Patterns of species diversity

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Patterns of species diversity
Biogeography
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SPECIES DIVERSITY
Alpha diversity Number of species in a local,
homogeneous habitat
Beta diversity rate of species change across
local habitat types
Gamma diversity diversity within a
region
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AREA DIVERSITY
SPECIES-AREA RULE A universal pattern of
increasing species diversity with increasing
area
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PATTERNS OF SPECIES DIVERSITY
North American mammal faunal provinces (1876)
J. A. Allen 1838 - 1921
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LIFE ZONE CONCEPT (1890)
C. Hart Merriam 1855-1942
San Francisco Peak, Arizona
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Elevation gradients ecological diversity
Windward
Leeward
Mesic
Xeric
As air decends, it picks up moisture creating a
rain shadow
Adiabatic Lapse Air cools as it rises (ca. 10
C / 1000 m)
Ability of air to hold Water declines as it
Cools causing precipitation
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Merriams North American Life Zones
Similarity of patterns across gradients of
elevation and latitude
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Biome concept (1939)
Frederick Clements 1874-1945
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Latitude and diversity -- N S America
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Latitude and diversity
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Elevation gradients -- Temperate vs. Tropical
Local biotic communities
Great seasonality Boundaries poorly defined
Mt. Whitney (4417 m) California, USA
Little seasonality Boundaries well defined
Mt. Kinabalu (4101 m) Sabah (Borneo) Malaysia
IN TROPICS
Geographic barriers to dispersal are more
profound
Communities are stable over LONG time periods
Finer niche partitioning Higher rates of
speciation
All measures of biodiversity are higher in the
tropics
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Biogeography Global Patterns
Journal of Researches (1839)
On the Origin of Species by Means of Natural
Selection (1859)
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Biogeography Global Patterns
The Geographic Distribution of Animals (1876)
Alfred R. Wallace 1823-1913
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Biogeography early limitations
Defining boundaries between faunal regions
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Biogeography early limitations
Defining boundaries between faunal regions
Wallaces Line
Oriental region
Australian region
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Biogeography early limitations
Defining boundaries between faunal regions
Wallaces Line
Imperfect knowledge of geography
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Biogeography early limitations
Defining boundaries between faunal regions
Oriental region
Wallacea
Continental shelf margins define the limits of
Pleistocene land bridges and the extent of major
faunal regions
Region of mixed oceanic faunas derived from
both Oriental and Australian regions
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Biogeography early limitations
Difficulties in explaining certain distribution
patterns...
X X
X
X
Marsupials
Hystricognath rodents and Anthropoid primates
Faunal similarity of northern continents
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Biogeography early limitations
Assumption of continental stasis
X X
X
X
Solution past land-bridges to allow faunal
mixing
Collective area of all proposed land-bridges
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Continental Drift (1920)
Alfred Wegener 1880-1930
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Continental Drift
Past (65 mya)
Present
Future (50 my)
Connection of Australia with SE Asia
Greater separation across Atlantic
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American faunal interchange
Late Miocene (ca. 10-8 mya)
Series of islands filter bridge
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American faunal interchange
Late Pliocene (ca. 4-2 mya)
Initial formation of Isthmus
EXTINCTIONS Marsupial carnivores Endemic
ungulates
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American faunal interchange
Pleistocene (1.8 m 10,000 ya)
Repeated connection during glacial cycles
EXTINCTIONS Endemic ungulates
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American faunal interchange
Holocene (lt 10,000 ya)
Anteaters Tree sloths SA rodents
Most recent exchanges
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Asian - American interchange
Late Pliocene (ca. 4-2 mya)
Horses Camels Cheetahs
Bears Lynx Saber-tooth cats
Repeated connection via ice-free corridors during
glacial cycles
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Asian - American interchange
Early to mid-Pleistocene (1.8 - 0.5 mya)
Jaguar Elephants Caribou Wolf
Lemmings
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Asian - American interchange
Late Pleistocene (ca. 20,000 ya)
Moose Muskox Bison Fox Lion
Humans
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Pleistocene overkill Extinction and faunal
collapse through human hunting (1967)
Paul S. Martin b 1928
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North American Pleistocene mammal
extinctions (by family)
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Pleistocene extinctions
North American extinction pattern
Global extinction pattern
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Phylogeography
Congruence between geography and phylogeny
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Phylogeography recurrent patterns in
multiple taxa
From B. Arbogast G.J. Kenagy. 2001. J.
Biogeograpy 28819-825
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Island Biogeography
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Island Biogeography
The theory of island biogeography (1967) Equili
brium theory
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Island Biogeography
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BIODIVERSITY COMPARISONS
Area (km2) 212,815
298,170
Native mammals 134
190
Endemic mammals 1
7
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PHILIPPINE GEOLOGY
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PHILIPPINE GEOLOGY
FROM Hall, R. 1998. The plate tectonics of SE
Asia and the distribution of land and sea.
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PLEISTOCENE GEOGRAPHY
Maximum glacial extent, ca. 18,000 years ago
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Philippines Pleistocene island dynamics
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Philippines elevation and diversity
Mindanao
Luzon
Isolated highlands are separate centers of
local endemism
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Phylogeography Philippine rodents (genus
Apomys) Steppan et al. 2003. Biol. J. Linn.
Soc. 80699-715
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Phylogeography Philippine rodents (genus
Apomys) Steppan et al. 2003. Biol. J. Linn.
Soc. 80699-715
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Phylogeography Philippine rodents (genus
Apomys) Steppan et al. 2003. Biol. J. Linn.
Soc. 80699-715
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Phylogeography Philippine rodents (genus
Apomys) Steppan et al. 2003. Biol. J. Linn.
Soc. 80699-715
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Phylogeography Philippine rodents (genus
Apomys) Steppan et al. 2003. Biol. J. Linn.
Soc. 80699-715