Download Theory of Evolution Notes - Effingham County Schools

Evolution Notes
What exactly is evolution?
_____________________________ is the biological change process by
which descendants come to differ from their ancestors.
Or, simply _________________________________________________.
Theories of __________________ change set the stage for the
evolutionary theory.
Catastrophism

Natural disasters such as __________________________ and
_________________________________________have happened
often during Earth’s long history

These events shaped ____________________________ and caused
species to become ______________________ in the process
Gradualism

Landforms result from ___________ changes over a
_____________ period of time

Creation of canyons, laying down of soil
Uniformitarianism is the prevailing theory of geologic change.

Geologic processes that shape Earth are ___________________
through time
Catastrophism:
Gradualism:
Uniformitarianism:
Evidence for evolution came from several sources.

Fossils provide ______________________________ of evolution.

Fossils in ___________________ layers are more primitive than
those in the upper layers.
o Older layer = older fossil
The study of _____________________________ provides evidence of
evolution.
o island species most closely resemble nearest mainland species
o populations can show variation from one island to another

Biogeography is the study of the __________________________
of organisms around the world
_____________________________ provides evidence of evolution.
o identical larvae, different adult body forms
o similar embryos, diverse organisms
The study of _____________________ provides evidence of evolution.

Homologous structures are ___________________ in structure but
different in function.

Homologous structures are evidence of a _____________________
ancestor.
o Examples: human hand, mole foot and bat wing

Analogous structures have a ______________________ function

Analogous structures are not evidence of a common ancestor.
o Examples: insect wing and bat wing

Vestigial structures are remnants of organs or structures that had a
function in an ____________________ ancestor.
o Ostrich wings are examples of vestigial structures.
How can I remember?
Homologous Structures:
Analogous structures:
Vetsigial Strucrures:
Early scientists proposed ideas about evolution.


_____________________________: classification system from
kingdom to species
____________________________: species shared ancestors
rather than arising separately

____________________________: more-complex forms developed
from less-complex forms

__________________________: environmental change leads to use
or disuse of a structure
Then there was Charles Darwin.

Influenced by ____________________________ views of gradual
geologic change

1831 - ________________________________ traveled to South
America

Found much evidence to support Lyell’s views

Formulated his own opinions
Darwin observed differences among island species.

Variation is a difference in a_______________________ trait.
o Galápagos tortoises that live in areas with tall plants have long
necks and legs.
o Galápagos finches that live in areas with hard-shelled nuts have
strong beaks.
Species may somehow be able to ________________ to their
surroundings…

An adaptation is a feature that allows an organism to
____________________ survive in its environment.
o Species are able to adapt to their environment.
o Adaptations can lead to ____________ change in a population.
Darwin observed fossil and geologic evidence supporting an ancient Earth.

Darwin found fossils of extinct animals that
_____________________________ modern animals.

Darwin found fossil shells high up in the Andes mountains.

He saw land move from underwater to above sea level due to an
______________________________________.

Darwin’s observations supported Lyell’s theory that daily geologic
processes can add up to great change over a _________________
period of time.

Darwin extended his observations to the _____________________
of organisms.
Several key insights led to Darwin’s idea for natural selection.

Darwin noticed a lot of ______________________________ in
domesticated plants and animals.
o Traits that weren’t in their wild relatives

In order for artificial or natural selection to occur, the trait must be
___________________________________________.

Heritability is the ability of a trait to be passed down.
Artificial Vs. Natural Selection

Artificial selection is the process by which humans ______________
traits through breeding.

Natural selection is a mechanism by which individuals that have
inherited beneficial adaptations produce__________________
offspring on average than do other individuals.
Natural selection explains how evolution can occur.
 There are four main principles to the theory of natural selection.
o Variation
o Overproduction
o Adaptation
o Descent with modification
Principle
Variation
Overproduction
Adaptation
Descent with modification
What is it?
Survival of the Fittest?

Fitness is the measure of _________________________ ability and
ability to produce more offspring.
o Jaguars with larger teeth and jaws have a higher fitness than
other jaguars in a population.
o Other jaguars reproduce less because they were less fit.
Natural selection acts on ________________________________
variation.

Natural selection can act _________________ on traits that
already exist.

Structures take on_____________________ functions in addition
to their original function.
New __________________________ is furthering our understanding of
evolution.
Fossils provide a _______________________ of evolution.

Paleontology is the study of ________________________ or
extinct organisms.
o Paleontology provides ________________________ to
support evolution.

Molecular and genetic evidence ________________________ fossil
and anatomical evidence.
o Two closely-related organisms will have __________________
DNA sequences.

Evolution _______________________ all fields of biology.
o Scientist from many fields contribute to the understanding of
evolution.
o The basic principles of evolution are used in many scientific
fields.