1. Evolution

2. Adaptations Variations are Differences in a species
Example: long necks on giraffes
Adaptation is
When an organism becomes better suited to its environment
Examples (give 3):
Body Structure/Function
Coloration
Behavior

3. Adaptations

4. Geological Time Evolution is
Change over a period of time and is based on present scientific data
Evidence of evolution is found in remains called
Fossils
Formation of fossils:
Imprint: formed from soft body parts
Molds or casts: a cavity in the shape of the organism
Petrified: hard parts replaced by minerals
Amber: Hardened sticky plant resin
(captures small organisms)

5. Geological Time Paleontologists They reasoned that the arctic was once
Look for and study fossils
They reasoned that the arctic was once
Warm and humid
(petrified forests)

6. Geological Time There are 3 eras: Paleozoic, Mesozoic, and Cenozoic
The timeline of life that scientists made by studying fossils is the
Fossil record
There are 3 eras: Paleozoic, Mesozoic, and Cenozoic
Each is broken down into periods. Then broken down into epochs.
Precambrian period lasted 4 billion years and there is evidence of
Bacteria and algae

7. Evidence for Evolution
Homologous organs or body parts are
Similar in structure
Examples: forelimbs of whales, human arm, Hox Genes

8. Evidence for Evolution
Analogous organs or body parts have
Same function but different structure
Examples: wing of fly vs. wing of bird

9. Evidence for Evolution
Human appendix provides evidence of
Evolution and the structure is called
Vestigial

10. Evidence for Evolution
Embryological evidence of vertebrates is similar in
The early stages

11. Evidence for Evolution
Biochemical evidence suggests that
Living things share many of the same amino acids
Molecular evidence suggests that the genetic code is nearly universal
Biochemical and molecular evidence are studying the same thing!

12. Theories of Evolution
Hutton and Lyell recognized that Earth is millions of years old, not thousands
Processes that changed Earth in the past are still happening today
These processes can explain how things can be built up or eroded away over millions of years

13. Theories of Evolution Example: giraffe long necks
Lamarck’s Theory: believed that traits acquired in one generation could be inherited by the next
Acquired = actions of the organism causes
Example: giraffe long necks

14. Theories of Evolution
Lamarck’s Theory

15. Theories of Evolution
Darwin’s Theory of Natural Selection: organisms that are best suited to their environment survive and reproduce
“survival of the fittest”

16. Theories of Evolution Darwin’s Theory based on 4 facts:
Overproduction:
To produce more offspring than could survive
Struggle for existence:
Competition for survival (food, water)

17. Theories of Evolution Darwin’s Theory based on 4 facts: Variations:
Differences
Natural selection & the Origin of New Species:
Helpful variations, some neutral

18. Theories of Evolution

19. Theories of Evolution DeVries claimed that new species arose
From “mutations”

20. Adaptive Shifts
Changes in the frequency or occurrence of certain genes as environment changes
Examples (give 2): peppered moth and black moth

21. Adaptive Shifts
Changes in the gene pool of a population may also be a result of migration, which is the movement of an organism into or out of a population

22. Adaptive Shifts
Isolation occurs when a population is separated from the other memebers of the same species
As a result it is possible for speciation to occur
Ex. Galapagos finches

23. Adaptive Shifts
Divergent Evolution is where many different species develop from a common ancestor
Ex: birds, whales, and bears
Common ancestor

24. Adaptive Shifts
Convergent Evolution is a process of unrelated species developing similar characteristics
Ex: whales & porpoises, dolphins & sharks
Unrelated species

25. Genetic Drift
A random change in allele frequency is called genetic drift
Bottleneck Effect:
Change in allele frequency following a dramatic reduction in the size of a population
Founders Effect:
Allele frequency changes due to the migration of a small subgroup of a population

26. Genetic Drift
Bottleneck Effect

27. Genetic Drift
Founders Effect

28. Genetic Equilibrium
Is when allele frequencies in a gene pool do not change for a population
Hardy-Weinberg principle:
Mathematically proves evolution
5 conditions that can disturb genetic equilibrium and cause evolution to occur:

29. 1. nonrandom mating: individuals select mates
sexual selection: genes for the selected for or against are not in equilibrium
2. small population size: evolution change due to genetic drift happens more easily in small population

30. 3. immigration/emigration: individuals coming into a population bring new alleles, while individuals leaving a population remove alleles from the gene pool

31. 4. mutations: can introduce new alleles into a gene pool
Changes allele frequencies
Causes evolution to occur
5. Natural Selection: genotypes that are better suited to an environment will disrupt genetic equilibrium causing evolution to happen.

32. Isolation Mechanisms: When some members of a population stop breeding with other members
Gene pool splits

33. Reproductive Isolation
Behavioral Isolation: differences in courtship rituals or other behaviors
Geographical Isolation: when 2 populations are separated by geographic barriers
Ex: rivers, mountains, bodies of water

34. Reproductive Isolation
Temporal Isolation: when two or more species reproduce at different times
Ex: flowers blooming

35. ***Darwin’s Finches & Speciation***
Occurred by:
Founding a new population, geographic isolation, changes in the new population’s gene pool, behavioral isolation, and ecological competition.
You Better KNOW This!!!!

36. ***Darwin’s Finches & Speciation***

37. ***Darwin’s Finches & Speciation***

38. Rate of Evolution p
Evidence shows: evolution occurs at different rates for different organisms at different times
Gradualism: slow and steady evolution

39. Rate of Evolution p
Punctuated Equilibrium: equilibrium interrupted by brief periods of more rapid change

40. Two Types of macroevoluation
Adaptive Radiation: evolution over short time into different forms that live in different ways
Modern Examples: Galapagos finches
Finches evolved different beaks & behaviors to enable them to eat different kinds of food

41. Two Types of macroevoluation

42. Coevolution
Coevolution: when two species evolve in response to changes in each other over time
Examples: flowers/pollinators