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Biology 2900 Principles of Evolution and Systematics

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Title: Biology 2900 Principles of Evolution and Systematics


1
Biology 2900Principles of Evolutionand
Systematics
  • Dr. David Innes
  • Dr. Ted Miller
  • Jennifer Gosse
  • Valerie Power

2
Announcements
Sir Joseph Banks (1743-1820) Sir Joseph
Banks inherited his fathers estates in
Lincolnshire and considerable wealth in 1761. His
first voyage of discovery was to the coasts of
Newfoundland and Labrador on HMS Niger, and on
his return to London in 1767, he was elected a
member of the Royal Society at the age of just
23. Banks was involved in most British
voyages of discovery of his day, including the
Bounty voyage under William Bligh, 1787-1789,
Blighs later voyage in HMS Providence, and
Matthew Flinderss circumnavigation of Australia,
1800-1805. He also organised the introduction of
the first sheep into Australia.
Happy Birthday (Feb. 12, 1809)
Happy Birthday (Feb. 13, 1743)
Every blockhead does that My grand tour shall
be one round the whole globe (Joseph Banks in
response to his familys suggestion that he
undertake the traditional Grand Tour of Italy and
the sites of classical antiquity). And it
was. Joseph Banks (17431820), one of the richest
characters, most multi-talented and indefatigable
of 18th century individuals (later President of
the Royal Society for 41 years) joined Captain
Cook on HMS Endeavours first journey (1768).
When the voyage set out, Banks was only 25.
Samuel Johnson, remarked of the 106 foot
Endeavour that, rather than sail on her, he would
have turned, with relief, to jail.
Banksia
3
Announcements
  • Lab 3 (Group 1) handout ? print from course web
    page
  • http//www.mun.ca/biology/dinnes/B2900/B2900.html
  • Midterm Test Thursday Feb. 15

4
Announcements
  • Chapter References (Futuyma, 2004)
  • Ch. 1. Evolutionary Biology p. 1 14
  • Ch. 3. Patterns of Evolution Box 3A p. 48 49
  • Ch. 9 Variation p. 189 222
  • Ch. 10 Genetic Drift p. 225 235 241 242
  • Ch. 11 Natural Selection and Adaptation p. 247
    255
  • Ch. 12 The Genetical Theory of Natural Selection
    p. 269 285 293 294
  • Ch. 13 Evolution of Phenotypic Traits p. 297
    301 304 310 317 319
  • Ch. 17 How to be fit Reproductive Success p. p.
    417 - 422

Midterm Test Thursday Feb. 15
5
Announcements
Midterm Test Thursday Feb. 15
  • Format
  • A. True / False
  • B. Short Answer
  • C. Matching terms
  • D. Problem
  • Read and interpret graphs,
    draw graphs
  • Example Test
  • http//www.mun.ca/biology/dinnes/B2900/Midterm00.h
    tml

6
Principles of Evolution and Systematics
  • Darwin Natural selection (Galapagos Finches )
  • Population Quantitative genetics (Genes in
    populations)
  • Natural selection Adaptation (Form and
    function)
  • Adaptation and Diversity
  • (part I part II)

7
Studies in Evolution
  • Reproductive success
  • Sex and Sexual Selection

8
  • Reproduction
  • Reproduction an important adaptation
  • A diversity of modes of reproduction

9
Variation in Reproduction
  • Separate sexes - dioecious (plants)
  • - gonochoristic
    (animals)
  • Co-sexual hermaphroditic
  • (malefemale)
  • Asexual

10
Sexual Selection
  • Chapter 14

11
Sexual Dimorphism
  • Males and females often differ in size,
    appearance and behavior

?
?
Whats he on about ?
12
Male and female height dimorphism in 200 human
societies
In addition, Secondary sex characteristics
13
Adaptive significance of sexual dimorphism??
  • Sexual dimorphism difficult to
  • explain by natural selection
  • Example long tail feathers
  • How can the evolution of sexual dimorphism be
    explained?

14
Darwin and sexual dimorphism
  • Challenges for passing on ones genes
  • 1. Surviving
  • 2. Reproducing
  • And for sexual reproduction
  • 3. Finding and mating with
    a
  • member of the opposite
    sex

15
Sexual Selection
  • Differences among individuals at getting mates
  • i.e. Mating success

16
Sexual Selection
  • Asymmetry
  • - eggs are more expensive than ejaculates
  • (eggs yolky sperm DNA propeller)
  • - parental care by females, none by
  • males (90 of mammal species)

17
Sexual Selection
  • Asymmetry
  • Females
    Males
  • Limits to of eggs of
  • reproductive produced matings
  • success

Access to females a limiting resource for males
18
Batemans Experiment
  • Test of asymmetric reproductive success
  • D. melanogaster 3 virgin males
  • 3 virgin females
  • (each individual had 3 potential mates)
  • Measured
  • 1. number of actual mates
  • 2. reproductive success ( of
    offspring)

19
  • Results

(a)
(b)
(c)
Variance in reproductive success males gt females
20
  • Results

Males reproductive success increases with
number of mates great variation
in the number of mates great
variation among males in reproductive
success Females no increase in reproductive
success with gt 1 mate less
variation in number of mates
little variation among females in reproductive
success
Other examples ??
21
Rough-skinned newt
males
females
  • All females mated
  • Most males not mated
  • Females number of mates doesnt increase of
    offspring
  • Males increased of offspring with of mates

22
Consequences of asymmetry (Female parental care)
  • Males should be competitive (intrasexual
    selection)
  • Females should be choosy (intersexual
    selection)
  • Because females commonly invest much more
    per offspring than males

23
Sexual Selection
  • Male-Male Competition
  • 1. Combat
  • 2. Sperm competition
  • 3. Infanticide
  • 4. Alternative mating strategies
  • 5. Female Choice
  • 6. Run away sexual selection

24
  • Male-Male competition
  • (size matters)
  • 1. Combat
  • - favours larger body size
  • - weaponry
  • - armor

Which is the male?
25
Male Combat
(Marine Iguana)
Variation in mating success
observer
territories
Largest male
26
Male-Male competition
  • 2. Sperm competition
  • Male mating success not determined by
    copulation but, whether his sperm fertilizes eggs

27
Sperm Competition
  • Internal fertilization
  • If female mates
  • with 2 or more males,
  • sperm race to the eggs

28
Sperm Competition
M F offspring potential fathers
  • external fertilization
  • Internal fertilization
  • - polyandrous species
  • - socially monogamous
  • species (extra-pair
  • copulation)

29
Sperm Competition
  • Adaptations to increase chances of winning the
    sperm race
  • Large ejaculates with many sperm
  • prolong copulation
  • mate guarding
  • copulatory plug

30
Sperm Competition
  • Med. Fruit fly males
  • sperm
  • ejaculated
  • 1. Private mating 1,379
  • 2. With a potential 3,520
  • competitor

31
Mate Guarding
Male barn swallows
Eggs laid
Female fertile period
32
  • Sperm Competition
  • Other Adaptations
  • Damsel flies

Removes sperm from previous mating
33
Sperm Storage
  • Birds, insects, mammals
  • Control of sperm use by female
  • - Last male sperm precedence
  • - First male sperm precedence
  • - Mixing of sperm

34
Sperm Mixing(wood louse)
  • Female Progeny Genotype
  • 2/2 2/3 2/4 2/5
    2/6
  • 2/2 2 10 7 21
    1
  • Maternal allele 2
  • Paternal alleles 2, 3, 4, 5, 6
  • Possible male genotypes 2/3, 4/5, x/6
  • (sperm from at least 3 males)
  • 20 females gt 80 multiple
    paternity

35
An Evolutionary History of Sperm Competition T.
R. Birkhead (2000)
36
Sperm Competition
37
  • Male-Male competition
  • 3. Infanticide
  • Pride basic social group of lions
  • Newly mature males move to another pride
  • New male kills nursing cubs
  • - not his offspring
  • - causes females to return to breeding
    earlier

38
  • Male-Male competition
  • 4. Alternative mating strategy

Female
Sneaky males
39
  • 5. Female Choice
  • Males unable to monopolize females
  • Males advertise for mates
  • Females inspect and choose
  • sexual selection leads to elaborate
    courtship displays by males

40
  • Female Choice
  • Example
  • Barn Swallows
  • Males have longer tail feathers
  • Used in courtship display

males
females
41
  • Experiment
  • (Anders MØller)
  • Groups (males)
  • 1. Shortened tail feathers
  • 2. Control I (mock alteration)
  • 3. Control II (unaltered)
  • 4. Elongated tail feathers

42
  • Results

Premating period second clutches
of fledglings
Demonstrates females prefer males with longer
tails long-tailed males have high RS
43
Extra-pair copulation
  • Shortened Control
    Control Lengthened
  • tails I
    II tails
  • By their
  • female 0.036 0.014
    0.017 0.00
  • pair-mates
  • Females with the least desirable mate, had the
    highest rate of
  • extra-pair copulations

44
Extra-pair copulation
  • Paternity Analysis
  • DNA fingerprinting
  • Socially monogamous species (red-winged black
    birds) show extra-pair copulations
  • 50 64 of nests

45
  • Female Choice
  • Why should females be choosy ?
  • Male display an indicator of good genes
  • Male free of parasites
  • Acquisition of resources from males (gifts)
  • Preexisting sensory biases
  • Runaway sexual selection

46
  • 6. Runaway Sexual Selection
  • Example Stalk-eyed flies
  • Females preferred males
  • with long eyestalks
  • 2. Males with long eyestalks left
  • more offspring

47
  • Runaway Sexual Selection

3. Sons inherit long eyestalks, daughters a
preference for long eyestalks (assortative
mating) 4. Each generation males have longer
eyestalks and females prefer longer
eyestalks 5. Positive feedback loop
48
Sexual Selection in Plants
Wurmbea dioica
Dimorphic
male
female
49
Sexual Selection in Plants
  • Female invests more (seeds)
  • Access to pollinators limits mating success in
    males more than females
  • Increased flower size in males increases
    pollinator visits

50
Sexual Selection in Plants
  • Male-Male competition
  • - pollen tube growth
  • (sperm competition)
  • Female Choice
  • - manipulate pollen tube growth
  • - selective seed abortion

51
  • Sexual Selection

Summary 1. Differences among individuals at
getting mates 2. Asymmetry in limits to
reproductive success - females
of eggs - males of
matings 3. Male competition, female choice
52
  • Sexual Selection

Summary 4. Reversed when males invest more than
females ( male parental care pipe
fish) 5. Principles of sexual selection in
animals can be applied to flowering plants
53
  • Sexual Selection

Dr. Ian Jones (Biology) Sexual selection in
Auklets
Aethia pygmaea I. Jones
54
Principles of Evolution and Systematics
First Half Topics
  • Introduction (Thinking like an evolutionary
    biologist)
  • The evidence for evolution (Relatedness of life
    forms)
  • Darwin Natural selection (Galapagos Finches )
  • Population Quantitative genetics (Genes in
    populations)
  • Natural selection Adaptation (Sex and

  • Sexual
    selection)
  • Adaptation and Diversity

55
  • Coming Next
  • The History of Life
  • (in 12 lectures)
  • Narrated by Dr. Ted Miller
  • Thursday Feb. 22, 2007
  • Show times 1030 1145
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