Transcript Concept Survey: “Selection”

Concept Survey:
“Selection”
Please get out a piece of paper
In this task...
You will be shown a series of statements.
Read them carefully, then sort them into
one of two categories:
A = This an example of natural selection
B = Not an example of natural selection
Then explain your choice in writing.
Statement 1 of 3
Our little toes aren’t necessary for walking. Because of
this, some people think they will get smaller each
generation and eventually disappear from lack of use over
time.
A = This an example of natural selection
B = Not an example of natural selection
Explain your choice in writing.
Statement 2 of 3
Dark-colored grasshoppers resting on pale, dry grass
stalks are more easily seen by predators than lightcolored grasshoppers of the same species. Because the
dark-colored grasshoppers have higher mortality, there will
be fewer dark-colored grasshoppers each generation.
A = This an example of natural selection
B = Not an example of natural selection
Explain your choice in writing.
Statement 3 of 3
The flowering shrub called Hydrangea has flowers that are
blue if the shrub is growing in acidic soil. If the same shrub
is transplanted into alkaline soil, its blossoms will turn
pink.
A = This an example of natural selection
B = Not an example of natural selection
Explain your choice in writing.
Statement 4 of 7
The inheritable disorder called sickle-cell anemia occurs
at high rates in sub-Saharan Africa because people who
are carriers for the disease (that is, they have one sicklecell gene and one normal gene) resist the malaria parasite
better than people who do not carry the sickle-cell gene.
The disease occurs at much lower rates in parts of the
world where malaria is uncommon.
A = This an example of natural selection
B = Not an example of natural selection
Explain your choice in writing.
Statement 5 of 7
Dandelions growing in an unmowed field have leaves that
are upright. If the same field is mowed repeatedly, the
dandelions survive and grow new leaves, but the leaves
will grow flat against the ground.
A = This an example of natural selection
B = Not an example of natural selection
Explain your choice in writing.
Statement 6 of 7
Lactose intolerance (the inability to digest milk sugar) is common
worldwide. Mammals, including humans, normally stop digesting milk soon
after weaning. A small mutation causes people to continue making the milkdigesting enzyme all their lives. In prehistoric northern Europe, people
raised herd animals. In late winter, when food stores were depleted but herd
animals were giving birth, people with this mutation drank milk as an extra
food source. To this day, rates of lactose intolerance are very low in
northern Europe.
A = This an example of natural selection
B = Not an example of natural selection
Explain your choice in writing.
Statement 7 of 7
If domestic cats are abandoned in the wild, most of them
die within a few days, but some will have traits that help
them survive a while longer. If the survivors are fertile and
reproduce, and some of their offspring survive and
reproduce, several generations later the kittens that
descend from the original abandoned cats will be difficult
to tame even when captured early.
A = This an example of natural selection
B = Not an example of natural selection
Explain your choice in writing.
In groups…
Read each of these statements and decide if it is or is not an example of
Darwin’s theory of natural selection.
1.
2.
3.
Our little toes aren’t necessary for walking. Because of this, some people
think they will get smaller each generation and eventually disappear from
lack of use over time.
The flowering shrub called Hydrangea has flowers that are blue if the shrub
is growing in acidic soil. If the same shrub is transplanted into alkaline soil,
its blossoms will turn pink.
The inheritable disorder called sickle-cell anemia occurs at high rates in
sub-Saharan Africa because people who are carriers for the disease (that
is, they have one sickle-cell gene and one normal gene) resist the malaria
parasite better than people who do not carry the sickle-cell gene. The
disease occurs at much lower rates in parts of the world where malaria is
uncommon.