview. 17.1 Genes and Variation. THINK ABOUT IT. Darwin developed his theory of evolution without knowing how heritable traits passed from one generation to the next or where heritable variation came from. What would happen when genetics answered questions about how heredity works? .

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Effects of selection

Effects of selection. The reproductive success of an individual over its lifetime is known as its fitness . When individuals differ in their fitness selection takes place. Measures of Fitness. In practice, fitness can be difficult to measure over an organisms lifetime.

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Evolution Part 1

Evolution Part 1. 1. Who is the naturalist credited for the evolution theory?. Charles Darwin. 2. What is the definition for evolution?. Species change over time. 3. What are the two animals that Darwin studied on the Galapagos Islands and what characteristics did he study?.

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The Genetical Theory of Natural Selection

The Genetical Theory of Natural Selection. Chapter 6. Lecture Outline. Fitness definition Modes and models of selection General model of selection Directional selection Ex: Warfarin Stabilizing selection Ex: Sickle cell anemia and birth weight Diversifying selection

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Points to remember about Natural Selection

Points to remember about Natural Selection. Populations evolve, but individuals do not . I.E., Natural selection acts on the level of the individual, but populations are the smallest unit that can evolve. Natural selection only works on heritable variations , not acquired traits.

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1. Natural Selection Summarized :

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Evolution

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Warm Up 2/27

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A. Organisms do not adapt new traits over their lifetimes.

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Population Evolution: Microevolution

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Chapter 16

Chapter 16. Evolution of Populations. 16-1 Genes and Variation. Darwin and Mendel Genes control heritable traits Changes in genes = variation Natural selection works with this variation. Types of Genetic Variation. Different alleles Dominant, recessive, multiple alleles, etc.

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Speciation & Patterns of Evolution

Speciation & Patterns of Evolution. *. Objectives. Explain how the isolation (physical or genetic) of populations can lead to speciation. *. Vocabualry. Species Speciation Geographic isolation Allopatric Speciation Reproductive Isolation. Sympatric Speciation Gradualism

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Evolution: Microevolution

Evolution: Microevolution. Chapter 16. Microevolution evolutionary changes below species level refers to change within a species changes in gene frequency due to natural selection driving force of evol . Population Genetics study of microevolutionary change

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Hardy-Weinberg p 2 + 2pq +q 2 = 1

Hardy-Weinberg p 2 + 2pq +q 2 = 1 1. A recessive condition occurs in one in every 20000 of a population. What percentage of the population are carriers of the condition?

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Notes, and Journal entry for Monday May 19

Notes, and Journal entry for Monday May 19. Agenda. The journal entry posted at the end of the notes section.

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Evolution Notes

CP Biology Ms. Morrison. Evolution Notes. Genes and Variation. Gene pool = combined genetic information of all members of a particular population Relative frequency = number of times allele occurs in a gene pool (usually %) 2 main sources of genetic variation:

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Evolution Review

Evolution Review. Chapters 22-25. Chapter 22. Decent with Modification Natural selection Evidence that supports Natural Selection Direct observations Fossils Homology Biogeography. Chapter 22. Artificial selection Paleontology Vestigial structures Convergent evolution. Chapter 23.

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KEY CONCEPT Populations, not individuals, evolve.

KEY CONCEPT Populations, not individuals, evolve. Natural selection acts on distributions of traits. . A normal distribution graphs as a bell-shaped curve. highest frequency near mean value frequencies decrease toward each extreme value.

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III. A Closer Look at Natural Selection A. Natural selection, adaptation, and evolution

III. A Closer Look at Natural Selection A. Natural selection, adaptation, and evolution B. Patterns of natural selection 1. Directional selection 2. Stabilizing selection 3. Diversifying selection C. Effects of selection on the distribution of phenotypes. aa. aa. aa. AA.

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