1. Evolution

2. Evolution- change in population over time

3. Evolution- Darwin Darwin father of modern evolutionary theory
Galapagos Islands
HMS Beagle

4. Darwin HMS Beagle
Trip around the world

5. Scientists who influenced Darwin
Lamarck- organisms change due to the pressures of their environment, traits are acquired
He proposed that by using or not using its body parts, an individual tends to develop certain characteristics, which it passes on to its offspring.

6. Scientists who influenced Darwin- Lamarck
Example:
A giraffe acquired its long neck because its ancestor stretched higher and higher into the trees to reach leaves, and that the animal’s increasingly lengthened neck was passed on to its offspring.

7. Natural Selection
Natural Selection- organisms with traits best suited to the environment survive
have more offspring

8. Natural Selection
Example: Peppered Moths during the Industrial Revolution

9. Natural Selection Extinction- permanent loss of a species
5 mass extinctions
throughout history

10. Evidence for Evolution
1. Fossils
2. Comparative anatomy
3. Comparative embryology
4. Biochemistry
5. Genetic evidence
6. Direct evidence

11. Evidence for Evolution
1. Fossils
mold or cast
of organism left
in rock, fossilized bone and teeth
life becomes more complex over time
record is incomplete

12. Evidence for Evolution
Most complete
fossil record is
for the horse

13. Evidence for Evolution
Relative dating-
layers in rock bed used to date organisms
Deeper is older, shallow is younger

14. Evidence for Evolution
Radioisotope dating- uses half-life of element to estimate age of organism
Carbon is
used
frequently

15. Evidence for Evolution
phylogeny description of the lines of descent of plants and animals as they lived from one to the next
(how they are related)

16. Evidence for Evolution
2.  Comparative Anatomy- the study of the
structures of different organisms
homologous parts modified structures among different groups of descendants

17. Evidence for Evolution Comparative Anatomy

18. Evidence for Evolution Comparative Anatomy
analogous parts- structures in organisms that have no common origin but serve the same function
Example: bird’s wing, bat’s wing and insect’s wing

19. Evidence for Evolution Comparative Anatomy
vestigial organs- organs having no functions in the living organism
Vestigial toes in the horse
Vestigial pelvis and femur in whales

20. Evidence for Evolution
3. Comparative Embryology
the study of developing plants and animals
Below is the pictures of embryos for a fish, human, rabbit, tortoise, and chicken. Can you guess which one is each type of organism?

21. Evidence for Evolution
Comparative Embryology
Here the pictures of the second set of development is added. Can you tell now?

22. Evidence for Evolution
How about now?

23. Evidence for Evolution Comparative Embryology- The complete picture

24. Evidence for Evolution
4. Biochemistry
comparison of DNA and proteins in the body
Example: comparison of hemoglobin (blood protein) in human, chimp, and dog. Human and chimp hemoglobin more alike than dog

25. Evidence for Evolution
The closer related the fewer differences in DNA and proteins

26. Evidence for Evolution
5. Genetic Evidence
Mutations- mistakes in the genetic code
Causes changes in populations over time

27. Evidence for Evolution
6. Direct Evidence
Rapid Evolution
Strains of bacteria becoming resistant to antibiotics
Weeds and pesticides
Insects and pesticide

28. Adaptations
Adaptation- change in a species that makes it better suited to its environment
A hump to store nutrition during long trips or when food or water is scarce
Fur inside the ears to protect inner ear from sand
Long eyelashes to protect their eyes from the sand when the wind is blowing
Nostrils that close to keep sand out
Calluses on the the knees to protect from abrasion
Large feet for standing in the sand

29. Types of Adaptations Structural Changes in structure or anatomy
Example: bird’s beak or claws
Mimicry- a harmless species resembles a harmful one, predators learn to avoid both species
Camouflage- species features blend in with the environment

30. Mimicry

31. Camouflage
                                                                                                                                                

32. Types of Adaptations Physiological Changes in chemical makeup
Examples: digestion enzymes, snake venom, octopus ink

33. Types of Adaptations Behavioral Responses to the environment
Example: bird migration

34. Mechanisms for Evolution
Species- group of organisms that can interbreed AND produce viable offspring
Populations evolve NOT individuals

35. Origin of a Species Common Misperception: Individuals Evolve
Species evolve
NOT individuals
“And now there go the Wilsons!... Seems
Like everyone’s evolving except us!”

36. Mechanisms for Evolution
Gene pool- all the alleles for a trait in the population
Over time gene pools shift to traits that are best suited to the environment
Allelic frequency- the percent of any specific gene in a population
Genetic Equilibrium- when the percentage of alleles in a population remains stable over time

37. Natural Selection acts on variation in a population
1. stabilizing – favors average individual
2. directional – favors one extreme variation
3. disruptive – favors both extremes of variation

38. Natural Selection acts on variation in a population

39. Origin of Life on Earth
Spontaneous generation- non-living materials can produce life, life could be created out of nothing, from the air

40. Disproving Spontaneous Generation

41. Origin of Life
Biogenesis- living organisms only come from other living organisms

42. Origin of Cells Earth approximately 4.6 billion years old
Beginning- earth’s atmosphere Hot, gases like CO2 and nitrogen, little O2
Gases helped to create the atmosphere

43. Origin of Cells 3.5 to 4 billion years ago Organic Molecules 
Protocells 
Prokaryotic cells (heterotrophs) 
First simple autotrophs/producer 
Eukaryotic cells 
Multicellular organisms

45. Origin of a Species
Speciation – formation of a new species, members of similar populations no longer interbreed

46. Origin of a Species Geographic Isolation
Physical barrier divides population
River, canyon, mtn. splits group
Two species of squirrel split by the Grand Canyon

47.   Patterns in Evolution
Adaptive radiation – one ancestral species evolves into a number of species to exploit a number of habitats.

48. Patterns in Evolution
Divergent evolution- one species evolves into two species with different characteristics (get more and more different from each other)

49. Patterns in Evolution
Convergent evolution – distant or unrelated species evolve similar characteristics to take advantage of similar environments Example: fish and dolphin