2. Did Darwin figured it all out by himself?… NO.
Each bar represents the life span of a scientist
that played a key role in the development of
modern evolutionary biology.

3. The First Person to Suggest Evolution was…
NOT Charles Darwin, but
Jean Baptiste Lamarck revived a theory that existed for thousands of years
Suggested species change over time and can become new species
BUT he had no evidence, and his hypothesis did not properly explain how evolution could occur

4. Charles Darwin
Proposed a well-thought out, coherent, well-researched hypothesis
Was scared to publish for many years.
Alfred Wallace published at the same time but Darwin’s version was more complete so he gets all the credit

5. Who was Charles Darwin? (1809-1882)
A. Failed as a doctor and a minister!
B – he becomes the naturalist aboard the H.M.S. Beagle for a 5 year mapping expedition to South America.
1. naturalist: includes collecting plant & animal specimens and documenting wildlife at all stops on journey.

6. Figure: 16-03
Title: Journey into History
Caption: The main mission of HMS Beagle’s 5-year voyage of 1831–1836 was to chart some of the commercially promising waters of South America. Charles Darwin served on board the ship as a resident naturalist and companion to ship’s captain Robert FitzRoy. Darwin observed nature and collected specimens throughout the ship’s journey, but for purposes of the theory of evolution, the ship’s most important stops came in 1835 on the Galapagos Islands, west of South America. The Beagle had a complex itinerary; for example, it stopped twice at the Falkland Islands off the southeast coast of South America, once in 1833 and again in 1834.

7. Ended up in…
4.)The Galapagos Islands – an island chain west of Ecuador.
a.) Each island has slight variations in climate as well as plant and animal life.

8. b.) Animals such as tortoises and birds called finches from different islands had slightly different body shapes and traits. Upon further study, Darwin and others determined that they were in fact different species!
i.) Species:
a group of similar organisms that can breed and produce viable offspring

9. c.) Darwin infers: an ancestral species of finch arrived on the islands from the mainland and spread from island to island. Each island species diverged over time into separate species based on the specific environment of each island.
Which leads to his hypothesis…

10. Lamark vs. Darwin
Before we do the notes you will explore the two different hypothesis to become more familiar with the differences

11. Jean – Baptiste Lamarck. In 1809, published a theory on evolution :
a.) Traits are developed out of “need”
b) Through use/disuse characteristics are developed.
c) An individual evolves in it’s lifetime & passes that trait to it’s children

12. A.) This is wrong! Why? Organisms cannot pass on acquired traits.
ex: A body builder does not have muscular babies
B) ALSO an individual does not evolve, a population evolves.

13. So… what did Darwin propose? 2 Main Parts
Natural Selection
Descent with Modification
Changes in the environment can cause populations to change over time…
this is the HOW evolution occurs
Species change over long periods of time
Enough differences accumulate that new species form
All species came from one common ancestor (this was a bit of a leap of faith on his part)

14. Evo Dots!
We will explore the “rules” of natural selection by running a computer simulation.

15. natural selection
There is a struggle for existence among organisms of same species (for food, space, mates, escape from predators) and only SOME individuals will survive long enough to reproduce.
A. “Rules” of natural selection
Population with variation
No variation…there will be no change!
individuals with favorable mutations causing favorable traits/phenotypes for that environment
We call these traits adaptations

16. a.) adaptations are: characteristics that increase an organism’s chance for survival.

17. Structural= a body part or coloring that aids survival
Bee orchid has both of these
Physiological= jobs of body parts controlling life processes that aids survival

18. Behavioral= an action that aids survival
Several types of frogs have learned to live in deserts. The come out of the ground during the rainstorms, breed quickly, feed a bit, and just as quickly re-burry themselves into mud and spit cocoons where they can live for several years! This guy’s name is The Catholic frog (Notaden bennetti)

19. Individual with a favorable trait (adaptation) for that environment tends to survive more often & reproduce
A) The ability of an organism to survive and reproduce in its environment is called its fitness.

20. a.) “Survival of the Fittest” - individuals that are best suited to their environment survive and reproduce.
a.) “Best suited” means that they have genotypes that produce phenotypes (adaptations) that help survive better.

21. 3. Because trait is in the genes the trait is heritable & passed to offspring A.) these individuals leave many offspring --b/c they are better suited to the env so they are healthier B) those with “unfavorable” traits/ phenotypes don’t leave as many offspring --b/c they are not as suited and thus not as healthy C) the population changes over generations towards the more favorable traits (adaptations) and more individuals have the favorable variation.

22. Remember: Natural Selection can only be observed as patterned changes in a population over many generations.
Evo/pbs