Unit 5 Day 3 Evolution of Populations

Unit 5 Day 3 Evolution of Populations

• Populations are a mix of individuals with different traits

• Some traits are more desirable than others​

• ​This leads to adaptation

• NEW genetic variation occurs as a result of MUTATIONS​

Genetic Variation is what drives Natural Selection​

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​Population- a group of organisms of the SAME species living in the SAME place at the SAME time

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Evolution occurs within populations​!

Multiple Choice

Which of the following is the best example of a population?

• The current residents of Seneca, SC

• A pond containing 5 different species of fish

• All of the humans on Earth

• 5 generations of chickens on a farm

The Hardy-Weinberg ​Principle

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How can we measure if/how much a population is evolving? ​

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​Assume there are 2 alleles: A and a

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​p = the frequency of the dominant allele, in decimal form

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q = the frequency of the recessive allele, also in decimal form​

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• p + q = 1​, because the frequencies MUST add up to 100

​Lets try a problem together

Given a population, at Hardy-Weinberg equilibrium, the frequency of the dominant allele A = 0.9. What are the frequencies of Homozygous Dominant, Heterozygous, and Homozygous recessive individuals in the population?​

• Hardy-Weinberg Equilibrium is a hypothetical, non-existent, non-evolving population ​

  • No changes in allele frequency = no evolution

• Useful for research, serves as a model

  • Helps us see if, and to what degree evolutionary "forces" are acting on a population​

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What is Hardy-Weinberg Equilibrium?​

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​G.H. Hardy

​W. Weinberg

Any Questions?​