Download Biogeography and Zoogeography

Lecture 5
Biogeography and Zoogeography
&
Guest Presentation by
Dr. Kris Hundertmark
Sept. 22, 2010
1
Biogeography = The study of the
patterns of distribution of organisms,
including both extant and extinct
species.
Zoogeography = The study of these
distributions in animals, including
mammals
Sept. 22, 2010
2
Sept. 22, 2010
Why are marsupials in only in
Australia and the Americas?
3
Why aren’t non-human primates in North America?
Or maybe they are?
Sept. 22, 2010
4
How has an individual species distribution changed, and
why?
Sept. 22, 2010
5
Categories of Biogeography
• Historical biogeography
– emphasizes the study
of changes in species
ranges that have taken
place over evolutionay
time.
Sept. 22, 2010
• Ecological biogeography
– spatial investigation of
current distributions
and seeks to explain
that interaction in terms
of community-level
interactions.
6
Distribution of Rangifer tarandus
CIRCUMBOREAL
AND
CIRCUMPOLAR
Sept. 22, 2010
7
Historical biogeography
• Endemism – restriction of a species range to a
circumscribed area.
Sept. 22, 2010
8
Southeast Alaska
Sept. 22, 2010
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Faunal Regions
Based on geographic barriers, geological history, and mammal distribution
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10
Plate tectonics & Continental drift
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11
Sept. 22, 2010
12
Palearctic
Families = 42
Endemics = 0
Most species diversity is in the warm
wet areas which the palearctic
shares with the Ethiopean and
Oriental.
Bering land bridge? 50% of the
species in P are in Nearctic
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13
Nearctic
Families = 37
Endemics = 2
Antilocapridae
Sept. 22, 2010
Aplodontidae
14
Neotropical
Families = 50
Endemics = 22
Sept. 22, 2010
15
Ethiopian
Families = 52
Endemics = 20
Sept. 22, 2010
16
Oriental
Families = 50
Endemics = 5
Colugos, tree shrews, hog-nosed bats, gibbons, and tarsiers
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17
Australian
Families = 28
Endemics = 20 (71%)
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18
Oceanic
Mammals that live on islands
remote from continents and
those that are fully marine
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Abiotic Processes
Continental Drift
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20
Abiotic
Processes
Ice Ages
Sept. 22, 2010
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Abiotic Processes
Less Severe Climate Change Still Matters
• Tipping points – a change of just a few degrees changes everything
Sept. 22, 2010
22
Biotic Processes
• Dispersal – can increase species richness
– Ecological dispersal
• An individual moving from its natal area to breed
elsewhere.
– Species dispersal (biogeographic term)
• Passive – hitches a ride
• Active – species move by there own locomotion
Sept. 22, 2010
23
Biotic processes
• Extinction (global) or Extirpation
(local) = reduces species richness
– Background – incidental loss due to local
factors (habitat change, competition,
predation).
– Mass extinction – catastrophic event
Sept. 22, 2010
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Local extirpations
• http://www.youtube.com/watch?v=I9skxcC2
MYg
• http://www.wolfsongalaska.org/news/Alaska_
current_events_205.htm
Sept. 22, 2010
25
Ecogeographic Patterns
•
•
•
•
•
•
Island Rule
Rapoport’s Rule
Bergmann’s Rule
Allen’s Rule
Gloger’s Rule
Other Patterns
– Latitudinal and Elevation Gradients
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26
The term “RULE” is used in
the loosest sense. There
are exceptions in every
case and these “RULES”
often overgeneralize.
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27
Island rules
• Small mammals are bigger (insular gigantism)
• Larger mammals are smaller (insular
dwarfism)
• If food is scarce and you're small, for example,
getting bigger can help you travel farther for
food and survive longer without eating. If food
is scarce and you're large, on the other hand,
getting smaller can help you survive on less
food.
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Rapoport’s Rule
• Species ranges in mammals tends to increase
from the equator to the poles
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Bergmann’s Rule
• Body size increases with latitude
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30
Allen’s rule
• Animals in colder climates have shorter
appendages than their close relatives in
warmer climates.
– Endothermy?
– Overgeneralized?
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31
Gloger’s rule
• Mammals with darker colored pelage are in
more humid environments.
– Humidity?
– Snow, ice, and sand
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Latitudinal
• Species diversity decreases with increasing
latitude.
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Elevation
• Decrease in species diversity with increase in
elevation.
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