Evolution WebQuest



Download 63 Kb.
Date14.05.2021
Size63 Kb.
#56627
Webquest Evolution
Gizmo Done

Name ___Ave McCray_________________________________________ Date ___________________ Period ______

Webquest – Mechanisms of Evolution
Part A: Learn about the basics of evolution at http://evolution.berkeley.edu/evolibrary/article/evo_14



  1. ___ ___ Evolution ___ ___ ___ ___ ___ ___ ___ is the process through which modern organisms have descended from ancient ancestors.




  1. This section examines the mechanisms of evolution. Click next. Evolution only takes place when a population experiences a change in… gene frequency within a population over time.


  2. True or False: Only genetic differences that can be passed on are acted upon by evolution. True



  3. Compare the two examples of changes in beetle populations. Which of the two scenarios is an example of evolution? Defend your answer with an explanation. The second example is evolution. The difference in weight in example 1 came about because of environmental influences — the low food supply — not because of a change in the frequency of genes. Therefore, example 1 is not evolution. Because the small body size in this population was not genetically determined, this generation of small-bodied beetles will produce beetles that will grow to normal size if they have a normal food supply.




  1. Click next. Identify and describe the four basic mechanisms for evolutionary change in your own words!

Mechanism

Description

Mutation

A mutation could cause parents with genes for bright green coloration to have offspring with a gene for brown coloration. That would make genes for brown coloration more frequent in the population than they were before the mutation.

Migration

Some individuals from a population of brown beetles might have joined a population of green beetles. That would make genes for brown coloration more frequent in the green beetle population than they were before the brown beetles migrated into it.

Genetic drift

Imagine that in one generation, two brown beetles happened to have four offspring survive to reproduce. Several green beetles were killed when someone stepped on them and had no offspring. The next generation would have a few more brown beetles than the previous generation — but just by chance. These chance changes from generation to generation are known as genetic drift.

Natural selection

Imagine that green beetles are easier for birds to spot (and hence, eat). Brown beetles are a little more likely to survive to produce offspring. They pass their genes for brown coloration on to their offspring. So in the next generation, brown beetles are more common than in the previous generation.




  1. Genetic drift and natural selection only take place if there is __ genetic variation ______________________ ___________________.



  2. Flip through the University of Utah “Learn Genetics” Lab (Recipe for Evolution) to answer the following questions. http://learn.genetics.utah.edu/content/selection/receipe/

  3. What three things make up the “recipe” for Evolution? 1. Variation in living organism 2.inheritance of variation from parents to offspring



  1. Variation

    1. What are two modes of genetic variation of organisms?

  1. __mutation ________________________________________________

  2. __recombination _________________________________________________

https://biologydictionary.net/genetic-recombinatiion/

  1. How would genetic recombination increase genetic variation? Recombination in the form of crossing over occurs between homologous chromosomes, in order to increase genetic diversity by changing the assortment of genes.

    1. Natural Selection

  1. What are three types of selection pressures that could act on and eliminate organisms with undesirable traits? Resource availability ,environmental conditions ,biological factors






  1. Summarize what is happening during natural selection (red/yellow slide).




    1. Explain the role of time in evolution.



  1. Read about Genetic Drift. Summarize the idea behind genetic drift.



  1. How do the finches of the Galapagos Island demonstrate evolution?




  1. Fitness does not necessarily mean “strongest .” Defend this statement.




Download 63 Kb.

Share with your friends:



The database is protected by copyright ©ininet.org 2024
send message
    Main page
next generation