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Evolution
Evolution
This unit explains the
scientific aspect of
evolution.
There are multiple views on evolution all of which
have significant evidence for backing.
Everyone is entitled to their own opinion and we
will discuss multiple views and opinions.
What is Evolution?
Evolution is
a scientific explanation for the
diversity of life based on a collection scientific
data, observations and hypotheses.
The Theory of Evolution- Change over time by
which a modern organism has descended from
an ancient organism.
This unit explores multiple explanations for
evolutionary change.
Charles Darwin
 One
of many scientists who has studied evolution.
 He has contributed the most amount of data and
research to the theory of evolution.
 Sailed on a ship (H.M.S. Beagle) around the world,
most notably in the Galapagos Islands, making
observations and collected evidence which
supports his theory.
 Published the results of his work in the book; On
the Origin of Species.
Descent with Modification
Idea that Darwin
proposed also know as
Darwinism:
States that over long periods of time natural
selection produces organisms that have different
structures, establishes different niches or occupy
different habitats.
Define the Following Terms
 Fossils
 Artificial
Selection
 Struggle for Existence
 Fitness
 Adaptation
 Survival
of the Fittest
 Natural Selection
 Common Descent
 Homologous Structures
 Vestigial Organs
Darwin’s Evidence of Evolution
Darwin
argued that living things have been
evolving on Earth for millions of years.
His evidence for this process could be found in
the fossil records, geographical distribution of
species, homologous structures of living
organisms and embryology.
Population Growth
The increase in
number of a species as well as
sustaining the existence of the species on earth.
Certain factors must occur for population growth
to occur.
Many factors influence population growth.
Population growth and population dynamics can
impact population genetics.
Genetics has a direct relationship to evolution.
Summary of Darwin’s Theory
 Individual
Organisms differ, and some of this variation is
heritable (first connection between evolution & genetics).
 Organisms produce more offspring than can survive
(creates competition), and not all can reproduce.
 The offspring will fight for limited resources in order to
survive.
 Each has advantages & disadvantages in the struggle
for existence. Those organisms that survive, pass these
traits on to their offspring.
 Species alive today are descendents of those that
survived in the past.
Other Thoughts of Evolution
James Hutton- Earth
shaped by geological forces
that took place over extremely long periods of
time.
Thomas Malthus- Principle of Population, predicts
that human population will grow faster then food
& space needed to sustain life.
Jean-Baptiste Lamark- Says that organisms gain
or lose traits based on the organisms selective
use of those traits over time.
Other Thoughts of Evolution
Charles
Lyell- Principles of Geology explains that
processes occurring now have shaped the
Earth’s geological features over long periods of
time.
Alfred Wallace- Writes to Darwin about evolution
by natural selection based on his study of plants
& animals