Evolution??? Wha t is it?

1. Evolution??? What is it?

2. Evolution: A change over time in the genetic makeup of a population. Evolutionary adaptation: Accumulation of heritable traits that enhance the organisms ability to survive and reproduce in a specific environment. Natural Selection: change in a population over generations if individuals that have these traits leave more offspring than other individuals.

3. Timeline: Religious view of earth up until 1850's was that the earth was only a few thousand years old and that animal species were stagnant or not changing. (story of Noah) Carl Linnaeus (1770's) classified organisms forthe greater glory of God. He is father of modern Taxonomy and put organisms into groups based on similarities. Attributed these similarities to the fact that all organisms were created by one maker who had a master plan to work from. George Cuvier (early 1800's) saw fossils in separate layers that were different from those that existed in area. Explained findings as great catastrophes that killed the organisms there and others migrated in later from elsewhere.

4. James Hutton (Late 1700's) proposed that these changes occurred gradually (gradualism) and were normal, everyday occurrences. Valleys eroded by rivers and mountains pushed up over longer periods of time. Charles Lyell (early-mid-1800's) supported Hutton's idea and further stated that the occurrences of the past happened at the same rate as today (Law of uniformitarianism) Lamarck (early 1800's) first theory of evolution. His reasoning was flawed. He thought that organisms could acquire an adaptation in their lifetime and pass it on to their offspring. ex. giraffe would stretch its neck longer to reach higher leaves and pass this trait to its child. The child would then have an advantage over other giraffes and make this trait even better by stretching its neck even further.

5. Charles Darwin (mid-late 1800's) is the father of modern evolution. Began as a naturalist who was assigned to travel on the USS Beagle around the world to examine the plant and animal life.

6. Observations: That the plant and animal life found in the temperate regions of South America more resembled organisms from the tropical regions of South America rather than other temperate organisms from Europe. Fossils found in South America looked more like organisms in South America than any other region of the world. Saw the movement of the coastline move up two feet during an earthquake which suggested that mountains could be formed that way too over a much longer period of time.

7. Matched this up with the fact that there were oceanic fossils in the mountains (also reason behind the great flood stories of every religion) Other organisms on the island all resembled organisms from South America yet were very distinct and different from those same organisms. Finches observed on the Galapagos Islands looked very similar yet each species had adapted to different niches on the islands.

9. Hypothesis: Using Lyell's theory of gradualism, he believed the earth was much older than theologians believed and that organisms had plenty of time to adapt to their environments. The Galapagos were colonized by organisms from the mainland. Fossils found in the mountains were originally in the ocean and geological events pushed the land up. Believed that changes to the environment and the changes to organisms were closely related processes.

10. Alfred Wallace (mid- 1800's) presented his idea for evolution to Darwin before Darwin had published. Both presented the same idea to the scientific community but Darwin's proposal had much more supporting evidence than Wallace's. Darwin quickly finished his book "The origin of species and descent with natural selection". Wallace conceded that Darwin's explanation was much more detailed and Darwin is now known as the founder of evolution.