The document defines key objectives around evolution and biodiversity. It then provides examples of different mammalian species and groups them by common characteristics. The mechanisms of evolution are described as natural selection, mutation, genetic drift, gene flow and recombination. Charles Darwin's voyage on the Beagle is discussed, where he made observations that led to his theory of evolution by natural selection.

1. OBJECTIVES
 define evolution and biodiversity
 analyze the pattern of evolution
 illustrate the mechanisms of evolution

2. Mammalian species
diversity exercise

3. Monotremes
Short-beaked echidna - Platypus
Monotremes

4. Perissodactyls
Lowland tapir – Black rhinoceros
Odd-toed ungulates (Perissodactyls)

5. North African crested porcupine – American beaver
Rodents
rodents

6. African elephant - Rock hyrax
Afrotheria
afrotheria

7. Blue whale - Moose
Cetaceans + artiodactyls = Cetartiodactyls
Cetardiodactyls

8. Evolution and Origin of
Diversity

9. What is biodiversity?
• Biological diversity
• The simple version - number
of different species in a given
area or ‘species richness’
• BUT, it can also be diversity within species
(genetic diversity of alleles in a gene pool)
Coral reef

10. The Earth’s geological life may
simply be subdivided this way;

12. Why is there so much diversity?
• Overlaps - convergent evolution
Little goblin bat White-capped albatross

13. Why is there so much diversity?
→ EVOLUTION
• Evolution is the process by which change occurs in the heritable
characteristics (genes) of a population over successive generations
• Evolution results in diversity at every level (from
genes to species)
• This process happens naturally over a long period of time
• The result is a huge amount of diversity even between related
groups with a common ancestor

14. Charles Darwin

15. How do you think Darwin came
up with his theory?

16. Voyage of the Beagle

17. Voyage of Beagle
 Dates: February 12th, 1831
 Captain: Charles Darwin
 Ship: H.M.S. Beagle
 Destination: Voyage around the world.
 Findings: evidence to propose a
revolutionary hypothesis about how life
changes over time

19. Activity
 The students will be divided into five groups and
using the given materials they will illustrate the
concept on mechanism of evolution.

 Group 1. Natural selection
 Group 2. Mutation
 Group 3. Genetic drift
 Group 4. Gene flow
 Group 5. Recombination

20.  CRITERIA
 Correctness of answer
 50%
 Interpretation
 40%
 Visual appearance
 10%
 TOTAL
 100%

21. The Galapagos Island
 Darwin was fascinated in particular by the land
tortoises and marine iguanas in the Galápagos.
 Giant tortoises varied in predictable ways from
one island to another.
 The shape of a tortoise's shell could be used to
identify which island a particular tortoise
inhabited.

23. Darwin’s finches
Vegetarian finch
Large cactus finch
Medium ground finch Common cactus-finch

24. The Journey Home
 Darwin Observed that characteristics
of many plants and animals vary
greatly among the islands
 Hypothesis: Separate species may
have arose from an original ancestor

25. Basic Mechanism of Evolution

26. Natural Selection
 Natural variation—the process of
organisms with certain more favorable,
characteristics tending to reproduce more
successfully.
 differences among individuals of a species

27. Three Principles of Natural
Selection
 the characteristics of organisms are
inherited, or passed from parent to
offspring.

28.  Second, more offspring are produced than
are able to survive (resources for survival
and reproduction are limited).

29.  Third, offspring vary among each other in
regard to their characteristics and those
variations are inherited.

31. Types of Natural Selection

38. Mutation
 Mutation is the
ultimate source of
genetic variation in all
populations.

39. 3. Genetic Drift
 Genetic drift occurs because the alleles in
an offspring generation are a random
sample of the alleles in the parent
generation.

43. 4. Gene Flow
 Gene flow can occur when an individual
travels from one geographic location to
another and joins a different population of
the specie

46. Recombination
 - It occurs during meiosis when
chromosomes exchange genes. This process
ultimately leads to the formation of unique
gametes with chromosomes that are
different from those in parents.

47. Quiz
 How does natural selection can lead to
evolution?
 What is the relationship of mutation in
natural selection?
 How does genetic drift and gene flow affect
the diversity in organisms?

48. Assignment
 Study about Evolution and Origin of
Biodiversity: Patterns of Descent with
Modification

49. Evidence of Evolution
 The Fossil Record
 Geographic Distribution of Living Things
 Homologous Body Structures
 Similarities in Early Development

50. Evidence for Evolution
 The Fossil Record-
Layer show change
 Geographic
Distribution of Living
Things
 Homologous Body
Structures
 Similarities in Early
Development

51. Evidence of Evolution
 The Fossil Record
 Geographic
Distribution of
Living Things-similar
environments have
similar types of
organisms
 Homologous Body
Structures
 Similarities in Early
Development

52. Homologous Structures
 Homologous Structures-structures that
have different mature forms in different
organisms, but develop from the same
embryonic tissue

54. Evidence for Evolution
 Vestigial organs-organs that serve
no useful function in an organism
 i.e.) appendix, miniature legs, arms

56. Similarities in Early
Development

57. Summary of Darwin’s Theory
 Individuals in nature differ from one
another
 Organisms in nature produce more offspring
than can survive, and many of those who do
not survive do not reproduce.

58. Summary of Darwin’s Theory
 Because more organisms are produce than
can survive, each species must struggle for
resources
 Each organism is unique, each has
advantages and disadvantages in the
struggle for existence

59. Summary (cont.)
 Individuals best suited for the environment
survive and reproduce most successful
 Species change over time

60. Summary (cont.)
 Species alive today descended with modification
from species that lived in the past
 All organisms on earth are united into a single
family tree of life by common descent