Natural Selection and Adaptations What’s up with that bird?

Vocabulary Adaptation Natural Selection Mutation

Scientists believe that the Earth and its inhabitants have changed a great deal over time. -They have observed species’ fossil records and have noticed changes over time. -Organisms tend to adapt or change over time.

2. Adaptation- a change in an organism that helps it live and reproduce successfully in its environment. -these adaptations can be physical or behavioral long neck or stripes Reproduction, protection, or finding food http://www.lawrencehallofscience.org/kidsite/portfolio/build-a-fish/

3. One scientist that observed these kinds of differences in plants and animals of the same species is Charles Darwin.                                            

In 1831 Darwin sailed on board the SS Beagle from his home in England to a small island group off the coast of Ecuador

4. Darwin traveled to the Galapagos islands where he saw plants and                                                                                                                                  4. Darwin traveled to the Galapagos islands where he saw plants and animals that differed from those on other islands and the mainland.                                             Examples: tortoises long neck versus short neck Live in dry climates with cacti Live in damp area with abundant plant life

5. Darwin also found different types of finches (birds). He noticed different beak shapes and sizes from one island to the next.                             Woodpecker finch Vegetarian finch Large ground finch Cactus finch

Darwin’s Finches Adaptation occurs in an ecosystem so that species can better survive in their habitat. Sometimes these adaptations cause competition between species allowing one species to thrive while the other dies out. A good example of this type of adaptation occurs on the Galapagos Islands with the finches that inhabit the area. Each species of finch has a specific body weight, beak shape and eating habits that allows them to avoid competing for food with the other finches.

There are at least 13 species of finches, each with a different niche. All are said to have come from the same ancestral species, which only got to the islands about 2 million years ago. This is known as adaptive radiation-where one species quickly changes or adapts to fill in the “empty” ecospace.

6. When most plants and animals reproduce, they usually produce more offspring than can survive. Example: salmon -lay 1000’s of eggs, but not all will hatch. Of those that do hatch, only a fraction will survive disease and avoid fish eating predators. Only a small % of these survivors will make it to adulthood, with only a few being able to reproduce successfully.

7. From one generation to the next there are always variations. These genetic variations are passed down. http://phet.colorado.edu/en/simulation/natural-selection -run now version 8. A change in genetic material is called a mutation. Some mutations make the individual better able to survive.

Camouflage an adaptation or a mutation? -Moths will rest during the day Time: late 18th/early 19th century Place: Pre-industrial England Subject: Biston betularia or the peppered moth -Black moth coloration considered a mutation Before industry-trees had gray trunks-gray moths blended in better. After industry developed-tree trunks turned black due to the pollution from factories-black moth was then able to blend in After many, many generations of this, most moths were then black. In this case coloration is considered to be an adaptation.

Moths

Introduction: Industrial Melanism is a term used to describe the adaptation of a population in response to pollution. One example of rapid Industrial Melanism occurred in populations of peppered moths in the area of Manchester, England from 1845 to 1890. Before the industrial revolution, the trunks of the trees in the forest around Manchester were light grayish-green due to the presence of lichens. Most of the peppered moths in the area were light colored with dark spots. As the industrial revolution progressed, the tree trunks became covered with soot and turned dark. Over a period of 45 years, the dark variety of the peppered moth became more common.

9. If this organism is able to survive and reproduce, the mutation is passed on to future generations. This is called selective breeding http://www.pbs.org/wgbh/nova/evolution/evolution-action.html Example: Terriers bred to show certain characteristics

10. This idea led to the Darwin’s theory on Natural Selection. 11. Natural Selection: the process by which organisms that are best suited to their environment survive and reproduce. Example: small marine iguana on an island with a thin layer of algal growth http://media.nclive.org/authvid.phtml?vid=203&ctime=6 Voyage to the Galapagos video and questions (~60 minutes)

Who wants to live a million years? http://science.discovery.com/interactives/literacy/darwin/darwin.html

http://biologyinmotion.com/evol/index.html Evolution Lab In this lab, you will use a computer simulation to track a population of organisms as they evolve. You will take data on the number and varieties of the organisms and graph them to show change over time and determine how two factors: MUTATION RATE and SELECTION STRENGTH affect how populations evolve. Instructions 1. Go to www.biologyinmotion.com and click on the link that says "evolution lab" 2. Read the introduction and the contents to learn about the imaginary creatures you will be studying and how to operate the simulator. You may also want to look at the help link. 3. Open the simulator and practice using the controls before you go on to the real simulation. Be sure to "reset" the simulator when you're finished practicing. http://biologyinmotion.com/evol/index.html

Fill out the data table and create a graph for simulation B. Simulation A - The purpose of this simulation is to determine how the mutation rate affects the evolution of your population. You will need to run 4 trials with varying settings for mutation rate. Fill out the Data Table and create a graph using the graphing program at . You will have 4 lines on your graph. The X-axis will be cycles, and the Y will be mean phenotype. Simulation B - The purpose of this simulation is to determine how selection strength affects the evolution of your population. Run three trials with the selection strength at 0, and three trials with the selection strength at varying ranges. (See data table) Fill out the data table and create a graph for simulation B. Graphing Program located at: http://www.nces.ed.gov/nceskids/graphing Blank Data Tables (doc)