Download CH # 5C

Chapter 5C
• The Evolution of Living
Things
Change Over Time…..
• Adaptation – a change that helps an
organism survive and reproduce in its
environment
•
Species…..
• A group of organisms that can interbreed
and produce fertile offspring
• Humans can mate with humans to make
more humans
• Strawberry poison arrow frogs can mate
with other strawberry poison arrow frogs
and produce fertile offspring.
Not Species…..
• Horses mate with donkeys and produce
mules….which are NOT fertile
• Female horse * Male donkey – MULE
• Male horse * Female donkey - HINNY
Mule…..
Hinny…..
Do Species Change Over Time?
• Scientists the Earth is over 4.6 billion years
old
• Scientists believe that many species have
died out and many have appeared
• The process of gradual change over time is
called EVOLUTION
Evidence of Evolution…..
• Fossils – the trace remains of an organism
the lived long ago, most commonly
preserved in sedimentary rock
• Fossil Record – a historical sequence of life
indicated by fossils found in layers of the
Earth’s crust
•
Evolution of the Whale…..
Comparing Organisms…..
Section Two…..
•How Does
Evolution
Happen ?
Charles Darwin…..
• 1831 @ 21 years of age
• College Graduate
• Dad wanted him to be a
doctor
• Earned a degree in
theology
• Interested in plants and
animals
• 5 year voyage around the world
• Served as the naturalist
• British ship --- HMS Beagle
•
His Adventure…..
Darwin’s Finches…..
Darwin’s Ideas About Breeding
• Many farmers grew plants and animals with
desired traits
• TRAIT – a characteristic that can be passed
from parent to offspring
• Selective Breeding – when humans select
which plants and animals can reproduce
…..Ideas on Population Growth
• Spoke with Thomas Malthus
• Humans reproduce quickly
• Food supplies could not support unlimited
population
• Limited by starvation, disease, competition, and
predation
…..Ideas about Earth’s History
• Darwin learned from a book Principles of
Geology that the Earth was formed over a
long period of time.
• Long enough for changes to occur
Darwin’s Theory of Natural
Selection
• After 20 years of waiting……..
• Published On the Origin of Species by
Means of Natural Selection
• Natural Selection – process by which
organisms that are better adapted will
survive and reproduce more successfully
Section 3
• Natural Selection in
Action
• Changes in Populations
• Adapting to Hunting
• 1% of Males born with
w/out tusks
• NOW……15% of Males
born w/out tusks
Insecticide Resistance…..
Competition for Mates…..
Formation of New Species…..
• Speciation – the making of a new species