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26/09/2016
Dr Dave Hone
BIO 113 Evolution
Dr David Hone
• Room 6.14 Fogg
Building
• [email protected]
• Research – the ecology
and behaviour of the
carnivorous dinosaurs
and the palaeobiology
of the pterosaurs.
• davehone.co.uk
Dr Beth Clare
• Room 5.03 Fogg
• [email protected]
• Research –
foodwebs, DNA
barcoding, especially
tropical bats.
• http://webspace.qm
ul.ac.uk/eclare/index.
html
• Week 1: DH – History of Evolutionary Thought, Darwin’s
ideas
• Week 2: DH – Geological Aspects, Drivers of Evolution,
Levels of Evolution
• Week 3: DH – Learning from fossils, learning from DNA
• Week 4: DH – Systematics, Speciation
• Week 5: DH – Evolution of Sex, Sexual Selection
• Week 6: EC - Genetic Basis of Evolution (x2)
• Week 6: NHM workshop (TBC)
• Week 7: Mid semester break, no lectures.
• Week 8: EC – Selection, Gene Flow, and Mutation
• Week 9: EC – Founder Effects, Inbreeding, and Hybrid Zones
• Week 10: EC – Evolution in Action (x2)
• Week 10: Computer workshop (TBC)
• Week 11: DH - Convergence, Evolution of Parasites
• Week 12: DH – Human Evolution, Revision Session
BIO 113
• 22 Lectures (Mondays 10 & 1)
• 2 Workshops (Weeks 6 & 10 - TBC)
• Official course text….none, but:
• You are expected to do extra reading.
• Use good sources.
Assessments
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Workshop 1 ‘fill in the blanks’ questions (10%).
Workshop 2 A short MCQ test (10%).
Exam section 1, MCQs (34%).
Exam section 2, short answer questions (choice of
2 – 33%).
• Exam section 3, EMQs (33%)
• ‘The criteria used in marking on the module have
been made clear in advance’
Definitely agree (5) Definitely disagree (1)
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In this module:
Any Questions?
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History of evolutionary theory
Basis of modern evolutionary theory
Speciation and diversity
Major patterns in evolution
Genetic basis of evolution
Evolution of man
In this lecture:
History of Evolutionary
Thought
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History of evolutionary ideas
Changing species?
Major concepts
Major contributors
Evolution as a theory
Who is this?
“Nothing in Biology
Makes Sense Except in
the Light of Evolution”
Theodosius Dobzhansky, 1973
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And what did he discover?
And what did he discover?
And how would you define it?
• Natural selection (not the same as evolution).
• It was already known (or at least suggested),
did however provide evidence, context and
support and popularised the concept.
• But first, winding back….
Fixed or changing?
• 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 Uniformitarianism: Changes in
nature are gradual.
• 1798, Cuvier: Fossils show extinct species (due
to catastrophe), but species don’t change.
Carolus Linnaeus (1707-1778)
• 180 books classified
nature: “revealing
the order of life
created by God.”
• “God created,
Linnaeus arranged”
• Thought species
were immutable
Three major concepts
• Each species
was created
separately.
Three major concepts
• Lamarck:
characteristics
are acquired
by an
individual and
are passed on
to offspring.
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J-B. de Lamarck (1744-1829)
• Lamarck:
acquired
characteristics
are passed to
offspring.
• E.g. stretching
giraffes
lengthened
their necks to
reach tree-top
vegetation.
• Worked most of his life
at the Muséum
d’Histoire Naturelle.
• Promoted the idea that
species change.
Beatrice the Biologist
Three major concepts
Thomas Malthus (1766-1834)
• Published on
“principle of
population”:
• Human populations
increase faster
(geometrically =
exponentially) than
food production
increases
(arithmetically =
linearly).
• Darwin (and
others): species
change over
time and
produce new
species.
Charles Lyell (1797-1875)
• Geologist, strong
proponent of
uniformitarianism
(slow gradual
change).
• Wrote the ‘Principles
of Geology’ (3 vols,
1830-33).
Uniformitarianism
• Four major ideas:
• Accepted by scientists now:
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.
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And so….
Darwin and the Beagle
• Enter a young failed medical student.
• 1831-1836
Charles Darwin (1809-1882)
Galápagos finches
• Darwin became famous as
a result of his published
books about the trip.
• He settled down and
began to think seriously
about his ideas and work
out what might explain the
diversity and patterns he
had seen.
Suggestion
• Finches derived from one ancestral species
arriving from the mainland to populate and
diversify across the islands (adaptive
radiation).
• Animals changed in response to differing
conditions / opportunities.
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The Origin
• The Origin of Species was
published in 1859.
• Darwin had sat on the
extended manuscript for
years but was prompted by
letters from Alfred Russel
Wallace.
Presented to the Linnean Society
Alfred Russel Wallace (1823-1913)
• Made a living from
collecting specimens
for collections.
• Was working in
Indonesia at the time
which made
communication
difficult.
Evolution by natural selection
• Under optimal conditions, populations indefinitely
increase in size.
• But this does not happen as:
not all animals reach maturity
some animals breed less
• Individuals within a population differ (natural variation)
• Some differences (traits) affect survival/reproduction
• Some of these traits are heritable: passed on from
parents to offspring
• Advantageous traits lead to increased relative survival
of certain lineages
Descent with modification
• Contrasts with the
other ideas.
• Now brilliantly
supported and
universally
accepted. Not so
at the time!
• (Not the only form
of evolution).
The Origin
• Lots of people had argued for changing
species and even why. Darwin however,
provided evidence!
• (Coming next)
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Darwin's theory of evolution by
natural selection
Modern Understanding
• OED:
Theory
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.
• 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 occurring independently on two
populations of a single species leads to the
accumulation of differences between the
populations - and ultimately to speciation.
Conclusions
Further Reading
• Ideas on how the diversity of life was/is
produced date back to the ancient Greeks
• These ideas developed considerably in the
1800s, with much initial disagreement,
culminating in the Theory of Evolution by
Natural Selection.
• http://evolution.berkeley.edu/evolibrary/articl
e/history_12
• http://www.aboutdarwin.com/voyage/voyage
01.html
• http://rationalwiki.org/wiki/Scientific_theory
• Remember these are starting points.
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