Evidence of EvolutionEvidence of Evolution

1. Fossils :• Preserved remains of a REAL organisms.• A fossil is not a the actual bone, the bones get

buried and mineral deposits take their place over time.

• Actual record of past life forms• Able to “date” and link lineages

• Older fossils are in deeper layers of rock

• Carbon dating used to estimate age

Evidence of EvolutionEvidence of Evolution

2. Molecular Similarities• All organisms’ DNA is made up of the same four

nucleotides (A-T, G-C)

• All organisms are structurally made up of the four organic compounds: nucleic acids, carbohydrates, proteins, and lipids

• Species that share a more recent ancestor have fewer amino acid differences in their proteins

• Shows same relationships from fossils

Molecular Similarities: HemoglobinMolecular Similarities: Hemoglobin

Species # Amino acids different than humans

Gorilla 1

Rhesus monkey 8

Mouse 27

Chicken 45

Frog 67

Lamprey 125

Evidence of EvolutionEvidence of Evolution

3. Homologous Structures / Similar anatomy:• Similar body structures/bones with different functions

Evidence of EvolutionEvidence of Evolution

4. Similar vertebrate embryos:• Early in development, vertebrate embryos have

similar characteristics

• In the individuals above, there is a gill pouch present in each vertebrate. However, that does not mean that humans have gills because we don't. It is really thyroid glands, not gills that is in humans. Comparative embryology shows species with similar ancestors.

Which one is human?Which one is human?

1 2 3 4 5 6 7 8

Which one is human?Which one is human?

1 2 3 4 5 6 7 8

Which one is human?Which one is human?

1 2 3 4 5 6 7 8

Did you guess?Did you guess?

Evidence of EvolutionEvidence of Evolution

Practice Questions in Review BookPractice Questions in Review Book

Page 171 & 172 Questions 13, 14, 16 and 26

While answering multiple choice please underline key words, write what you know and cross off answers you know are wrong.

Page 173 Question 41

Before answering question 41 read the section in the book entitled Natural Selection on page168. Write the answer on the sheet provided. Use full sentences after each bullet!