Evolution: The Evidence

1
Evolution The Evidence

• You will be able to explain how fossils and
  homologous structures are used to show the
  evolution of a species

2
Evolution The Evidence

• Importance of fossils
• Provides blue prints of organisms
• determine age of rock layer (law of superposition
• tells environment of land then

3
Evolution The Evidence

• Fossils provide us with homologous structures
• Homologous Structures are body parts from two
  different organisms which have a similar
  structure and design
• Body Parts Contain same number of bones and
  muscle attachments.

4
Evolution The Evidence

• Homologous Structures
• Pectoral Fin-Whale Arm-
  Human Wing- Chicken
• All basically have same basic design much
  different uses however, (determined by
  environment)

5
Evolution The Evidence

• Evolution also supported by the study of
  Embryology
• Embryology is the study of developing embryos
• Scientists can see very diverse organisms as
  adults have very similar beginnings (p.553)

6
Evolution The Evidence

• Human Embryos have
• tails
• gill slits (remnants)
• share this trait with majority of all vertebrate
  organisms
• shows possible link to an aquatic ancestor
  (fish????)
• Eventually traits disappear EXCEPT

7
Evolution The Evidence

• As an adult you still have a tail bone, called
  the coccyx bone
• Remnant of this bone plus other things such as
  the appendix, and ear muscles are called
  Vestigial Structures
• Vestigial Structures are organs or body parts
  that no longer have a purpose

8
Evolution The Evidence

• Evolution can also be studied at cellular level
  as well
• All living things made up from cells
• For all living organisms made the molecule for
  life is DNA
• DNA made up of 6 basic elements
• Oxygen, Nitrogen, Hydrogen, Phosphorus, Sulfur,
  Carbon

9
Evolution The Evidence

• All cells contain the same building blocks of
  proteins, fats, and carbohydrates
• Most cells have a nucleus and a nuclei have gel
  like layer of cytoplasm
• More closely related the organism, more they have
  in common

10
Evolution The Evidence

• Human Question?
• Human DNA is 99 identical to chimpanzee DNA
• Humans Chimpanzees, Apes belong to group of
  mammals called PRIMATES

11
Evolution The Evidence

• ALL PRIMATES HAVE THESE TRAITS
• Opposable thumbs, binocular vision, rotating
  shoulder, large brain