Download Plate Tectonics

Influence on Evolution & Biodiversity
Mrs. Page
ESS 2015-2016
 Explain how plate activity has influenced evolution and
biodiversity.
 Speciation through physical barriers
 Consequences of isolation for evolution
 Role of activity in generating new and diverse habitats (increasing
biodiversity)
• Earth’s Crust sits on top of a
convecting mantle
• The upper mantle
(asthenosphere) is moving do
to convection currents.
• This movement of the mantle
causes Earth’s crust to move
over time resulting in many of
the landforms and geographic
events that occur on Earth.
 Earth’s crust is
broken into large
pieces called plates
 Plates move over
time creating many
landforms &
geologic events
such as earthquakes
and volcanoes
 Because Earth’s plates are moving, the
continents have not always been in their
present location.
 Pangaea – large supercontinent
 As continents move apart – physical isolation
may occur
 Geologic events – volcanoes & earthquakes
can bring about loss of habitat and potential
loss of species
 Throughout history
there has been
several periods of
mass extinctions
 One theory: Possible
large volcanic
eruptions blocking
sunlight & destroying
habitats.
 Convergent: pushed together
 Divergent: moving apart
 Transform: sliding past
 What happens at plate
boundaries can be constructive:
building new land (ie: habitats) or
destructive; destroying land
 3 Scenarios:
 2 Continents Collide =
folded mountains
 Could lead to isolation –
mountain range separates
a population
 Creates new habitat
 Both constructive (building
mountain) and destructive
(one plate subducting)
Himalayas
Rocky
Mountains
 2 Oceanic Plates
Collide
 More dense plate
subducts
 Deep sea trench
 Oceanic Islands
 New Land formation =
new habitat
Aleutian Island Arc:
Possibility of future
land bridge?? Affect
on evolution &
biodiversity?
 1 Continental & 1
Oceanic Plate Collide
 Oceanic trench off
coastline (oceanic
plate subducts)
 Coastal Volcanic
Mountain Range
 Potential mass extinction
caused by large volcanic
eruptions
Cascade Mountain
Range – west coast
USA Pictured: Mt. St.
Helens
 Oceanic-oceanic
 Sea floor spreading
 Mid Ocean Ridge
 Continental-
continental
 Rift Valley
 Geographic
Isolation?
African Rift Valley
 Plates slide past with
friction
 EARTHQUAKE ZONES
Explain how plate tectonics has influenced
evolution and biodiversity. Give specific
examples.