Download Origin of Life

Evolution: A theory that life
changes over time
Charles Darwin
• His five year voyage on the HMS Beagle
led him to eventually develop the theory
of evolution
The three patterns of biodiversity:
• Species vary locally
• Species vary globally
• Species vary over time
Malthus:
“human pop will
double every 25
yrs.”
(more competition)
Who helped
Darwin to
develop his
idea of
Natural
Selection?
Lyell:
”uniformitarianism”
Geological process
that shape earth are
the same processes
that shaped earth
millions of years ago
Hutton:
The earth is much
older than a few
thousand years.
Jean Baptiste
LAMARCK
Sir Charles
DARWIN
LAMARCK:
1. Acquired Characteristics
2. Inheritance of Acquired Characteristics
An example of Lamarck’s reasoning
• Question: How would Lamarck explain the evolution of
•
the Giraffe?
Find where Lamarck is using his two laws to falsely
explain evolution in this case.
Artificial Selection
• Darwin’s use of artificial selection allowed
him to recognize that variations were the
raw material for evolution
Darwin’s Theory of Evolution
Charles Darwin
Natural Selection
Struggle for
Existence
Variation and
Adaptation
Survival of the Fittest
Populations compete
for food. Some
survive
Individuals have
variations. Some are
better suited than
others
Some are better
adapted and will
survive and have
more off spring
*show brainpop: Darwin and then Natural selection
Natural Selection
• How is the “visual summary” on page 462
an example of natural selection?
What does Darwin’s theory
suggest?......Common Descent!
Evidence of Evolution :
Biogeography – where organisms live now and
where their ancestors lived in the past
• Closely Related but
Different
• Distantly Related but
Similar
Evidence for Evolution
• The age of earth and fossils of
intermediate species
Evidence for Evolution:
Comparative Anatomy
• Homologous
structures
Evidence of Evolution:
comparative anatomy
• Vestigial Organs
Evidence of Evolution:
Comparative Anatomy
• Embryology
Genetics and Molecular Biology
Investigating Common Descent
Chapter 16 Assessment
pg. 476 - 479
• Chapter 16.1 # 1-4
• Chapter 16.2 # 8-13
• Chapter 16.3 # 16-18
• Chapter 16.4 # 25-29
• Standardized Test Prep #1-11
Origin of Life
How Old is
Earth?
If 1 year is equal to a
second…….
• a half hour would take
you back to 5 AD
• 3 weeks would take
you back to 100, 000
years (first human life)
•20 years would take
you back to the
Cambrian age
(500million years ago)
So, how did life begin?
Three Ideas
Creationism
(faith based)
Spontaneous
Generation
(observation)
Modern
Scientific Theory
(scientific method)
God created
all living things
Life arose from
non-living matter
Ex. Dirt, water
Life arose through
chemical
reactions
Spontaneous Generation
• all living things developed from nonliving matter
(ie. rocks, mud, rotting meat etc)
Who proved spontaneous
generation false?
Francesco Redi (1626 – 1697)
Even though Redi disproved
spontaneous generation it was
not accepted.
Why?
Louis Pasteur
Pasteur also dispelled the
myth of spontaneous
generation, proving that all
life comes from pre-existing
life (biogenesis).
What is the purpose of the
curved neck flask in
Pasteur’s experiment?
Modern Scientific Theory:
Abiogenesis
The Appearance of Life
on Earth Required:
• Formation of simple
organic compounds
• Formation of complex
organic compounds
• Enclosure of these
organic compounds
• Growth, metabolism
and reproduction
First Forms of Life
Prokaryotic
Eukaryotic
PATTERNS OF EVOLUTION
Divergent
Convergent
Coevolution
Two or more
Two or more
RELATED species UNRELATED
become dissimilar species become
similar
Two or more
species live in
close interaction
with one another
Red fox: Red colour
Insects: longer probes to
drink nectar
-wings to fly from flower to
flower
Flowers: bright colours
Sweet smell
=blend to forest
Kit fox: Sandy colour =
blend to plains, large ears
for cooling
Live in Different
Environments
Plains vs Forest
Cactus & Euphorb
-both store water in
stems and have spiny
skin
Both live in Desert
Same
Environment
Same
Environment
Convergent Evolution
Divergent Evolution