Transcript misconceptions

MISCONCEPTIONS
ABOUT DARWIN’S THEORY OF
EVOLUTION.
MISCONCEPTION - EVOLUTION IS A
THEORY ABOUT THE ORIGIN OF
LIFE.
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Evolutionary theory
focuses on how life
changed after its
origin. It looks at how
life branched and
diversified regardless
of how it started.
MISCONCEPTION – EVOLUTION IS LIKE A
CLIMB UP A LADDER OF PRGRESS;
ORGANISMS ARE ALWAYS GETTING BETTER
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Natural selection weeds out individuals that are less
successful in a particular environment, but this is always
linked to the environment, not to “getting better”
For evolution – an organism just has to be fit enough to
survive and reproduce in a particular environment.
MISCONCEPTION – EVOLUTION
MEANS THAT LIFE CHANGED BY
CHANCE.
 Mutation
is the ultimate source of variation
and mutation is random. However, natural
selection which acts on this variation, is
not a random process.
MISCONCEPTION – NATURAL
SELECTION INVOLVES ORGANISMS
“TRYING” TO ADAPT.

Natural selection acts
on genetic variation in
a population and
either an individual
has genes that are
good enough to
survive and
reproduce or it does
not. It can’t get the
right genes by “trying”
MISCONCEPTION – Natural Selection
gives organisms what they “need”.

Natural selection simply works on the
variation in a species. It cannot “sense” what
a species needs and direct the species.
NATURAL
SELECTION
IS AN EDITOR
MISCONCEPTION – Evolution is “just” a
theory
 Scientific
theories are based on evidence;
they allow us to make predictions and
have been tested in many ways.
 A theory in science is a well supported
explanation of some aspect of the natural
world.
MISCONCEPTION – Evolution is a
theory in crisis and is collapsing as
scientists lose confidence in it.
 Scientists
do not debate about whether
evolution took place, rather they argue
about how it took place.
Misconception – Gaps in the fossil
record disprove evolution.
biologists expect gaps – not
all transitional forms will be found (not all
organisms fossilise well and good fossilforming conditions are not always
common.
 Evolutionary
 Often,
transitional fossils have been
predicted although not present at the
time, and have subsequently been
discovered. Eg transitional organisms
between modern birds and their
theropod dinosaur ancestors and
between whales and their terrestrial
mammal ancestors.
Misconception – Evolutionary theory is
incomplete and is currently unable to
give a total explanation of life.
 Evolutionary
science is a work in
progress. Research continues to add
to our knowledge and recent
discoveries in molecular genetics
support the theory.
To date, evolution is the only well-supported
explanation for life’s diversity.
Misconception – the theory of
evolution is flawed, but scientists
won’t admit it.
 Scientists
keep their minds open to all
possibilities (as long as there is evidence)
and continue to refine the theory of
evolution.
Misconception: Evolution is not a
science because it is not
observable or testable.

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We cannot go back in time just as astronomers
cannot visit the stars or chemists look at atoms
but………..
Fossils give us snapshots of how organisms
change over time.
Studying modern organisms reveals examples
of evolution.
Artificial selection in dogs demonstrates
microevolution.
Lab experiments with fruitflies show the power of
mutation.
Misconception: most biologists
have rejected “Darwinism”
 Some
of Darwins ideas have been
modified eg the idea that evolution
proceeds at a slow gradual pace has
changed to accommodate the evidence
that sometimes evolution happens at a
relatively rapid pace.
 Darwins overall principles are still there –
just being added to.
And to think
that I didn’t
even know
about genetics
or mutations.
Misconception: evolution leads to
immoral behaviour – if children are
taught that they are animals, they
will behave like animals.
What do you think?
Misconception: Evolution and
Religion are incompatible.
 Evolution
(science) uses natural causes to
explain natural phenomena.
 Religion deals with beliefs that are beyond
the natural world.
 You
don’t have to choose between the two
– they are compatible.
Misconception: Teachers should
teach “both sides” and let students
decide for themselves.
is a scientific concept – creation
is a religious belief.
 Evolution
 Teaching
creationism alongside evolution
in science is like teaching that babies are
brought by the stork alongside
Reproduction in Human Biology!
 There is no scientific evidence to support
the stork theory – just as there is no
scientific evidence to support creation.