Transcript Day 1
Evolution 2 A: 03/22/10 B: 03/23/10 Warm up 1. What prevents all of the prey from being eaten?” 2. Pick an animal…then list a behavioral and an inherited adaptation 3. Write the definition of adaptation in your own words. 4. What do you know about Natural Selection? 243 Adaptation • Our characteristics are determined by the genes we inherit from our parents • Adaptations are inherited characteristics that increase survival Peppered Moths • Introduction: • Charles Darwin accumulated a tremendous collection of facts to support the theory of evolution by natural selection. One of his difficulties in demonstrating the theory, however, was the lack of an example of evolution over a short period of time, which could be observed as it was taking place in nature. Although Darwin was unaware of it, remarkable examples of evolution, which might have helped to persuade people of his theory, were in the countryside of his native England. One such example is the evolution of the peppered moth Biston betularia. • The economic changes known as the industrial revolution began in the middle of the eighteenth century. Since then, tons of soot have been deposited on the country side around industrial areas. The soot discoloured and generally darkened the surfaces of trees and rocks. In 1848, a dark-coloured moth was first recorded. Today, in some areas, 90% or more of thepeppered moths are dark in colour. More than 70 species of moth in England have undergone a change from light to dark. Similar observations have been made in other industrial nations, including the United States. Peppered Moths Investigation • We need to design an experiment around the peppered moth simulation. Take a few minutes to brainstorm. Here are some things to think about: • What question do you want to ask about this investigation of peppered moth population? • What is your hypothesis? • What are some important parts of this procedure? • What is the dependant variable and independent variable? • What data should we collect? How should we collect it? Peppered Moth Simulation • http:/www.biologycorner.com/worksheets/pepperedmo th.html • Objective: Simulate changes in moth population due to pollution and predation, and observe how species can change over time. Instructions: You will run two simulations for 1 minute each, during this time you will play the part of a bluejay that eats moths. After 1 minute record (on scratch paper) the % of dark moths and light moths - you will need this information later. • Run Lichen (light colored) forest • Run Soot (dark colored) forest 1. Record the moth population percentages. 2. Repeat steps 2-5 for each trial. 3.Analysis - answer all questions on the analysis page. Data Table • Create a data table that allows you to record your data about the moth population. • You will need to record each trial as well as what the background color of the tree was. Definition Independent Variable Dependent Variable Hypothesis Control Constants Moth Experiment Trial 1 2 3 Moth Survival Light Forest Moth Survival Dark Forest Natural Selection Natural Selection--Mechanism for evolution (change over time) 1. Genetic Variation—organisms have different features determined by different genes 2. Survival of the Fittest—organisms with traits that “fit” with their environment survive 3. Reproduction—organisms who survive reproduce and have offspring with the same traits Analysis Questions (1). Explain how the color of moths increases or decreases their chances of survival depending on the environment. (2). 500 light colored moths and 500 dark colored moths are released into a polluted forest. After 2 days the moths were recaptured, make a prediction about the number of each type of moth that would be captured. • (3). How has the striking change in coloration come about? (Include an explanation of how the dark moth appeared and how the proportion of dark moths changed from 0.0005% to more than 90% in polluted forests.) • (4). What underlying law of nature has produced this change? (Use Darwin's theory of evolution and apply it to what you have learned in this investigation.) Natural Selection Natural Selection--Mechanism for evolution (change over time) 1. Genetic Variation—organisms have different features determined by different genes 2. Survival of the Fittest—organisms with traits that “fit” with their environment survive 3. Reproduction—organisms who survive reproduce and have offspring with the same traits • Genetic variation results in variation in traits • Over time, DNA changes by mutation • Bill Nye’s Video: Evolution • Guided reading Charles Darwin and Natural Selection Galapagos Islands One of the animals Darwin encountered were finches, a type of bird. They exhibited a wide range of beak shapes and sizes. On your notebook, please write down and answer the following question: How is it possible for these different beaks to exist on a few tiny islands? Or Why do these birds have different beaks… Honey Bee BCR • The honey bee in American may develop immunity to the mites over time, because of _Natural Selection. • 1. Genetic Variation • 2.Surrvival of the fittest • 3. Reproduction Acknowledgement This powerpoint presentation is partly adapted from Steven Craig at Northwood HS.