Download Evolutionary Theory

Evolutionary Theory
This pygmy sea horse is
smaller than your
fingernail. It lives
exclusively among
certain kinds of coral in
coral reefs of the western
Pacific Ocean.
Charles Darwin’s theory
of evolution by natural
selection provides an
explanation for how
characteristics such as
camouflage can arise
over time.
His theory continues to
be supported and
explained by scientists.
Key Ideas
• Why is evolutionary theory associated with
Charles Darwin?
• How was Darwin influenced by his
personal experiences?
• How was Darwin influenced by the ideas
of others?
• How is the scientific explanation for
evolution different from other
explanations?
What is Evolution?
Tiktaalik is a genus of extinct lobefinned fish from the late Devonian
period, with many features akin to
those of tetrapods (four-legged
animals). Fossil found in 2004.
• Evolution is the
process of change by
which new species
develop from
preexisting species
over time.
• First, however, we will
examine some myths
associated with the
study of evolution.
Myths About Evolution #1
• Charles Darwin
developed the theory
of evolution
Debunked!
• The theory of evolution
existed well before
Darwin.
• He was not the only
scientist who proposed
explanations for changes
in time. Others included:
Erasmus Darwin, Jean
Baptiste Lamarck, and
Alfred Wallace.
Modern evolutionary theory began
when Darwin presented evidence that
evolution happens and offered an
explanation of how it happens.
Myth #2
• Living things adapt to
their environment.
Debunked!
• Living things are
adapted to their
environments (that’s
why they are alive).
• Individuals are
unchanging; they live
or die based on the
traits they are born
with.
• They cannot adapt
during their lifetime.
Myth #3
• Biologists “believe” in
evolution.
Nicholas E. Federoff
Wildlife Biologist
Debunked!
• Science is not based
on belief.
• The theory of
evolution provides an
evidence-based
model explaining the
relationship between
organisms and their
environment.
Myth # 4
• Monkeys will
eventually become
human.
Debunked!
• There are many
species of primates
and all are adapted to
their environments.
• A chimpanzee would
not turn into a human
any more likely than a
cheetah would
become a lion—they
are different species.
Myth # 5
• Evolution is JUST a
theory.
Debunked!
• Saying “just” a theory
implies that it is a
guess.
• Scientific theories are
based on much
evidence.
• A theory in science is
a broad explanation
that has been
scientifically tested
and supported.
Peppered Moths
Myth #6
• Only atheists accept
the Theory of
Evolution by Natural
Selection
Debunked!
• Scientists of many
religions around the
world accept
evolution to be true
and do not find it
incompatible with
their faith.
Myth # 7
• No one has ever seen
evolution happen.
Debunked!
• In organisms that
reproduce quickly (like
bacteria), changes can be
directly observed. For
example, resistance to
antibiotics is evolution in
action!
• Many other studies have
been done, including
important research using
insects, birds, and fish.
Myth # 8
• Order cannot come
from disorder so
evolution is false.
Debunked!
• Many instances in
nature show
processes in which
molecules and
substances organize.
• These processes
require energy—the
sun provides the
energy that ultimately
fuels almost all life
processes.
Myth # 9
• Scientists regularly
debate whether
evolution occurs.
Debunked!
• There is no debate among
scientists about whether
evolution has occurred.
• Scientists debate some of
the processes of evolution or
the relationship between
current organisms and
fossils.
• The only place the evolution
debate continues is in social
circles.
Myth # 10
• There are no
transition fossils.
Pleisaur found in
California.
Debunked!
• Museums are filled
with fossils that show
intermediate species.
Myth # 11
• Carbon
dating is
not
accurate;
therefore
the
scientific
age of the
earth is
inaccurate.
Debunked!
• Carbon dating is only one
of many methods used to
determine the age of the
earth.
• Other elements such as
Argon and Potassium
provide more evidence of
the age of the earth and
rock formations.
• Taken as a whole, the
evidence is overwhelming
that the earth is very old
(4.5 billion years).