Lab: Evolution

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In lab this week we are going to revisit the topic of evolution. This is a key component to our understanding of SARS-CoV2 and other emerging diseases, so it is well worth spending the extra time on it.  Below you will find a refresher of the information we covered in class.  In lab we will conduct the exercise from the lab textbook  ( page 61: Evolution and Natural Selection),  You will each need to submit the assignment at the bottom of this page.

Evolution- Refresher 

  You watched this video below, and should have a gotten the following explanation 

Question 

Answer 
What is evolution?  Change in the gene pool over generations 
What is a gene pool ?  All of  the genes from all of the individuals in a population
 What reshuffles genetic information from generation to generation?  Sexual reproduction: since  offspring inherit a mixture of their parents' genes
What are  different mechanisms that can lead to evolution? Natural selection, mutation, sexual reproduction, ( I'm only referring to these - there are others) 
Which of these leads to adaptations?  Natural selection 
What is an adaptation?  Heritable trait that helps the organism survive and/or survive 

What is natural selection in terms of genes, variations and adaptation to environment?

  organisms better adapted to their environment tend to survive and produce more offspring.
Which of these introduces new genes?  Mutation 

 

 

 

 

Natural Selection- Refresher  

In lab we are going to focus on natural selection. This is defined as  'as a difference in the survival and reproduction of individuals in a population' . I can think of this as ''Nature'' or the environment selecting which individuals do better than others and therefore survive and reproduce. For natural selection to occur there needs to be

  • Genetic variation in the population
  • A difference in survival and reproduction between these variants

Sources of Genetic Variation - Refresher 

There are two main sources of genetic variation that we have examined:

  • sexual reproduction
  • mutations.

Sexual reproduction reshuffles genetic traits and is very important when talking about the evolution of eukaryotes. But viruses and bacteria are much more influenced by mutations.  Remember what we learned about mutations:

  • a mutation can have no impact on the function of a protein
  • a mutation can have  a small impact on the function of a protein
  • a mutation can have a large impact on the function of a  protein  

This depends on which nucleotide is affected and therefore which amino acid is affected. It is essentially random .

 

Evolution Lab Assignment 

 

In lab we did a an activity to simulate natural selection on a population of Jelly-Belly organisms that were living/hiding in a habitat of Seed-Soil.

  1. After lab, you will use this link to access the class data: Evolution and Natural Selection Data Analysis . Links to an external site.
  2. Follow  the instructions in this video to analyze the data and create 3 graphs

 

  1. Answer the following questions
  2. What was our  hypothesis?
    • What did we predict would happen to the population of jelly beans on each of the different soil types?
    • Did our results match our predictions?
    • Insert your graphs and refer to them to justify your answer. 
  3. Which phenotypes did better on which soil? Why?
  4. Would you expect the results to be different if we had started with more black jelly beans?  Explain 
  5. If the jelly beans are stand-ins for  the virus, what do the different colors represent? 
  6. What are the sources of new ''colors'' of the virus?
  7. What determines if the virus survives and reproduces? 
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