1. http://www. biologyjunction

2. Variation What is variation? Examples. How do we get variation?
Can everybody have the same types of variation? Explain.
Gene pool – set of genes available in a population

3. Jean Baptiste de Lamarck
Use and Disuse
Inheritance of Acquired Characteristics
Organisms acquire traits and pass these traits to offspring

6. Lamarck’s Influence Incorrect Not all traits acquired get passed on
Important
Introduced change over time
Realized organisms are changing

7. Charles Darwin Naturalist Traveled on the HMS Beagle (1831-1836)
South America, Galapagos Islands, Australia
Wrote The Origin of Species

9. Galapagos Islands Volcanic islands off the South American coast
no land mammals or amphibians
Island species varied from the mainland species, and from island-to-island
Each island had either long or short necked tortoises depending on the island’s vegetation

10. Finches
Finches on the Galapagos Islands resembled a mainland finch, but there were more types
Bill shapes are adaptations to different means of gathering food.
Galapagos finch species varied by nesting site, beak size, and eating habits

11. People influenced Darwin
Charles Lyell
Malthus
populations can grow exponentially
the are limited by war, disease, or resources
This led to Darwin’s idea that there’s a struggle for existence

12. Darwin’s Theory Humans can breed for certain traits
Dogs
Domestic plants
Could also happen in nature
Over time this could produce new species

13. Darwin’s Theory
adaptation - trait that helps an organism be more suited to its environment
adaptations develop over time
constant struggle for existence
Natural selection – organisms best suited for the environment reproduce more successfully
Survival of the fittest
Also proposed by Alfred Russell Wallace
Over several generations organisms with favorable traits increase

14. 1. Variation within a population
2. Variations are passed on

15. 3. More offspring are produced than can survive
4. Organisms that survive have favorable variations (adaptations)

16. Modification by Natural Selection
Fitness – genetic contribution to next generation
Environment “selects” traits
Favorable traits depend on demands of env’t
Reproduce more
Greater fitness
Better adapted

17. Summary of Darwin
Natural Selection – organisms best adapted to the environment survive and reproduce
the population is the unit of evolution
individuals do not evolve during their lifetimes
Conclusion on Finches
ancestral group of finches colonized islands
Absence of competitors allowed finches to gradually become specialized

18. What is natural selection?
Agenda for Friday May 27th
Finish notes
Breeding bunnies lab
Theories coloring

20. Cheetahs are able to run faster than 60 miles per hour when chasing prey. How would a biologist explain how the ability to run fast evolved in cheetahs, assuming their ancestors could run only 20 mph?

21. A long time ago, some cheetahs were faster than the others
The cheetahs that could run faster were able to catch their prey and were better able to survive
The slow cheetahs died off, or weren’t able to reproduce as successfully
The cheetahs that survived were the ones that could run faster

22. How does gene pool relate to variation?
Agenda for Wednesday May 21st
Finish theories notes

23. How did the heavy coat in polar bears evolve if their ancestors had thinner coats?
1. A long time ago, some polar bears had thicker fur than others
2. The thicker coat was favorable
3. The polar bears with thin coats died off.
4. The ones with thicker coats survived and reproduced.

24. Peppered Moths

25. Theory of Evolution
Evolution – change in the inherited traits of a population of organisms over time
NOT new species arising from pre-existing species