Monday, February 8, 2016 HOMEWORK: None
OBJECTIVE: I will be able to explain what a variation is and its
affects on a species by discussing the idea of selection pressure
DO NOW:Is variation important? Why or why not? Variation How does
variation affect survival?
How does variation affect reproduction? I will be able to explain
what a variation is and its affects on a species by discussion the
idea of selection pressure Example 1: Tadpoles and Dragonfly
Larvae
I will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Dragonfly
larvae Dragonfly larvae are the larvae stage of dragonflies. Here
is the life cycle of dragonflies. Dragonfly larvae eat many things,
including tadpoles. I will be able to explain what a variation is
and its affects on a species by discussion the idea of selection
pressure I will be able to explain what a variation is and its
affects on a species by discussion the idea of selection pressure
Experiment 12 pools, each with 10 tadpoles
Scientists measured many traits of the tadpoles, including: Body
Width Body Length Tail Muscle Width Color Total Length Then the
scientists released three dragonfly larvae into 8 of the pools.4 of
the pools did not have any dragonfly larvae (control). I will be
able to explain what a variation is and its affects on a species by
discussion the idea of selection pressure 12 Pools were set up.
Each with 10 tadpoles each
Experimental set up - Pond with 10 tadpoles = Dragonfly larva in
the pond Three dragonfly larva (predator) were released into 8 of
the 12 pools overnight 12 Pools were set up. Each with 10 tadpoles
each I will be able to explain what a variation is and its affects
on a species by discussion the idea of selection pressure Larvae in
Pond Overnight
I will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Predator Some
tadpoles in each pond were eaten by the dragonfly larvae overnight
I will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Tadpoles that
survived versus tadpoles that got eaten?
No predator pool Predator pool I will be able to explain what a
variation is and its affects on a species by discussion the idea of
selection pressure Experiment The next morning, they measured all
the same traits of the tadpoles again to see if the ones that
survived were different from the ones that got killed. I will be
able to explain what a variation is and its affects on a species by
discussion the idea of selection pressure Individually Answer
Question #3 in Packet
Individually, read and complete the following question. 3. Two
students were thinking about the tadpole study. George said, You
can see that all the tadpoles are practically the same.On average,
its a matter of luck as to which tadpoles get eaten and which
survive.So the tadpoles in the pools with the dragonfly larvae will
be about the same as the tadpoles in the pools without dragonfly
larvae. Prutha said, I dont agree.I think there will be some kind
of difference between the tadpoles. Who do you agree with more?
Explain your answer in detail. I will be able to explain what a
variation is and its affects on a species by discussion the idea of
selection pressure Results Compare the average measurements before
and after the tadpoles were left overnight in each of the pools.
Which average body measurements changed? What benefit does this
have to the tadpole population? No Predator Pool Body Measurements
AVERAGE measurement BEFORE left overnight AVERAGE measurement AFTER
left overnight Body Width 2.7 mm Body Length 4.1 mm Tail Muscle
Width 0.63 mm Total Length 11.5 mm Color Brown Predator Pool Body
Measurements AVERAGE measurement BEFORE left overnight AVERAGE
measurement AFTER left overnight Body Width 2.7 mm 2.3 mm Body
Length 4.1 mm Tail Muscle Width 0.63 mm 0.88 mm Total Length 11.5
mm Color Brown Predator Pool Body Measurements AVERAGE measurement
BEFORE left overnight AVERAGE measurement AFTER left overnight Body
Width 2.7 mm 2.3 mm Body Length 4.1 mm Tail Muscle Width 0.63 mm
0.88 mm Total Length 11.5 mm Color Brown No change Lower Higher
Results:
Body Measurements Change in population average in pools with no
predators overnight Change in population average in pools with
predators overnight Body Width No change Lower Color Tail Muscle
Width Higher Total Length Body Length What benefit does this have
to the tadpole population? I will be able to explain what a
variation is and its affects on a species by discussion the idea of
selection pressure Differences that look small can be very
important in survival.
I will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Rabbit species
in Australia
A heat spell in Australia put a lot of stress on mammals, including
rabbits.Many rabbits died. How might rabbits that survive differ
from rabbits that died during the heat wave? I will be able to
explain what a variation is and its affects on a species by
discussion the idea of selection pressure Do you see any
differences between this rabbit that survived and this rabbit that
died?
What variations do you think contributed to the survival of the one
rabbit and the death of the other? I will be able to explain what a
variation is and its affects on a species by discussion the idea of
selection pressure Rabbit species in Australia
The ears of rabbits that survived were slightly longer, on average.
Large ears help rabbits get rid of heat from their bodies. In a
heat spell, longer ears help rabbits stay cooler.Rabbits with
longer ears can often survive better. I will be able to explain
what a variation is and its affects on a species by discussion the
idea of selection pressure Differences that look small can be very
important in survival.
I will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Lekking Sage
Grouse I will be able to explain what a variation is and its
affects on a species by discussion the idea of selection pressure A
lek is an area where birds gather during the breeding season for
communitycourtship displaysto attract mates Males: The steps of the
display Strut are the same in every male Occur at dawn over a 3
month period Females: Visit a lek for 2-3 days before mating
Females choose a male to mate with I will be able to explain what a
variation is and its affects on a species by discussion the idea of
selection pressure Click on the link to see a sage grouse
display
https://www.youtube.com/watch?v=m0M8pZnNlnI I will be able to
explain what a variation is and its affects on a species by
discussion the idea of selection pressure What differences do you
see between the two males?
Female Male I will be able to explain what a variation is and its
affects on a species by discussion the idea of selection pressure
Did you notice a difference in the two males?
What was different about the male that the female picked? I will be
able to explain what a variation is and its affects on a species by
discussion the idea of selection pressure What did the scientists
find?
Males that attended more leks and had a higher display rate mated
with more females I will be able to explain what a variation is and
its affects on a species by discussion the idea of selection
pressure Differences that look small can be very important in
survival and reproduction.
I will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Anoles I will
be able to explain what a variation is and its affects on a species
by discussion the idea of selection pressure Anoles vary in their
hind limb length
Anoles vary in their hind limb length. Most anoles leg length fall
into the range of 14mm to 17mm I will be able to explain what a
variation is and its affects on a species by discussion the idea of
selection pressure I will be able to explain what a variation is
and its affects on a species by discussion the idea of selection
pressure Does it matter whether the legs are 15 mm long versus 17
mm long?
Why might it matter? I will be able to explain what a variation is
and its affects on a species by discussion the idea of selection
pressure Anoles with longer hind limbs are able to run faster on
trees with wide branches. Anoles with shorter hind limbs are able
to run faster on trees with narrow branches. I will be able to
explain what a variation is and its affects on a species by
discussion the idea of selection pressure So in an area with trees
with wide branches, which kind of anole has an advantage?
A: Anoles with longer hind limbs have a small advantage.They can
run faster from predators on the trees.Helps with survival. And in
an area with trees with narrow branches, which kind of anole has an
advantage? A.Anoles with shorter hind limbs have a small
advantage.They can run faster from predators on the trees, helps
with survival. So in a wood with trees with wide branches, anoles
with longer hind limbs have a small advantage. They run faster from
predators on the trees. A small difference in limb length helps
them survive better. But in a wood with trees with narrow branches,
anoles with shorter hind limbs have a small advantage. They run
faster from predators on the trees. A small difference in limb
length helps them survive better. I will be able to explain what a
variation is and its affects on a species by discussion the idea of
selection pressure Differences that look small can be very
important in survival.
I will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Grasshoppers I
will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure I will be able
to explain what a variation is and its affects on a species by
discussion the idea of selection pressure Experimental Setup 8
cages, each with 15 grasshoppers
Scientists measured many traits of the grasshoppers, including:
Length Weight Leg Length, etc. Then the scientists released three
praying mantids (predators) into each cage overnight They collected
all the grasshoppers that survived and measured them again I will
be able to explain what a variation is and its affects on a species
by discussion the idea of selection pressure Experimental Setup -
Cages with 15 Grasshoppers each They measured all the traits of all
the Grasshoppers. I will be able to explain what a variation is and
its affects on a species by discussion the idea of selection
pressure A single dragonfly larva (predator) was released into the
8 ponds.
Experimental Setup - Cages with 15 Grasshoppers each - Praying
Mantis in cage A single dragonfly larva (predator) was released
into the 8 ponds. They measured all the traits of all the
Grasshoppers. I will be able to explain what a variation is and its
affects on a species by discussion the idea of selection pressure
Cages overnight I will be able to explain what a variation is and
its affects on a species by discussion the idea of selection
pressure Not all Grasshoppers survive
I will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Individually
Answer Question #1 in Packet
Individually, read and complete the following question. 1. Two
students were thinking about the grasshopper study. Eric said, Its
clear.All the grasshoppers are just about the same in each
cage.Just by chance, some grasshoppers will be lucky and survive,
and others will be unlucky and get caught by the praying mantids.On
average, the grasshoppers that survive will be the same as the
grasshoppers that are eaten. Tara said, I dont agree.I think there
will be some kind of difference between the grasshoppers. Who do
you agree with more? Explain your answer in detail. Share answers I
will be able to explain what a variation is and its affects on a
species by discussion the idea of selection pressure Variation 2.
What variation(s) in traits might have been different between the
grasshoppers that died and the grasshoppers that survived? Closure
How does variation affect survival?
How does variation affect reproduction? I will be able to explain
what a variation is and its affects on a species by discussion the
idea of selection pressure