2. 5/13/2014
Give an example of an organism that is well-adapted to its environment. Explain why it is well-adapted.

3. I can explain how species adapt and populations evolve.
Today’s Goal
I can explain how species adapt and populations evolve.

4. Today’s Plan
Natural Selection
Beak Lab

5. Natural Selection “Survival of the fittest”
Individuals that fit best with the environment survive and reproduce to pass on their “good” genes

6. Charles Darwin
Starting in 1831, spent nearly 5 years sailing around most of the world
Studied lots and lots of species
Published his findings in 1859 in the book On the Origin of Species

7. Darwin’s Main Points Every population has variations.
Some variations are better than others.
The offspring that survive have good traits.
Populations change over time.

8. Which worms are selected AGAINST?
There are 2 types of worms: worms that eat at night (nocturnal) and worms that eat during the day (diurnal). The birds eat during the day and seem to be eating ONLY the diurnal worms. The nocturnal worms are in their burrows during this time.
Which worms are selected AGAINST?
How does this population have variations?
Which variation is favorable?
Which worms will survive?
How will the population change over time?

9. Which bears are selected AGAINST?
There are 3 types of polar bears: ones with thick coats, ones with thin coats and ones with medium coats. It is fall, soon to be winter. The temperatures are dropping rapidly and the bears must be kept warm, or they will freeze to death.
Which bears are selected AGAINST?
How does this population have variations?
Which variation is favorable?
Which bears will survive?
How will the population change over time?

10. Which ostriches are selected AGAINST?
In ostriches, there are 2 types: ones that run fast and those that run slowly. The fast birds can reach up to 40 miles an hour. Jackals love to eat ostrich, and they can reach speeds of up to miles per hour.
Which ostriches are selected AGAINST?
How does this population have variations?
Which variation is favorable?
Which ostriches will survive?
How will the population change over time?

11. Which rabbits are selected AGAINST?
There are two types of rabbits: those that strictly eat grass and those that strictly eat berries and flowers. A drought occurs one year, and the plants have difficulty producing any extras (flowers, berries, etc.). They can only try and keep themselves green.
Which rabbits are selected AGAINST?
How does this population have variations?
Which variation is favorable?
Which rabbits will survive?
How will the population change over time?

12. Natural Selection