1. Theory of Evolution
Stated Clearly: “What is Evolution.”

2. Evolution: refers to the process by which species of organisms change over time or the process of biological change by which descendants come to differ from their ancestors

3. Carolus linnaeus
-Came up with a system to organize and name all of the different known types of organisms, or species
-Species: a group of organisms that can reproduce and have fertile offspring
-Grouped organisms according to physical similarities & also showed evolutionary relationships

4. Theories of geologic change
Fossil: the remains or evidence of a once-living organism.
Theories of geologic change
Catastrophism: the idea that past natural disasters-like floods and volcanic eruptions- shaped landforms, and caused species to become extinct in the process
Gradualism: the idea that landforms were shaped by very slow changes over a long period of time, and not by natural disasters
Uniformitarianism: the idea that the same processes that shaped landforms in the past also shape landforms today

5. What did the Geologists Say?
Geology: the scientific study of Earth and its features
Charles Lyell: proposed uniformity - the idea that events in Earth’s past are similar to those happening now
Hutton and Lyell argued that the earth is many millions of years old because:
layers of rock take time to form
processes such as volcanoes and earthquakes shaped the earth and still occur today

6. Lamark Theory of acquired characteristics
Lamark said organisms acquired traits by using their bodies in new ways
These new characteristics were passed
to offspring
Proposed the principle of use and disuse
Lamark is well known for being WRONG .

7. Malthus
Reasoned that if the human population continued to grow unchecked, sooner or later there would be insufficient living space and food for everyone
*Remember it: MALTHus said there would be too many MOUTHS to feed.

8. Lots of other Sciences contributed to the theory of evolution
Anatomy
Embryology
Paleontology
Biochemistry
Molecular Biology
BUT MOST IMPORTANT WAS HEREDITY AND GENETICS!!!

9. Charles Darwin (1809-1882) Sailed around the world 1831-1836

10. What did Darwin’s Travels reveal?
The diversity of living species was far greater than anyone had previously known!!
He was amazed by the variation among similar species. Variation means the differences in the physical traits among individuals in a group of organisms.
These observations led him to develop the theory of evolution!!

11. How did tortoises and birds differ among the islands of the Galapagos?
-Each island had its own type of tortoises and birds that were clearly different from other islands.
-Why? Species were adapting to their environment. Adaptation is a feature that allows and organism to better survive in its environment.
-What did they have in common? Ancestry
-What was different? Ecosystem, beak shape (finches) and diet

12. Galapagos Turtles
Tortoises differed depending on where they lived. Dome-shaped shells and shorter necks lived on wet, highly vegetated islands. Tortoises with curved shells and long necks lived on drier islands.
Reproductive isolation: an inability of organisms to interbreed due to geographic barriers.

13. Evolution is a Theory – NOT a Law like Gravity!
Evolution is a well supported explanation of phenomena that have occurred in the natural world
A theory in science is a well tested hypothesis, not just a guess

14. Darwin finally published his ideas in 1859
Other naturalists were developing the same theory that Darwin did.
Darwin decided to publish even though he was afraid of the Church’s reaction to his book. He wanted to get credit for his work.

15. Natural Selection
The idea that organisms with favorable variations for their environment survive, reproduce, and pass those variations on to the next generation.