Download evolution 2 - Hicksville Public Schools

Aim: How does adaptative
variation lead to the
survival of an organism?
How is Kevin Costner different
form everybody else in Water
World?
He had webbed feet and gills
ADAPTIVE VARIATION
Variation
DIFFERENCES (in structure and or
behavior) within a population
What produces variations?
• Sexual reproduction
recombination of
genes
• Meiosis
• Crossing over
• Independent
assortment –
different gametes
made by one parent
• Mutations
Why are variations important to
a population?
• Variation in a species
increases the chances
that some members
will survive an
environmental
change.
• Why is this important?
For example: The peppered
moth
Adaptation
A variation that allows an organism to
survive in it’s environment
Adaptive Variation
A variation that
allows you to
survive a
changing
environment
What would happen to a
population with variation if
the environment changed?
• Those who had
an adaptive
variation would
survive. Those
that don’t will
die. This would
lead to ….
EVOLUTION
What would happen to a
population that did not have
variation?
• If they don’t posses
a trait that allows
them to adapt to a
changing
environment, they
will die out:
EXTINCTION
What is the theory of evolution?
•
Theory – well tested
conclusion that has
been accepted by the
scientific community.
• Evolution :
1) The process by which
species change over
time.
2) Present day species
are related to ancient
species.
Summary Questions:
1) The driving force behind evolution is the
interaction between the individual organisms and
the __________.
2) In your own words, define what an adaptive
variation is?
3) Explain what the following statement means,
“Individual organisms do not evolve, species do”.
A certain species has little genetic variation.
The rapid extinction of this species would
most likely result from the effect of
(1) successful cloning
(2) gene manipulation
(3) environmental change
(4) genetic recombination
The least genetic variation will probably be
found in the offspring of organisms that
reproduce using
(1) mitosis to produce a larger population
(2) meiosis to produce gametes
(3) fusion of eggs and sperm to produce
zygotes
(4) internal fertilization to produce an
embryo
In an environment that undergoes frequent
change, species that reproduce sexually may
have an advantage over species that reproduce
asexually because the sexually reproducing
species produce
(1) more offspring in each generation
(2) identical offspring
(3) offspring with more variety
(4) new species of offspring in each generation
In a group of mushrooms exposed to a poisonous
chemical, only a few of the mushrooms survived.
The best explanation for the resistance of the
surviving mushrooms is that the resistance
(1) was transmitted to the mushrooms from the
poisonous chemical
(2) resulted from the presence of mutations in
the mushrooms
(3) was transferred through the food web to the
mushrooms
(4) developed in response to the poisonous
chemical