Download chapter 16 section 4 notes

Chapter 16 Section 4
Evidence of Evolution
DO NOW
• Read the following passage on Earth’s
history of life and explain:
• “Of this history, we possess the last
volume alone…Of this volume , only here
and there a short chapter has been
preserved; and of each page, only here
and there a few lines.”
Fossils Provide a
Record of Evolution
• ________ are preserved or
mineralized remains of an
organism
• They provide a record of past
________________
• ________ fossilized species
are different from newer ones
• They show _______ between
great groups of organisms
Scientists agree on
three major points
1) Earth is about __________ years old
2) Organisms have inhabited the Earth for
most of its history
3) All organisms living today ________
from earlier, simpler life forms
Fossil records are not complete
• Many species live in environments where fossils
do not form
• Most form where organisms are
____________buried in fine sediments
deposited by water, wind, or volcanoes
• Organisms living in ___________,___________,
_______________ will probably NOT form
fossils
• Paleontologists study fossils and can predict
their age using radiometric dating
Whale evolution
Biological Molecules contain a
record of evolution
• Proteins- Species that evolved from an ancestor
in the distant past should have ________ amino
acid differences than those who shared a
common ancestor more recently
(Example: hemoglobin differences to humans:
gorilla=1, monkey=8, mouse=27, chicken=45,
frog=67)
• Nucleic acids- comparing nucleotide
sequences also shows how long it has been
since two species _______________
• Together proteins and nucleic acids support the
fossil record
Anatomy suggests common
ancestry
• __________ ___________
present in an organism but are
reduced in size and either have
no use or have a less important
function than in other related
organisms
Examples: _______________
__________________________
• Homologous structures- structures that
share __________ ____________
Example: forelimbs of vertebrates are
made form the same basic groups of
bones
Development also suggests
common ancestry
• Embryo development is __________ in
organisms with common ancestry
How quickly does evolution
occur?
• _______________- gradual change over
long periods of time leads to species
formation
• Punctuated equilibrium-periods of
__________change in species are
separated by periods of little or no change
( caused by major environmental changes)