January 2013 @ Queen Mary Uni London © Yannick Wurm & Chris Faulkes

1. SBS 110 - Evolution

2. SBS 110 - Evolution
“Nothing in Biology Makes Sense
Except in the Light of Evolution”
Theodosius Dobzhansky 1973

3. Course Outline
and Timetable

7. Recommended Reading

9. Paperback 352 pages
(2010)
Publisher: Profile Books
Amazon price: £5.89

10. Paperback 416 pages
(Jan. 1, 2007)
Publisher: McGraw-Hill
Education (ISE Editions)
Amazon Price: £25.73

11. Paperback 596 pages
(11 Aug 2005)
Publisher: Oxford University Press
Amazon price: £26.99

12. Lecture 1: Introduction and some
historical perspectives
1809—1882

13. Early ideas
Fixity of species or change?

14. Early ideas
Fixity of species or change?
350 B.C. Aristotle:
individuals in a “Species” are identical and unchanging

15. Early ideas
Fixity of species or change?
350 B.C. Aristotle:
individuals in a “Species” are identical and unchanging
1749 Buffon Histoire Naturelle encyclopedia:
The earth is very old. Species change.

16. Early ideas
Fixity of species or change?
350 B.C. Aristotle:
individuals in a “Species” are identical and unchanging
1749 Buffon Histoire Naturelle encyclopedia:
The earth is very old. Species change.
1785 Hutton. Geologist:
Uniformitarianism: Changes in nature are gradual.

17. Early ideas
Fixity of species or change?
350 B.C. Aristotle:
individuals in a “Species” are identical and unchanging
1749 Buffon Histoire Naturelle encyclopedia:
The earth is very old. Species change.
1785 Hutton. Geologist:
Uniformitarianism: Changes in nature are gradual.
1798 Cuvier:
Fossils show extinct species (due to catastrophe).
Species don’t change.

18. 3 Schools of evolutionary thought
1. Linnaeus:1700s
2. Lamarck: 1744—1829
3. Darwin & Wallace: 1800s

19. Carolus Linnaeus (1707—1778)
• Swedish
• 180 books classified nature:
“revealing the order of life created
by God.”
• Devised the binomial naming
system: Genus species
• Thought that species do not
change.

20. 3 Schools of evolutionary thought

21. 3 Schools of evolutionary thought
• Linneaus: each species was
separately created.

22. J-B. de Lamarck (1744—1829)
• Worked most of his life at the Muséum d’Histoire Naturelle (Paris)
• He promoted the idea that species change.

23. 3 Schools of evolutionary thought
1. Linnaeus:1700s
2. Lamarck: 1744-1829
3. Darwin & Wallace: 1800s

24. 3 Schools of evolutionary thought
• Linneaus: each species was
separately created.

25. 3 Schools of evolutionary thought
• Linneaus: each species was
separately created.
• Lamarck: characteristics acquired by an
individual are passed on to offspring.

26. Giraffe necks
• Lamarck: stretching giraffes
lengthened their necks to
reach tree-top vegetation.
This acquired characteristic
is passed to offspring.
• Darwin & Wallace: giraffes
with long necks out-
compete those with short
necks.

27. 3 Schools of evolutionary thought
1. Linnaeus:1700s
2. Lamarck: 1744—1829
3. Darwin & Wallace: 1800s

28. Thomas Malthus (1766-1834)
Published on Human population growth:
Human populations increase faster
(geometrically)
than food production (increases
arithmetically)
Ideas strongly influenced Darwin & Wallace

29. Charles Lyell (1797-1875)
A geologist and strong proponent
of uniformitarianism.
Ideas influenced Darwin and Wallace

30. Charles Lyell (1797-1875)
A geologist and strong proponent
of uniformitarianism.
Ideas influenced Darwin and Wallace
Uniformitarianism. 4 ideas:

31. Charles Lyell (1797-1875)
A geologist and strong proponent
of uniformitarianism.
Ideas influenced Darwin and Wallace
Uniformitarianism. 4 ideas:
• Accepted by all scientists:

32. Charles Lyell (1797-1875)
A geologist and strong proponent
of uniformitarianism.
Ideas influenced Darwin and Wallace
Uniformitarianism. 4 ideas:
• Accepted by all scientists:
1. Natural laws are constant across space and time

33. Charles Lyell (1797-1875)
A geologist and strong proponent
of uniformitarianism.
Ideas influenced Darwin and Wallace
Uniformitarianism. 4 ideas:
• Accepted by all scientists:
1. Natural laws are constant across space and time
2. Principle of parsimony: try to explain the past by
causes now in operation without inventing extra, fancy, or
unknown causes, however plausible in logic, if available
processes suffice.

34. Charles Lyell (1797-1875)
A geologist and strong proponent
of uniformitarianism.
Ideas influenced Darwin and Wallace
Uniformitarianism. 4 ideas:
• Accepted by all scientists:
1. Natural laws are constant across space and time
2. Principle of parsimony: try to explain the past by
causes now in operation without inventing extra, fancy, or
unknown causes, however plausible in logic, if available
processes suffice.
• Debatable:

35. Charles Lyell (1797-1875)
A geologist and strong proponent
of uniformitarianism.
Ideas influenced Darwin and Wallace
Uniformitarianism. 4 ideas:
• Accepted by all scientists:
1. Natural laws are constant across space and time
2. Principle of parsimony: try to explain the past by
causes now in operation without inventing extra, fancy, or
unknown causes, however plausible in logic, if available
processes suffice.
• Debatable:
3. Change is slow, steady, and gradual.

36. Charles Lyell (1797-1875)
A geologist and strong proponent
of uniformitarianism.
Ideas influenced Darwin and Wallace
Uniformitarianism. 4 ideas:
• Accepted by all scientists:
1. Natural laws are constant across space and time
2. Principle of parsimony: try to explain the past by
causes now in operation without inventing extra, fancy, or
unknown causes, however plausible in logic, if available
processes suffice.
• Debatable:
3. Change is slow, steady, and gradual.
4. Change is evenly distributed throughout space and time.

37. Darwin & the Voyage of the Beagle
1831-1836

38. Galápagos finches
• Analysis of these finches led to the hypothesis that they were derived
from one ancestral species arriving from the mainland to populate
and diversify across the islands (adaptive radiation).

39. Darwin
1837

40. Charles Darwin (1809-1882)
• Darwin at about 30 years old, and
three years back from his voyage
aboard HMS Beagle.
• The Origin of Species was
published several decades later in
1859 (prompted by competition
from Alfred Russel Wallace).

41. Alfred Russel Wallace (1823-1913)
• Wallace in his thirties. (National
Portrait Gallery, London.)
• In 1858 he came up with similar
ideas to Darwin about the
mechanism of evolutionary change

42. Read at the Linnean Society

43. Evolution by natural selection

44. Evolution by natural selection
Under optimal conditions, populations indefinitely increase in size.

45. Evolution by natural selection
Under optimal conditions, populations indefinitely increase in size.
Because they do not:
* either not all animals reach maturity
* and/or some animals breed less

46. Evolution by natural selection
Under optimal conditions, populations indefinitely increase in size.
Because they do not:
* either not all animals reach maturity
* and/or some animals breed less
Individuals within a population differ (natural variation)

47. Evolution by natural selection
Under optimal conditions, populations indefinitely increase in size.
Because they do not:
* either not all animals reach maturity
* and/or some animals breed less
Individuals within a population differ (natural variation)
These differences (traits) may affect survival/reproduction

48. Evolution by natural selection
Under optimal conditions, populations indefinitely increase in size.
Because they do not:
* either not all animals reach maturity
* and/or some animals breed less
Individuals within a population differ (natural variation)
These differences (traits) may affect survival/reproduction
Traits are heritable: passed on from parents to offspring

49. Evolution by natural selection
Under optimal conditions, populations indefinitely increase in size.
Because they do not:
* either not all animals reach maturity
* and/or some animals breed less
Individuals within a population differ (natural variation)
These differences (traits) may affect survival/reproduction
Traits are heritable: passed on from parents to offspring
Advantageous traits lead to increased survival of certain lineages

50. 3 Schools of evolutionary thought
• Linneaus: each species was
separately created.
• Lamarck: characteristics acquired by an
individual are passed on to offspring.

51. 3 Schools of evolutionary thought
• Linneaus: each species was
separately created.
• Lamarck: characteristics acquired by an
individual are passed on to offspring.
• Darwin & Wallace: viewed evolution
as descent with modification.

52. Giraffe necks
• Lamarck: stretching giraffes
lengthened their necks to
reach tree-top vegetation.
This acquired characteristic
is passed to offspring.
• Darwin & Wallace: giraffes
with long necks out-
compete those with short
necks.

53. Giraffe necks
• Lamarck: stretching giraffes
lengthened their necks to
reach tree-top vegetation.
This acquired characteristic
is passed to offspring.
• Darwin & Wallace: giraffes
with long necks out-
compete those with short
necks.

54. (1859) "The Origin of Species"

55. Darwin's theory of evolution by natural selection
theory |ˈTHēərē, ˈTHi(ə)rē|
noun ( pl. theories )
A scheme or system of ideas or statements held as an
explanation or account of a group of facts or phenomena;
a hypothesis that has been confirmed or established by
observation and experiment, and is propounded or
accepted as accounting for the known facts.
(Oxford English Dictionary)

56. Darwin's Theory of Evolution (1859)
"The Origin of Species"

57. Darwin's Theory of Evolution (1859)
"The Origin of Species"
• There is inherited variation within species.

58. Darwin's Theory of Evolution (1859)
"The Origin of Species"
• There is inherited variation within species.
• There is competition for survival within species.

59. Darwin's Theory of Evolution (1859)
"The Origin of Species"
• There is inherited variation within species.
• There is competition for survival within species.
• Natural selection is the process whereby genetically inherited
characteristics become more or less common in a population as a
function of the differential reproductive success of the bearers of these
characteristics.

60. Darwin's Theory of Evolution (1859)
"The Origin of Species"
• There is inherited variation within species.
• There is competition for survival within species.
• Natural selection is the process whereby genetically inherited
characteristics become more or less common in a population as a
function of the differential reproductive success of the bearers of these
characteristics.
•This process occuruing independently on two populations of a single
species leads to the accumulation of differences between the populations
- and ultimately to speciation.

61. Natural selection leads to
adaptive change
• But environmental conditions change:
What was advantageous yesterday may be a disadvantage today.
• And evolution also occurs by:
• genetic drift
• sexual selection
• artifical selection (selective breeding)

62. Summary of Lecture 1
Ideas on how the diversity of life was/is produced date back
to the ancient Greeks
These ideas developed considerably in the 1800s,
culminating in the Theory of Evolution by Natural Selection

64. Lecture 2
Darwin’s evidence for evolution
and
“Neo-Darwinism” or “The Modern Synthesis”

65. Darwin’s evidence for evolution

66. Darwin’s evidence for evolution
1. The Fossil Record

67. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy

68. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy
3. Comparative Embryology

69. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy
3. Comparative Embryology
4. Vestigial Structures

70. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy
3. Comparative Embryology
4. Vestigial Structures
5. Domestication (artificial selection)

71. 1. The Fossil Record: Paleontology
Random
order Reality: there is
sequential order to
the fossil record
Lecture 5

72. 1. The Fossil Record: Paleontology
Random
order Reality: there is
sequential order to
the fossil record
Lecture 5

73. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy
3. Comparative Embryology
4. Vestigial Structures
5. Domestication (artificial selection)

74. 2. Comparative anatomy
• Correspondence between parts and comparison of forelimbs among
four vertebrates.

75. Diversity of type, unity of pattern
• Although these vertebrate species
differ, the underlying pattern of the
forelimb is fundamentally the same.

76. Homology and analogy
• Homology - vertebrate forearms: the bat wing, mouse forearm, and
human arm are homologous structures as all are composed of similar
bones inherited from a recent common ancestor.

77. Homology and analogy
• Analogy: The wings of bats, butterflies, and birds evolved
independently, not from a recent common ancestor. But they
have a similar function, flight, and so are analogous.

78. Morphological series - evolution
of limbs from fins
• Note homology of structures

79. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy
3. Comparative Embryology
4. Vestigial Structures
5. Domestication (artificial selection)

80. 3. Comparative Embryology
• Embryonic retention of ancestral characteristics in vertebrates (e.g. gills
and tails)

81. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy
3. Comparative Embryology
4. Vestigial Structures
5. Domestication (artificial selection)

82. 4. Vestigial features I
• Whales: hips and hind limbs are reduced to small bones with no function.
• In primitive snakes, the remnants of hind limbs persist (forelimbs are
absent).

83. Vestigial features II
• The human appendix
is a vestigial
structure, reduced
from the caecum of
primate ancestors.

84. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy
3. Comparative Embryology
4. Vestigial Structures
5. Domestication (artificial selection)

85. 5. Domestication (artificial selection)
Von Holdt et al.
(2010) Nature
464, 898-903

88. Darwin’s evidence for evolution
1. The Fossil Record
2. Comparative Anatomy
3. Comparative Embryology
4. Vestigial Structures
5. Domestication (artificial selection)

89. Pattern and process in evolution
Inference Pattern
Inference
about
about
effect on
evolutionary
taxonomic
process
pattern
Process

90. Lecture 2
Darwin’s evidence for evolution
and
“Neo-Darwinism” or “The Modern Synthesis”

91. “Neo-Darwinism”
or
“The Modern Synthesis”

92. “Neo-Darwinism”
or
“The Modern Synthesis”
The same thing... but with better
understanding of how things work.

93. “Neo-Darwinism”
or
“The Modern Synthesis”
The same thing... but with better
understanding of how things work.
• Darwin’s Theory of Evolution by Natural Selection

94. “Neo-Darwinism”
or
“The Modern Synthesis”
The same thing... but with better
understanding of how things work.
• Darwin’s Theory of Evolution by Natural Selection
• Mendel’s Laws of Heredity (1866, 1900; see SBS 008)

95. “Neo-Darwinism”
or
“The Modern Synthesis”
The same thing... but with better
understanding of how things work.
• Darwin’s Theory of Evolution by Natural Selection
• Mendel’s Laws of Heredity (1866, 1900; see SBS 008)
• Cytogenetics (1902, 1904 - )

96. “Neo-Darwinism”
or
“The Modern Synthesis”
The same thing... but with better
understanding of how things work.
• Darwin’s Theory of Evolution by Natural Selection
• Mendel’s Laws of Heredity (1866, 1900; see SBS 008)
• Cytogenetics (1902, 1904 - )
• Population Genetics (1908; see Lectures 7-12)

97. “Neo-Darwinism”
or
“The Modern Synthesis”
The same thing... but with better
understanding of how things work.
• Darwin’s Theory of Evolution by Natural Selection
• Mendel’s Laws of Heredity (1866, 1900; see SBS 008)
• Cytogenetics (1902, 1904 - )
• Population Genetics (1908; see Lectures 7-12)
• Molecular genetics (1970s- ; see SBS 633/210 and Lecture 6)

98. Gregor Mendel (1822-1984)
Worked out the basic
laws of inheritance:
Segregation and
independent assortment

99. J.B.S. Haldane (1892-1964)
With Fisher and Wright, one
of the founders of population
genetics.
“The Causes of Evolution” (1932): first major contribution
to what became the “modern evolutionary synthesis".

100. R.A. Fisher (1890-1962)
Invented Analysis of Variance
and other stats!
Worked on the theory of
population genetics

101. Theodosius Dobzhansky
(1900-1975)
“Nothing in Biology makes
sense except in the light of
evolution”.
Theodosius Dobzhansky's
Genetics and the Origin of
Species, published in 1937.

102. Ernst Mayr (1904-2005)
Worked on speciation and
the definition of species.

103. Ernst Mayr (1904-2005)
Worked on speciation and
the definition of species.

104. Ernst Mayr (1904-2005)
Worked on speciation and
the definition of species.

105. William D. Hamilton (1936 - 2000)
Explained weird sex ratios
Explained how natural selection
acts on social behaviour (“kin
selection”)
relatedness * benefit > cost

106. John Maynard-Smith (1920-2004)
Most widely known for
applying game theory
to evolutionary biology

108. Summary/overview of Lecture 2
EVOLUTION
(“descent with modification”)
Pattern Process
• Fossil record • Mechanisms
• Dating methods • Environmental drivers
•climate
• Molecular evolution •cont. drift
• Molecular clocks •extinctions etc
The Modern Synthesis

109. What next?
• Epigenetics
• Cultural transmission “Extended Evolutionary Synthesis” ?
• Niche construction
• Comparative genomics
“Postmodern Synthesis” ?
• Systems Biology

112. Pastafarianism - Church of the
Flying Spaghetti Monster