1. Evolution

2. Warm-up Essential Question What does evolution mean to you?
How does the gene pool change over time and why?

3. Evolution Notes
Evolution- change in the gene pool of an organism over time
Gene Pool- combined genetic information of all the members of a particular population

4. Biodiversity is the result of Evolution- Change Over Time within a POPULATION
Microevolution- evolution below the species level
Macroevolution- evolution which gives rise to new species

5. Mechanisms of Evolution
Mutations- random changes in the genetic code that may improve an organisms chance of survival and reproduction
Recombination- sexual reproduction in organisms require and exchange of chromosome pieces during meiosis leading to a new combination of genes.

6. Mechanisms of Evolution, continued
Artificial Selection- when humans determine which individuals breed.
EX: Food Crops (broccoli), antibiotics create resistant bacteria
Natural Selection- the environment determines which individuals are most likely to survive and reproduce.
Fitness- combination of traits that allow for survival => adaptations

8. Mechanisms of Evolution, continued
Genetic Drift- random mating affects genetic composition of a population
Large pop- remains the same
Small pop- some genotypes may be lost
EX: pop of 5 mice- 3 white mice breed but the 2 black mice do not=> black genes lost

9. Mechanisms of Evolution, continued
Bottleneck Effect- a population suddenly decreases in size.
Some genotypes will be lost and the new population’s genotype will be different from the original population

10. Mechanisms of Evolution, continued
Founder Effect – a few individuals from the mainland colonize an island
Some genotypes from the mainland will not be present on the new island

11. Species distributions
Range of tolerance- all species have an optimal environment in which it performs well. The limit to the abiotic conditions they can tolerate is known as the range of tolerance.

12. Species distributions, continued
Niche – the ecological ‘role’ of an organism based on:
how it meets its needs for food and shelter
how it reproduces
Generalist- species that live under a wide range of conditions- easily adapt
Specialist- species that live only in specific habitats- more likely to go extinct

14. The 5 fingers of evolution
Pinky: population decreases
Ring finger: non-random mate selection
Middle finger: mutations
Index finger: movement
Thumb : adaptation

15. Evolution- as genetic change
Ways that a species changes:
Directional selection
Stabilizing selection
Disruptive selection

16. Directional selection- fitness on one end of the curve is higher therefore shifting the curve in that direction

17. stabilizing selection- fitness in the middle of the curve is higher than the ends, therefore the curve narrows

18. disruptive selection- when fitness at the upper and lower end are higher than the middle, therefore the population splits

19. Evidence of Evolution
Fossils- preserved evidence of an ancient organisms
remains, impression, or other evidence

20. Evidence of Evolution
2. Geographic Distribution of living species

21. Evidence of Evolution
3. Homologous Body Structures- structures that have different mature forms in different organisms but are related structures.

22. Evidence of Evolution
4. vestigial- something that serves no useful function in an organism

23. Evidence of Evolution 5. We’ve seen it happen! Here’s some examples:
Hudson River Fish evolved to withstand toxins in the water
Peppered moths are darkening to blend in with soot-covered trees from pollution
3-Toed Skinks evolving to give
live birth instead of laying eggs

24. Grand canyon squirrel North and South rims
Elk/deer born darker after forest fire

25. Humans drive evolution too!
Bacteria becoming antibiotic resistant
Weeds and insects becoming resistant to herbicide/ pesticide
Cities create a new environment that some animals can better adapt to (ex: periguine falcons)