http://upload.wikimedia.org/wikipedia/commons/4/44/Haeckel_Prosobranchia.jpg

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n
Evidence for Evolution

• http//upload.wikimedia.org/wikipedia/commons/4/44
  /Haeckel_Prosobranchia.jpg

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As European civilization grew its people had the
curiosity and ambition to explore the edges of
the Earth, and across vast oceans and in distant
lands they found amazing creatures at once
incredibly different to those at home, and yet
remarkably the same. There was no explanation
for such magnificent diversity and enduring
similarity until one man, visiting distant isles,
had an incredible revelation . . .
http//www.ronscobie-marineartist.com/Brierholme2
0oval.JPG
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• Evolution
• The process by which species and populations
  change over time
• Decent with modification . . .

http//www.cambridgeshire.gov.uk/NR/rdonlyres/F384
0F96-432F-4D02-ADED-4C791BBBC29E/0/Darwin.jpg
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Darwin and Natural Selection

• Variation exists within species
• Organisms produce more offspring than the
  environment can provide for
• Competition exists among individuals
• Organisms whose variations best fit the
  environment will survive, reproduce, and pass on
  their advantageous variations to their offspring

Pojeta, John Jr. and Dale A. Springer 2001
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http//upload.wikimedia.org/wikipedia/commons/thum
b/7/70/Phylogenetic_tree.svg/800px-Phylogenetic_tr
ee.svg.png
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Evidence has Been Found in Many Places

• Geology and the Fossil Record
• Biogeography
• Developmental Biology
• Molecular Biology

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Fossils provide the dimension of time in the
story of evolution
http//www.gutenberg.org/files/20417/20417-h/image
s/image158.jpg
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Principle of Superposition
Sedimentary rock layers are formed sand grain by
sand grain, gravel bit be gravel bit, until a new
layer of rock is formed, new layers form on top
of older layers, and so the youngest layers are
always at the top of a rock formation and the
oldest at the bottom.
Interesting to know Steno was one of the first
to recognize fossils when in 1667 recognized the
similarity of tongue stones to sharks teeth
http//www.ucmp.berkeley.edu/history/steno.html
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Geological Cross Section of the Grand
Staircase-Escalante National Monument in Utah
Ayala, Francisco J et al., 2008
http//photography.nationalgeographic.com/staticfi
les/NGS/Shared/StaticFiles/Photography/Images/POD/
s/staircase-escalante-building-522011-xl.jpg
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Radioisotope Dating

• When radioactivity was discovered, so was a way
  to measure the age of rocks
• Rocks are made of atoms, some are undergoing
  radioactive decay
• This means they emit particles and energy at a
  measurable constant rate
• Measurements can be taken to see how many atoms
  have decayed, which provides insight into how old
  the rock is
• This is called the natural clock of geology

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http//science.howstuffworks.com/carbon-14.htm/
and http//sps.k12.mo.us/jms/cartoon.htm and
http//www.ipj.gov.pl/en/szkolenia/glossaryEN.htm
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http//media-2.web.britannica.com/eb-media/90/790-
004-A1844BBC.gif
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http//www.nzetc.org/tm/scholarly/Bio10Tuat02-fig-
Bio10Tuat02_P001a.html
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Law of Fossil Succession

• Fossils are the remains of once living organisms
• The vast majority of fossils are the remains of
  the hard parts of extinct organisms
• The types of fossils found differ because life on
  Earth has changed

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• Fossils are the primary evidence for how species
  evolved over time
• Hundreds of thousands of fossils show succession
  of forms over time
• Including fish to amphibian
• Amphibian to reptile and reptile to mammal
• Importantly, fossils give consistent evidence of
  systematic change over time without any reversals
• (Ayala, Francisco J et al.
• 2001)

http//labspace.open.ac.uk/file.php/4128/S182_7_00
5i.jpg
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Common Structures
Fossils can show homologies between species that
show a common ancestor (as can comparative
anatomy) Homologies are structures two or more
species have in common though they may not be
used for the same purpose
http//www.nap.edu/openbook.php?record_id6024pag
e14 and http//upload.wikimedia.org/wikipedia/com
mons/6/64/Handskelett_MK1888.png
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Whereas useless in this circumstance, these
rudiments... have not been eliminated, because
Nature never works by rapid jumps, and She always
leaves vestiges of an organ, even though it is
completely superfluous, if that organ plays an
important role in the other species of the same
family. Etienne Geoffroy Saint-Hilaire 1798
http//en.wikipedia.org/wiki/C389tienne_Geoffroy
_Saint-Hilaire
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Developmental Biology

• Evolution is not perfectly efficient
• As new species evolve from old species they
  often carry with them old traits that no longer
  serve any purpose
• These traits are known as vestigial traits and
  can by anatomical, biochemical or behavioral in
  nature
• These traits are further evidence of an
  ancestral relationship

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Blind Mole Rat Cant see a thing with their eyes
covered by skin flaps, but still has eyes
Ostriches still have wings, but cannot fly
Coccyx the tailbone of a human, a vestigial
attribute from our tailed ancestors
Whale Note the bones labeled c, they are the
vestigial memory of hind legs
http//en.wikipedia.org/wiki/Vestigial and
http//farm2.static.flickr.com/1166/1186161894_7f6
9d19604.jpg?v0
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Biogeography
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Biogeography

• There is an enormous amount of diversity, and yet
  many common forms and migrations influence on
  the development of new species
• Explains the multiplicity of related species in
  remote localities
• Explains the absence of many organisms on islands
  and multiplicity of a few kinds

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Phylogenetic Tree of Galapagos finches
http//porpax.bio.miami.edu/cmallery/150/unity/c1
x17b-finches.jpg
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Finches in Context of Migration from Mainland to
Island
http//www.doe.mass.edu/mcas/student/2007/question
.asp?GradeID100SubjectCodebio_hsQuestionTypeNa
meQuestionID5357
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Molecular Biology

• Provides the mechanism of evolution
• Provides evidence of a common ancestor
• Provides additional information about when
  speciation occurs and history of relationships
  between species by examining the molecular clock
  and pseudogenes

http//www.ch.cam.ac.uk/magnus/molecules/nucleic/d
na1.jpg
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Mechanism for Evolution

• In the year following Darwin, all of this
  evidence accumulated in favor of evolution, yet
  until the discovery of modern genetics, the
  mechanism for variation was not known
• Greg Mendel first noted patterns in heredity,
  however with Watson and Cricks discovery of the
  double helix we have now come so far as to
  understand chromosomes, genes and DNA
• DNA is the ultimate source of variation, when
  sperm, eggs, or daughter organisms are created,
  the DNA of the parent must be replicated to
  provide the template of the organism
• When DNA replicates it is not a perfect process
  and small errors will occur, most are corrected
  in the process, but some are not, these are
  mutations
• Mutations provide the variation between
  individuals within a species necessary for
  natural selection to occur

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http//universe-review.ca/I11-33-mutations.jpg
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A Common Basis

• All living things share the same biochemical
  machinery from algae to elephants
• Proteins are virtually identical from fruit flies
  to mice to humans and all life uses the same 20
  amino acids
• All living things use the same biochemical system
  to pass genetic information from one generation
  to another
• This adds enormous weight to the idea of a common
  ancestor

http//www.ageds.iastate.edu/meat/images/dna2.gif
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All living organisms share common structures for
DNA, RNA, and the 20 amino acids
http//www.talkorigins.org/faqs/molgen/
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Molecular Clock

• Genes have been used to reconstruct the
  evolutionary history of species
• Mutations occur constantly
• Genes evolve at different rates because some
  genes are more tolerant to change than others
• When geneticists consider this they can create
  maps of when species may have diverged

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Pseudogenes and Phylogenetic Trees

• As species change some genes that were once
  useful lose their functionality
• They are still passed on to offspring, but are
  not expressed, just carried along like excess
  baggage
• They are useful to determine past relationships
  between species
• The degree of similarity of these genes between
  different species reflects the degree of
  relatedness as it is improbable they evolved
  independently

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Works Cited

• Ayala, Francisco J et al. 2008. Science,
  Evolution, and Creationism. The National
  Academies Press. National Academy of Science and
  Institute of Medicine. Washington D.C.
• Bowler, Peter J. 2003. Evolution The History of
  an Idea. University of California Press. Berkley
• Gardner, Robert. 2005. Genetics and Evolution
  Science Fair Projects. Enslow Publishers.
  Berkeley Heights. 123-124
• Krukonis, Greg and Tracy Barr. 2008. Evolution
  for Dummies. Wiley Publishing, Inc.
• Larson, Edward J. 2004. Evolution The Remarkable
  History of a Scientific Theory. The Modern
  Library. New York
• Hilaire, Geoffroy.1798. "Observations sur l'aile
  de l'Autruche, par le citoyen Geoffroy", La
  Decade Egyptienne, Journal Litteraire et
  D'Economie Politique 1 (pp. 4651). Embedded in lt
  http//en.wikipedia.org/wiki/Vestigialcite_note-3
  gt
• Pojeta, John Jr. and Dale A. Springer. 2001.
  Evolution and the Fossil Record. American
  Geological Insitute. Alexandria, Virginia
  ltagiweb.orggt
• Taylor, Paul D. 2000. Eyewitness Books Fossil.
  Dorling Kindersley. London