Natural Selection Friday, January 16th, 2014

Do Now Finish worksheet from class I have checked 3 homeworks including today Creating a dichotomous key Taxonomy web Today’s HW Do Now Take out homework What biome is Tennessee in? How do you know? What is the ultimate goal for all living organisms?

Objectives SWBAT describe natural selection by using Darwin’s 5 key points. Essential Question How and why do populations change over time?

Vocabulary Natural Selection Process by which individuals that are better adapted to their environment to survive and reproduce more successfully than less well adapted individuals.

Notes – Natural Selection Over many generations, heritable, adaptable characteristics become more common in a population. This process is called natural selection There are variations within species. Variations are when individuals of the same species are different from others in some of their traits.

Charles Darwin English naturalist Best known for contributions to evolutionary theory 5 points Populations have variation Some variations are favorable More offspring are produced than survive Those that survive have favorable traits A population will change over time

Scenarios Apply Darwin’s 5 points to both statements The picture to the right shows 3 fully grown Giraffes. The longer necks are selected and passed on to future generations. Populations have variation Some variations are favorable More offspring are produced than survive Those that survive have favorable traits A population will change over time

Giraffes Populations have variation Some variations are favorable Long necks vs. Short necks Some variations are favorable Long necks are favorable because they can get more food More offspring are produced than survive Those that survive have favorable traits The long necks will survive more often A population will change over time Over time, the average length of the Giraffes neck will increase because it is a favorable trait

Your turn The Canadian Lynx and the Arctic Hare have a predator-prey relationship. The average speed of both species has increased over a long period of time. Populations have variation Some variations are favorable More offspring are produced than survive Those that survive have favorable traits A population will change over time

Worksheet Please work independently You have 10-15 minutes Be prepared to go over it and share

Answer the Essential Question How and why do populations change over time?

Exit Ticket During a storm, several butterfly eating birds were blown to a distant island. The island, which previously had no birds, was filled with butterflies of all colors. 5 years later, all of the butterflies were either green or brown. What is the process called when certain populations are better adapted and the others will not survive? What are Darwin’s 5 key points and how does this scenario apply to the 5 points?