Biodiversity: Genetic
Variation & Habitat Loss
Tuesday, January 26th, 2016
WHAT CAN WE DO? Eight Priorities for
Protecting Biodiversity
1. Take immediate action to preserve world’s biological hot
spots.
2. Keep intact remaining old growth.
3. Complete mapping of world’s biodiversity for inventory and
decision making.
4. Determine world’s marine hot spots.
5. Concentrate on protecting and restoring lake and river
systems (most threatened ecosystems).
6. Ensure that the full range of the earths
ecosystems are included in global conservation
strategy.
7. Make conservation profitable.
8. Initiate ecological restoration products to heal
some of the damage done and increase share of
earth’s land and water allotted to the rest of
nature.
Biodiversity Activity
D – Douglas Fir
N – Noble Fir
C – Western Red Cedar
M – Vine maples
H – Western Hemlock
L – Lodge pole Pine
WP – Western White Pine
B – Big leaf Maple
WD – Western Dogwood
WF – White Fir
Everyone's card should be D side face up. Go around
the room and 'meet' 3 different people. Write their
names on your piece of paper and return to your seat.
Monoculture vs Old Growth Forest
Biodiversity Activity
D – Douglas Fir
N – Noble Fir
C – Western Red Cedar
M – Vine maples
H – Western Hemlock
L – Lodge pole Pine
WP – Western White Pine
B – Big leaf Maple
WD – Western Dogwood
WF – White Fir
Flip your card over. Now, go around the room and
'meet' 3 different people again. Write their names on
your piece of paper and return to your seat.
Monoculture vs Old Growth Forest
Discuss with your group and in your notebook.... Answer these questions
1. What difference did you notice in the
number of trees that were infected with the
disease between the monoculture Douglas
Fir forest and the Old Growth Forest?
2. Why didn’t all the trees in the Old Growth
Forest get the disease?
3. In which type of forest would you need to
use more chemicals to control disease?
Why?
4. Which forest would you expect to have the
greater animal diversity? Why?
5. Currently logged forests are replanted with a single type
of tree (harvesting a single type of tree is easier, faster &
cheaper). If the variety of trees in a forest are cut down
and replanted with 1 type of tree, what will happen to
much of the wildlife that was adapted to that forest?
6. Many species can only live/reproduce in one type of
forest. The spotted owl is an example: it can only live
and successfully reproduce in old growth forests. If these
old growth forests are cut down, it’s unlikely this owl will
survive. Environmentalists call it an “indicator species.”
What does this mean? Why be concerned about one
species?
7. If you wanted to help wildlife, what would you do with
regards to the landscaping of your own home?
Genetic Biodiversity
Biological evolution by natural selection involves the
change in a population’s genetic makeup through
successive generations.
genetic variability
Mutations: random changes in the structure or number of
DNA molecules in a cell that can be inherited by offspring.
A population’s ability to adapt to new environmental
conditions through natural selection is limited by its
gene pool and how fast it can reproduce.
Humans have a relatively slow generation time (decades)
and output (# of young) versus some other species.
GEOLOGIC PROCESSES, CLIMATE CHANGE,
CATASTROPHES, AND EVOLUTION
The movement of tectonic plates, volcanic
eruptions, and earthquakes can wipe out existing
species and help form new ones.
The locations of continents and oceanic basins
influence climate.
The movement of continents have allowed species to
move.
Asteroids and meteorites hitting the earth and upheavals
of the earth from geologic processes have wiped out
large numbers of species and created evolutionary
opportunities by natural selection of new species.
SPECIATION, EXTINCTION,
AND BIODIVERSITY
Speciation: A new species can arise when
member of a population become isolated for a
long period of time.
Genetic makeup changes, preventing them from
producing fertile offspring with the original population
if reunited.
Geographic Isolation
…can lead to reproductive isolation,
divergence of gene pools and speciation.
HUMAN IMPACTS ON TERRESTRIAL BIODIVERSITY
Causes of Loss of Biodiversity: HIPPO
Habitat Loss: Greatest cause of decline & extinction
Primary cause – human development that removes
natural habitats
Alteration (deforestation, damming) has an effect as
well
Reduction in size of habitat can also lead to extinction
Supports smaller population, smaller population = less genetic
diversity
Decreases climatic options during periods of extreme
conditions
Increased interactions with harmful species
Lab: Habitat Fragmentation & Grizzly Bears
Important Vocabulary
Biodiversity
Species
Geographic range
Biomass
Corridors
Inbreeding
Round 1
Open Breeding Range
Round 2
Private Fence is built.
Do not cross the fence.
Round 3
Logging road is created.
Do not cross road or fence.
Round 4
Environmentalists lobby to
reopen bear habitats.
Open breeding range.
Round 5
Food is limited. Bears cannot
move more than 3 steps
Round 6
“Pear” bears are affected with a
disorder that makes them infertile.
Blue bears do not mate.
Round 7
Rainbow bears are unable to
adapt to climate change.
Red bears do not mate.
Round 8
Bears are in
the zoo. Bears
cannot
move.
Grizzly species biodiversity is reflected in the number
of different species of grizzlies in Yellowstone.
The geographic range of grizzly bears in Yellowstone
National Park is limited by the borders of the park.
The biomass of humans is greater than the biomass
of grizzly bear species in the wild.
The lack of corridors between Yellowstone National
Park and other grizzly habitats isolates the genes of
the grizzlies living within the park.
When the geographic range of a species is too
small, the chance of inbreeding is greater.