1. 1 Evolution Intro Diversity of Life

2. 2 “Nothing in biology makes sense EXCEPT in the light of evolution.” Theodosius Dobzhansky Evolution Charles Darwin in later years

3. 3 The Struggle for Existence

4. 4 Definition Evolution is the slow, gradual change in a population of organisms over time

5. 5 Voyage of the Beagle During His Travels, Darwin Made Numerous Observations And Collected Evidence That Led Him To Propose A Revolutionary Hypothesis About The Way Life Changes Over Time

6. 6 Darwin’s Observations Patterns of Diversity were shown Patterns of Diversity were shown Unique Adaptations in organisms Unique Adaptations in organisms Species Not Evenly Distributed Species Not Evenly Distributed »Australia, Kangaroos, but No Rabbits »S. America, Llamas

7. 7 Darwin’s Observations Both Living Organisms & Fossils collected Both Living Organisms & Fossils collected Fossils included: Fossils included: »Trilobites »Giant Ground Sloth of South America This species NO longer existed. What had happened to them?

8. 8 Evidence for Evolution – The Fossil Record

9. 9 Darwin’s Observations Left unchecked, the number of organisms of each species will increase exponentially, generation to generation In nature, populations tend to remain stable in size Environmental resources are limited

10. 10 Darwin’s Conclusion Production of more individuals than can be supported by the environment leads to a struggle for existence among individuals Only a fraction of offspring survive each generation Survival of the Fittest

11. 11 Darwin’s Observations Individuals of a population vary extensively in their characteristics with no two individuals being exactly alike. Much of this variation between individuals is heritable.

12. 12 Darwin’s Conclusion Individuals who inherit characteristics most fit for their environment are likely to leave more offspring than less fit individuals Called Natural Selection

13. 13 The unequal ability of individuals to survive and reproduce leads to a gradual change in a population, with favorable characteristics accumulating over generations (natural selection)The unequal ability of individuals to survive and reproduce leads to a gradual change in a population, with favorable characteristics accumulating over generations (natural selection) New species evolveNew species evolve Darwin’s Theory of Evolution

14. 14 The Struggle for Existence Each Species Struggles For: –Food –Living Space –Mates

15. 15 Population Growth Plants & Animals Produce Far More Offspring Than Can Be Supported –Most Die –If They Didn’t – Earth Would Be Overrun

16. 16 Darwin’s Theory of Evolution Populations and genetics Change Over Time

17. 17 Common Descent with Modification Darwin proposed that organisms descended from common ancestors Darwin proposed that organisms descended from common ancestors Idea that organisms change with time, diverging from a common form Idea that organisms change with time, diverging from a common form Caused evolution of new species Caused evolution of new species

18. 18. Natural Selection Driving force for evolution Driving force for evolution During the struggle for resources, best adapted survive & reproduce During the struggle for resources, best adapted survive & reproduce Idea that at least some of the differences between individuals, which impact their survival and fertility, are heritable Idea that at least some of the differences between individuals, which impact their survival and fertility, are heritable

19. 19 Darwin’s Notebook Project We will be taking a “Magic School Bus Ride” around the world looking at the vast variety of life on earth just like Darwin’s voyage via “Planet Earth” and “Life” videos while ISATS are going on. We will be taking a “Magic School Bus Ride” around the world looking at the vast variety of life on earth just like Darwin’s voyage via “Planet Earth” and “Life” videos while ISATS are going on. What is required? What is required? -List 25-50 different organisms -1-2 different adaptations the organism possesses that help it survive it’s environ. -An explanation of how each adaptation helps it survive it’s environment… 1-2 sentences. 1pt for each adaptation listed, 2 pt for each correct explanation= 100 total pts. THERE ARE NO EXCUSES ACCEPTED FOR NON- COMPLETION…even ISATS!!!!!!!!!!!!!! THERE ARE NO EXCUSES ACCEPTED FOR NON- COMPLETION…even ISATS!!!!!!!!!!!!!!

20. 20 A reconstruction of the HMS Beagle sailing off Patagonia. Darwin’s Voyage of Discovery

21. 21 HMS Beagle’s Voyage