Catalyst: September 15th, 2014 (5 minutes)

Finish the questions on your Adaptations notes (Unit 2, Assignment 1).

Today’s AgendaCatalyst (5 minutes)Evolution & Natural Selection (15

minutes)Peppered Moth Demonstration/Analysis

Questions (Remainder)

Homework: Natural Selection video 9/18 DBA #5: 9/29 HP 9/26

Announcements

DojoNo school for you Friday! Natural selection and adaptations quiz on Wednesday

Objectives

SWBAT define evolution SWBAT explain Charles Darwin’s theory of

evolution by natural selection in their own words

SWBAT describe the role of genetic variation and adaptation in the process of evolution by natural selection

SWBAT identify examples of natural selection and explain how they demonstrate natural selection

SWBAT demonstrate the process of natural selection through an inquiry demonstration.

Unit 2: Guiding Questions

What determines which organisms survive and which do not?

Do species ever change?How do scientists believe all of the

species that exist today were formed?

What evidence is there to support evolution?

Evolution & Natural Slection

BiologyUnit 2Section 15.1

What do you think?

Have the species of organisms (bacteria, plants, animals, humans) that exist today always existed?

Are they exactly the same as they were many years ago?

OR have organisms changed over time and have new species of organisms appeared?

Key Point 1: What is artificial selection?

Humans have been manipulating other animals and plants for many years.

Think of different breeds of dogs: Pitbulls, Rottweiler, Dachshunds, Bulldogs, Labrador

Key Point 1: What is artificial selection?

Artificial selection or selective breeding occurs when humans breed other animals and plants for specific and desired traits (examples: Dogs, horses, vegetables).

However, organisms have been changing for millions of years.

Key Point 2: What is evolution? This topic was studied by

a scientist named Charles Darwin

Darwin studied plants and animals throughout South America and the breeding of animals in England Finches Artificial breeding

Darwin’s Findings

From his studies, Darwin determined that groups of organisms can and do change over time Evolution!

He proposed that sometimes these changes may even lead to the appearance of new species

What is Evolution?

Evolution is the gradual change in a population of organisms over time Population=all organisms of a species in

one area Charles Darwin and many scientists have

since agreed that this happens in nature

Evolution of Populations

Individual organisms do not evolve. Instead, evolution occurs in populations.

Key Point 3: How does evolution happen?

Charles Darwin concluded that evolution often occurs through a process known as natural selection

There are 4 main principles of natural selection

Principles of Natural Selection

Natural Selection1. All organisms in a population have

different traits due to genetic variation

Genetic Variation = differences in DNA and traits

Example: Most deer mice in North America are dark brown, but some are light brown

Example of Natural Selection

Why are all deer mice in Sandhills, Nebraska light brown?

Let’s look at what happened…

Principles of Natural Selection

2. Not all organisms in a population can survive. Organisms with adaptations to their environment are most likely to survive and reproduce

Review: What are adaptations? Which mice do you think survived more

easily in the sandy hills? Why? Example: Light brown color was an

adaptation (camouflage), so these mice survived

Principles of Natural Selection

3. Organisms that survive and reproduce pass on the genes for their adaptations

Example: The few light brown mice had more time to survive and reproduce. They passed on the gene for light brown color to their offspring.

Principles of Natural Selection

4. Eventually all organisms in the population inherit the genes and express the adaptation

How did the deer mice population evolve?What do you think the population is

today?Example: Over time, all of the deer mice

born were light brown. Today, the whole population of deer mice in the sandy hills in Nebraska is light brown

Natural Selection & Evolution Over time, adaptations are inherited by

all organisms in a population Organisms with specific adaptations are

“naturally selected” Natural selection causes a population to

evolve, but it may or may not create a new species The deer mice population evolved from

almost all dark brown mice to all light brown mice.

However, this did not form a new species

Key Point 4: Sexual Selection

Evolution also occurs through sexual selection in which members of the same species must compete for a mate in order to successfully pass on genes.

Key Point 4: Sexual Selection

http://www.bing.com/videos/search?q=birds+of+paradise+mating+dance&go=&qs=bs&form=VBREQY#view=detail&mid=591C6AB5C5DA7F0168CF591C6AB5C5DA7F0168CF

Real World Examples

African elephants typically have large tusks. The ivory in the tusks is highly valued by some people, so hunters have hunted and killed elephants to tear out their tusks and sell them (usually illegally) for decades. Some African elephants have a rare trait -- they never develop tusks at all. In 1930, about 1 percent of all elephants had no tusks. The ivory hunters didn't bother killing them because there was no ivory to recover. Meanwhile, elephants with tusks were killed off by the hundreds, many of them before they ever had a chance to reproduce.

. The result: As many as 38 percent of the elephants in some modern populations have no tusks [source: BBC News]. Unfortunately, this isn't really a happy ending for the elephants, since their tusks are used for digging and defense.

Example: Insects

Pesticides are chemicals used to kill insects that eat crops. Most insects are not pesticide-resistant (protected), but some insects are pesticide-resistant

What is the cause of these differences?? Genetic variation! (different genes)

Example: Insects

When farmers spray pesticides on their crops, most of the insects that eat the crops will not survive.

What trait would be an adaptation?Pesticide-resistanceWhich insects will NOT survive?

Example: Insects

What do the organisms with the adaptation do?

Insects with pesticide resistance reproduce and pass on genes for pesticide-resistance to their offspring

What happens to the rest of those without the adaptation?

More of the insects without pesticide resistance die as farmers continue to spray the crops

Example: Insects

Eventually what happens? What trait do all of the surviving

insects have? All surviving insects are pesticide-

resistant How did the population evolve?

From being mostly not pesticide-resistant to being all pesticide resistant

What is this process called? Natural selection!

What problems might this cause for farmers?

Example: Bird Beaks

Most birds on an island have fragile, thin beaks and a few have strong, thick beaks.

What is the cause of these differences?? Genetic variation!

Peppered Moths Demo

Chunk 1: Parent Generation

Chunk 2: Environmental disturbance

Chunk 3: Generation 1 Chunk 4:

Remainder/Analysis

Expectations: Follow along with the

procedures

Catalyst: September 16th, 2014 (5 minutes)

1.We will be watching a short video clip.

2.You need to write at least three points from the video on your Catalyst paper as you watch.

Agenda

Catalyst: 12 minutes Evolution of Bird Beaks Lab: 20 minutes Natural Selection Case Studies: Remainder

Reminders: Natural Selection Homework DBA #5 9/29 HP 9/26 Edmodo video 9/18

Announcements

Natural Selection quiz on Wednesday

Battle of the Beaks

Procedures 1. Ms M. will assign you to a station. Each station represents a different food

source. 2. As a group decide which feeding implement each member will have. Each

group member should have a different feeding implement and a Dixie cup. 3. You are now a very hungry bird. The tool you have selected is your “beak”.

You can only use your beak to pick up food. 4. The cup is your stomach. It must remain upright at all times. You must hold

your beak in one hand and your stomach in your other hand, close to your body. Only food that is placed in the cup by the beak has been “eaten”. No scooping is allowed and no fighting over food with other birds.

5. When Ms. M says “Go” you will have 30 seconds to feed (or until the food runs out). Collect as much food in your stomach as possible until Ms. M says “Stop”.

6. When Ms. M says “Stop”, you will empty your stomach and count the contents. Record data in the Individual Data Table. Replace food items.

7. Rotate to a new station upon Ms. M’s instruction. You may bring your beak with you!

8. Continue steps 4-7 until each group has visited each food station.

Lab Expectations

Do not interfere with others’ lab materials.

Keep the same feeding implement (even if your’s does not work particularly well-that’s the fun part!)

Remain at your station until directed to move.

Analysis and Case Study

Answer the case study questions INDEPENDENTLY. If you finish early, you may begin on your homework.