Transcript Evolution Power Point to Guided Notes

Theory of Evolution
Gradual change in a species
through adaptations over time.
Artificial Selection.
Darwin noted that farmers and animal breeders bred
for certain variations in plants and animals to
improve crops and livestock.
They would select for breeding only the largest
hogs, the fastest horses, or the cows that produced
the most milk.
Natural Selection (“Survival of the Fittest”)
Favorable variations over time that increase the
organism’s ability to survive contribute to an
organism's fitness in its environment. These
changes are passed along to offspring
Natural selection also takes place without human
control or direction.
Struggle for Existence
Members of each species compete regularly to
obtain food, living space, and other necessities
of life.
Fitness
Ability of an individual to survive and reproduce
in its specific environment . Fitness is the result
of adaptations over time
Adaptation
Any inherited characteristic that increases an
organism's chance of survival
Evolution of Brains:
Charles Darwin
Natural Selection:
“Survival of
fittest”
Fittest live to
reproduce
Competition for
resources
Best adapted
species survive
HMS Beagle Voyage 1835
Darwin left on a
around the world
voyage on the HMS
Beagle in 1835.
HMS Beagle Voyage 1835
One of the places that
Darwin visited was the
Galapagos islands
Because of their
remoteness Darwin
studied the animals he
found there
Darwin studied the
changes in the beaks of
Finches
Darwin’s key ideas:
REPRODUCTION:
– Organisms produce more offspring than can
survive
VARIATION
– Variety in traits exist
SURVIVAL OF THE FIT
– Some traits allow survival & are passed on
Over time certain variations make up most
of a population & they may be different
from their ancestors
Evolution Evidence:
1. Adaptations
2. Fossils
3. Comparative anatomy
4. Comparative embryology
5. Comparative Biochemistry
6. Plate Tectonics
Adaptations
Adaptations:
features suited to a
particular environment
that allow organisms to
survive
Inuit people, who live
in the extreme cold of
the Arctic, have short,
stout bodies that
conserve heat.
Adaptations
The Masai
people, who live
in the arid lands
of eastern Africa,
have tall, lean
bodies that
disperse heat
well.
Camouflage
Enables a species to blend with their
surroundings to avoid detection by predators
Mimicry
Enables one species to resemble another
species; may provide protection from predators
or other advantages
The smaller Viceroy
butterfly that is tasty to
birds mimics the larger
Monarch which tastes
bitter.
Leaf Insect on the right is
almost indistinguishable
from a actual leaf on the left
Bird Beak Adaptations:
Plant Adaptations:
Venus Fly Trap
Captures Animals
Acquires Minerals
For Photosynthesis
Leaf Adaptations:
Succulents
1. Thick
2. Store Water
3. Prevent
Drying out
Leaf Adaptations:
Pine Needles
Shed snow
Less water loss
Reduced surface
area
Tolerate wind
Flower Adaptations:
Fly pollination:
Hair along petals
Putrid smell
Bee pollination:
Smooth petal
Sweet smell
Fossil
Evidence:
Once living
remains of
organisms
Limited:
1. Type of material
preserved (bone,
shell, impressions,
amber)
2. Incomplete record
3. Easily disrupted
Plant Fossil Evidence:
Comparative Anatomy:
Structural similarities link related
species
Comparative Anatomy
Structures:
Analogous:
1. Different ancestors
2. “analogy”=like
3. Different underlying
structures
4. Same Function
5. Similar Environments
Homologous:
1. Same ancestor
2. “homo”=same
3. Same underlying
structures
4. Different Functions
5. Different
Environments
Analogous Structures
Different underlying structures
(different ancestors)
Same function, similar environments
Bird Wing
Fly wing
Homologous Structures:
Same underlying structures, different functions,
different environments & common ancestor
Vestigial Structures
Structures in a present-day organism that no longer
serve its natural purpose, but was probably useful to an
ancestor, provides evidence for evolution
Mole Rat has skin
covering it’s eyes
making them a
vestigial organ
Whale has pelvis
bone
Comparative embryology:
Similar embryo development in closely related
species
Chicken
Turtle
Rat
Comparative Biochemistry
Similar DNA
sequences and
similar gene
segments of the
DNA= Code for
similar traits in
closely related
species
How do you define a Species?
Same Species Must:
Show similar
characteristics
Successfully
interbreed
Produce fertile
offspring
Donkey + Horse =
Mule (infertile)
In Darwin’s time, it was
proposed that layers of rock,
such as those that make up
the distinct layers of
sandstone, form very slowly.
The Earth was moved up by
forces beneath Earth's
surface creating changes to
the sea floor and to form
mountain ranges.
The resulting rocks,
mountains, and valleys are
then shaped by a variety of
natural forces—including
rain, wind, heat, and cold
temperatures.
Most of these geological
processes operate
extremely slowly, often over
millions of years.
Movement of
Tectonic Plates
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Summary of Darwin's Theory
1. Individual organisms differ, and some of this variation is
2.
3.
4.
5.
heritable.
Organisms produce more offspring than can survive,
and many that do survive do not reproduce.
Because more organisms are produced than can
survive, they compete for limited resources.
Each unique organism has different advantages and
disadvantages in the struggle for existence. Individuals
best suited to their environment survive and reproduce
most successfully. These organisms pass their heritable
traits to their offspring. Other individuals die or leave
fewer offspring. This process of natural selection
causes species to change over time.
Species alive today are descended with modification
from ancestral species that lived in the distant past.
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The Six Evidences of Evolution
Foldable
Front
The Six Evidences of
Evolution
Back
Plate Tectonics
Picture
Fossils
Definition:
Comparative Biochemistry
___________
Embryology
___________
Adaptations
___________
Comparative Anatomy