Transcript Evidence of Evolution

Evidence of Evolution
Fossils Provide
Evidence
Animal fossils show a pattern of
development from early
ancestors to their modern
descendants.
There are gaps in the fossil
record.
Fossils are rare
http://www.google.com/imgres?imgurl=http://www.wallsofthewild.com/pterodactyl.jpg&imgrefurl=http://www.wallsofthewild.com/pter.htm&usg=__9caIuOdNvnUNeTtJd_BwijJIK5M=&h=479&w=800&sz=100&hl=en&start=0&zoom=1&
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FOSSIL:
The preserved or
mineralized remains (bone,
petrified tree, tooth, or shell)
or imprint of an organism
that lived long ago.
http://www.maropeng.co.za/images/uploads/fossil_lg.jpg
Three Major Points
• Earth is about 4.5 billion years old
• Organisms have inhabited the earth for
most of its history
• All organisms living today evolved from
earlier, simpler life-forms.
Crinoid
fossil
Found in an 800 MILLION
year old rock from Indiana
http://www.youtube.com/wat
ch?v=cZcomBnNKXg
Paleontologist
Scientist who studies
fossils.
http://blogs.answersingenesis.org/museum/pictures/Dino-dig-8-30-06-0151.jpg
Paleontology
•
Paleontologists can determine
how old fossils are.
•
They use radiometric dating to
determine the half life.
•
http://www.furryelephant.com/con
tent/radioactivity/half-lifesimulation/
Evolution of
Whales
http://biologos.org/uploads/static-content/Figure_1.png
Biological Molecules
Provide Evidence
Proteins
Amino acids are the building blocks of proteins
Amino acid + amino acid + amino acid = PROTEIN
The more amino acids two species have in common, the
more closely related they are.
Hemoglobin Comparisons with humans
Species
Amino Acid
differences
Gorilla
1
Rhesus monkey
8
Mouse
27
Chicken
45
Frog
67
Lamprey
125
Biological Molecules
Provide Evidence
Nucleic Acids
Scientists can determine the number of nucleotide
differences among organisms to see how closely related
they are.
They make DNA comparisons.
Anatomy & Development
Suggest Common Ancestry
Vestigial Structures
Homologous Structures
Development of Embryos
Vestigial
structures:
Structures that are present in an
organism but are reduced in
size and are no longer useful.
Examples: Wings of flightless
birds, fingernails on manatee
fins, and goosebumps (not a
structure but a reaction).
Homologous
structures
Structures that similar in form
but different in function.
Examples: Forelimbs of
vertebrates
Development of Embryos
Guess the Embryo
http://www.pbs.org/wgbh/nova/evolution/guessembryo.html