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

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Presentation on theme: " Finish the questions on your Adaptations notes (Unit 2, Assignment 1)."— Presentation transcript:

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

2  Catalyst (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

3 Dojo No school for you Friday! Natural selection and adaptations quiz on Wednesday

4  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.

5  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?

6 Biology Unit 2 Section 15.1

7  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?

8  Humans have been manipulating other animals and plants for many years.  Think of different breeds of dogs: Pitbulls, Rottweiler, Dachshunds, Bulldogs, Labrador

9  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.

10  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

11  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

12  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

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

14  Charles Darwin concluded that evolution often occurs through a process known as natural selection  There are 4 main principles of natural selection

15 Natural Selection 1. 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

16  Why are all deer mice in Sandhills, Nebraska light brown?  Let’s look at what happened…

17 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

18 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.

19 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

20  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

21  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.

22  http://www.bing.com/videos/search?q=birds+ of+paradise+mating+dance&go=&qs=bs&for m=VBREQY#view=detail&mid=591C6AB5C5 DA7F0168CF591C6AB5C5DA7F0168CF

23 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.

24 . 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.

25  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)

26  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-resistance  Which insects will NOT survive?

27  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

28  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?

29  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!

30  Chunk 1: Parent Generation  Chunk 2: Environmental disturbance  Chunk 3: Generation 1  Chunk 4: Remainder/Analysis  Expectations:  Follow along with the procedures

31 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.

32  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

33  Natural Selection quiz on Wednesday

34  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.

35  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.

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


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