Download Natural selection - School

How many moths can you see on this slide?
Variation and Natural Selection
To describe how Variation drives natural
selection
To explain how Variation can lead to
extinction of less well adapted individuals.
Natural selection
• Within each species, the individuals with the
variations best suited to the environment will
survive better than the others.
• They will survive to reproduce.
• They pass on the genetic information for these
variations to their offspring.
• Species gradually evolve in this way. This
process is called natural selection.
Natural selection
TO COPY
Summary so far…
Variation drives Natural selection
• Variation exists between individuals of a
species
• Individuals in a species compete for
• Food , shelter, mates
• Those individuals who have better suited
variations survive, reproduce and pass their
genes on.
• Individuals who are less well adapted, die
Task! Card sort….
Your task!
• What colour are most polar bears? Why are they this colour?
• One in every 1000 births of polar bears has a mutation in the fur gene
which leads to it being born with brown fur. Explain what would happen
to this mutant polar bear.
• Imagine it is 100 years into the future and the polar ice caps have
melted. As a result there is little snow in the polar bear’s habitat. What
would happen to the white bears?
• Explain what would now happen to the mutant brown bears.
• What colour would most polar bears be now?
Polar Bears
iscolour
an example
of natural
selection:
1.This
What
are most polar
bears. Why
are they this colour?
2.Only
One in
every
1000 bears
births ofbest
polar bears
hasto
a mutation
the
polar
suited
their in the fur
gene which leads to it being born with brown fur. Explain what
environment
willbear.
survive to pass on
would happen to(adapted)
this mutant polar
their genes.
3. Imagine it is 100 years into the future and the polar ice caps
Because
of the
change
environment,
the
have melted.
As a result
therein
is the
little snow
in the polar bear’s
habitat.
Whathas
would
happen to the white bears?
polar
bear
evolved.
an animal
doesnow
not
evolve
it mutant
is at risk
ofbears.
4.If Explain
what would
happen
to the
brown
becoming extinct.
5. What colour would most polar bears be now?
Which side of the classroom would
you go?
Which side of the classroom would
you go?
Coral Snake
King Snake