1. Anatomy & Physiology I - Unit 4: Evolution and Natural Selection

2. Tree of Life ~2000

3. Tree pattern suggests evolution
- the hierarchy of life is a family tree in which populations change with time.
- in general, similarities between species are due to relatedness.

4. Evidence for evolution
Fossils

5. Evidence for Evolution: Structural Similarities

6. Evidence for Evolution:
Developmental Similarities
Gill pouch
Tail
Figure: 21.2b
Caption:
(b) These photos show the strong resemblance of the early embryonic stages of a chick and a human.
Chick
Human
Homology: similarities caused by common descent

7. But how do species evolve?
Darwin figured out how.
It’s a process similar to how humans breed animals
Charles Darwin

8. Animal breeding aka “Artificial Selection”

9. How do you get this?

10. Evolution in action: Giraffe neck length

11. Happy Giraffes

12. Hungry Giraffes

13. Surviving Giraffes

14. With Evolution You Get: Taller giraffes over time

15. Evolution: A change in a population over time

16. Natural selection An environmental influence that gives some individuals in a population a reproductive or survival advantage over others. Principal cause of evolution.

17. Requirements for Evolution
Variability
Heritability
Differential survival or reproduction

18. Tall Giraffes
Mutation: random genetic changes

19. Speciation: separation by natural events that causes new species to develop

20. Discussion Question: Are humans still evolving?

21. Common Misperception:
Individuals
evolve
“And now there go the Wilsons!... Seems
Like everyone’s evolving except us!”

22. Acquired characteristics are not inherited! as in…..

23. Timmy & Gobbles

24. Evolution is slow Great Calendar
1 month 383 million years
1 day 13 million years
1 second 143 years
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Earth
forms
First
fossils
First
algae
First
land
plants

25. December 1 5 10 30 25 20 15
Land
animals
Dinosaurs
extinct

26. December 31 11:58:23 pm Native Americans reach Americas 11:48 pm
Modern humans
leave Africa
noon 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12
11:58:23 pm
Native
Americans
reach
Americas

27. Classroom Assignment: Building the Perfect Beast
- I want you to think about how the human body has evolved over time, and how it might have evolved better.
- Today you are in charge of the world, and you have to think about ways to make the human species better adapted to the environment.

28. Building the Perfect Beast
Pick any ten attributes or parts of the human body
Note the defect of that part, or how it might be made better
Describe your changes, piece by piece, oh master of the universe…
Draw me a picture of your perfect beast