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Natural Selection, Evolution

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Title: Natural Selection, Evolution


1
Natural Selection, Evolution Implications for
the Conservation of Wildlife
2
Evolution
  • Its the process that drives-
  • the diversity of reproductive strategies weve
    studied
  • the ongoing relationships between predator and
    prey
  • the patterns of wildlife distributions around the
    globe
  • responses to disturbances
  • guides the migrants
  • as well as the demise of all the species that
    have become extinct throughout all of time

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  • Taxonomy Birds
  • Class Aves (birds)
  • Order Anseriformes (ducks, geese, swans, and
    relatives)
  • Order Galliformes (chicken-like birds)
  • Order Caprimulgiformes (nightbirds)
  • Order Apodiformes (hummingbirds and swifts)
  • Order Balaenicipitiformes (shoebill or
    whale-headed stork)
  • Order Charadriiformes (shorebirds and relatives)
  • Order Ciconiiformes (storks and relatives)
  • Order Coliiformes (mousebirds)
  • Order Columbiformes (doves and pigeons)
  • Order Coraciiformes (kingfishers and relatives)
  • Order Cuculiformes (cuckoos and relatives)
  • Order Falconiformes (diurnal birds of prey)
  • Order Galbuliformes
  • Order Gaviiformes (loons)
  • Order Gruiformes (coots, cranes, and rails)

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And even for humans, it drives
and who will not
who will survive
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And may just influence what happens next on
this graph
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  • Nothing in biology makes sense except in
    the light of evolution -Theodosius
    Dobzhansky
  • Evolution through natural selection
  • is the foundation of modern ecology,
  • biology and medicine.

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Theory or Fact?
  • In everyday vernacular, a theory is a guess.
  • As a scientific term, a theory is a statement of
    what are held to be the general laws, principles,
    or causes of something known or observed (OED)
  • A scientific theory is testable and can make
    verifiable predictions
  • In fact, it has been noted that we know more
    about the mechanisms of evolution than we do
    gravity, the nature of light, sleep, the weather,
    and something even more nebulous and stormy
    love.

9
  • Throughout much of human history, the dominant
    perspective (and still is in some of the less
    educated parts of the world and country), was
    that everything was divinely created in its
    present form, and that this Creator also
    orchestrated their interactions not unlike a
    master puppeteer.

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  • Theologist What have you learned about the
    mind of God in the course of your studies of
    biology?
  • J.B.S.Haldane Madame, only that he had an
    inordinate fondness for beetles.

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J.B.S. Haldane
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Charles Darwin(1809-1882)
  • Published one of the most
  • influential books ever written-
  • On the Origin of Species-
  • in 1859
  • 2009 marks the 200th anniversary
  • of his birth and 150th anniversary
  • of the publication of OtOoS

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The Galapagos Islands
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What is Natural Selection?
  • principle by which each slight variation of a
    trait, if useful, is preserved Darwin

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Natural Selection
  • Individuals within populations are variable for
    nearly all traits
  • Individuals pass on their genes to offspring
  • More offspring are produced than can survive
  • Individuals that survive and go on to reproduce
    (the most) are those with the varieties (alleles)
    that best adapt them to their environment
  • Outcome alleles associated with higher fitness
    increase in frequency from one generation to the
    next

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Artificial Selection
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Artificial Selection
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Natural Selection is also a part of population
regulation
  • The reproductive potential of populations is
    great, but
  • populations tend to remain constant in size,
    because
  • populations suffer high mortality.
  • Individuals vary within populations, leading to
  • differential survival of individuals.
  • Traits of individuals are inherited by their
    offspring.
  • The composition of the population changes by the
    elimination of unfit individuals
  • Rabbits should cover the earth, but
  • they dont, because
  • many are caught by predators.
  • Some rabbits run faster than others,
  • and escape from predators
  • and so do their young.
  • Populations of rabbits, as a whole, tend to run
    faster than their predecessors.

From Ricklefs The Economy of Nature Second
Edition
25
Important Points
  • Weak forces operating over long periods of time
    create large and dramatic change.
  • Natural selection is the non-random survival of
    random variants
  • Natural selection- by itself- is not evolution.
    It is the mechanism that can lead to evolution.
  • Natural selection takes place within a
    generation, but evolution takes place across
    generations.

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Watson Crick Mechanism of inheritance DNA 1953
Gregor Mendel Contemporary of Darwin father of
genetics -1866 Heritable traits dominance
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Peter Rosemary Grant
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Daphne Major
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Started research project on Darwin finches in
1973.
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Geospiza fortis
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Graph showing the distribution of beak depths for
medium ground finches in Year 1
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la Niña Drought
el Niño Rains
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Drought (la nina)
Wet (el nino)
39
Following the drought of 1977, 85 of the medium
ground finch population died.
  • In 1975, the rainy season came and went with nary
    a drop of rain (el Niño)

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Year 3 Data

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Caltrop seeds (Tribulus)
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  • This demonstrates natural selection, but the
    story is not quite over
  • The year of the drought, no young were produced
  • After the drought, the 15 that survived
    represented birds with larger bills.
  • These individuals did breed the following year.
  • What do think their offspring looked like?
  • (Small beaks? Medium beaks? Big beaks?)
  • This is evolution.

44
Other evidence for evolution
  • Common structures (homologous)
  • Analogous structures (convergent evolution)
  • DNA Research
  • Fossil Record
  • Embryonic development
  • Vestigial Organs Structures
  • Imperfections in Structure
  • Drug-Resistant Bacteria

45
Homologous Structures common ancestor
46
Homologous Structures
47
Convergent Evolution Physical adaptations to
similar ecological conditions
48
Convergent Evolution
49
DNA
  • - species that appear to be more
  • distantly related from their positions
  • in the fossil record are found to have
    correspondingly greater differences in
  • their DNA than species that appear
  • more closely related in the fossil record.

50
Fossils
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Conservation Connection
  • It is not the strongest of the species that
    survives, nor the most intelligent,
  • but the one most responsive to change.
    Charles Darwin

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Punta
Alta a perfect catacomb for monsters of extinct
races
57
  • We are changing the world faster than species are
    able to adapt to these changes.

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Humans as an Evolutionary Force
  • Human-induced evolution caused by unnatural
    selection through harvest of wild animals
    (Allendorf, F.W. and J. J. Hard. 2009. PNAS. Vol.
    106)
  • The nature of fisheries- and farming-induced
    evolution (Hutchings, J.A. and D.J. Fraser.
    2007.Molecular Ecology. Vol.17)
  • Rapid human-induced evolution of insecthost
    associations (Singer, M., C.D. Thomas and C.
    Parmesan. 1993. Nature. Vol. 366)
  • Humans as the World's Greatest Evolutionary Force
    (Palumbi, S.R. 2001. Science. Vol. 293)

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Evolution BooksThe Old Classics
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Evolution BooksThe New Classics
66
  • It is a century now since Darwin gave us the
    first glimpse of the origin of species. We know
    now what was unknown to all the preceding caravan
    of generations that men are only fellow-voyagers
    with other creatures in the odyssey of evolution.
    This new knowledge should have given us, by this
    time, a sense of kinship with fellow-creatures a
    wish to live and let live a sense of wonder over
    the magnitude and duration of the biotic
    enterprise.

Aldo Leopold
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