1. Mind Stretcher 5-1-18 What observations can you make about these two snakes? List 3 things.
Rough Green Snake
Corn Snake

2. Notes: Natural Selection
Use big organizer provided to take your notes…You only get ONE, so do not lose it and use pencil!

3. Natural Selection
What is Natural Selection? -PROCESS by which individuals better adapted to their environment are more likely to survive and reproduce than other members of the same species.

4. Natural Selection
What is “Fitness”? (“Survival of the fittest!”) It’s the ability of something to survive; An indication of how well it is suited for its environment. It’s NOT necessarily the biggest or strongest!
Who's Going to Survive?

5. Charles Darwin & Theory of Natural Selection…
British Naturalist aboard the ship, HMS Beagle
Traveled to Galapagos Islands
Collected animal & plant samples
Noticed variations among species…tortoise, finches, etc.
Devised theory of natural selection
Wrote about it in his book, Origin of the Species

6. Key Vocabulary to Understand:
Adaptation- a characteristic that helps an organism survive and reproduce in its environment
Examples of Adaptations: Hibernation, camouflage, migration, hair, & resource conservation (don’t write these yet!)

7. Camouflage
The ability to blend into the surrounding environment is helpful when avoiding predators
Examples:
Scorpionfish and leaf frogs- can change their appearance to match their surroundings.
Walking stick- looks very much like a twig
Zebras fool “would-be” predators;
To a lion, they may look more like a mass of black-and-white stripes than a delicious prey species!

8. Hibernation
When animals “sleep” through the winter to escape the cold and because food is scarce.
EX: chipmunks, hedgehogs, bats and bears. (It’s usually quite difficult to stir these animals during hibernation!)

9. Migration
Movement of an animal population from one place to another to find food or place to mate.
Example- the arctic tern makes an annual migration from its breeding grounds in the Arctic to its wintering grounds in Antarctica, covering a distance of 25,000 miles!

10. Hair Hair offers important protection from the elements (weather)
Musk Ox- Its thick, shaggy hair hangs down to the ground and gives the ox the protection it needs to endure frigid temperatures in the Alaskan tundra. (Winter temperatures= average of -30°F)
Sheds some hair in time for summer, to itself cool down as temperatures reach 40-50°F

11. Resource Conservation
Scarce/limited resources?
Ability to conserve fat & water in the body can mean the difference between life and death
EX: Bactrian camel, a two-humped ungulate that lives in the rocky and arid regions of Central and Eastern Asia, where temperatures range from -20°F in winter to 100°F in summer.
humps are filled with fat, which can be converted into energy and water
can forgo sweating until their body temperatures reach nearly 105°F.

12. Camel Adaptations Rap
Pay attention to the various ways camels are ADAPTED to their environment…

13. Natural Selection
There are several factors that Darwin identified that affect the process of natural selection:
Overproduction of offspring
Competition
Variations

14. Overproduction
- Most species produce far more offspring than can possibly survive

15. Competition
-Struggle between organisms for limited resources in a habitat (food, water, shelter, space)

16. Variation
- Any difference between individuals of the same species

17. Do species change over time?
Yes, The process in which populations gradually change over time is called evolution.

18. Ways Evolution Can Occur:
Punctuated Equilibrium: Species evolve very rapidly and then stay the same for long periods of time
Gradualism: Slow, constant change

19. Evolution vs. Natural Selection (minutephysics)

20. If time, watch Brain Pop videos on Natural Selection & Charles Darwin
Stop Here today!