P1251328612NXfel

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A Story About Obesity and Nudity and the
Influence of Rivers on Colonies of Heterocephalus
glaber (An African Mole-Rat)
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The Naked Mole-Rat (Heterocephalus glaber)

• Eusocial, similar in behavior to hymenopterans
• (ants, bees, and wasps)
• Lives in large colonies of 80 individuals on
  average
• with a single dominant female breeder (queen)
  and
• her 1-3 mates
• Subterranean rodent, feeds on tubers. Rarely
  seen above
• ground.
• Distributed across eastern half of Kenya,
  Somalia, and
• the southeastern corner of Ethiopia

Size variance within and among colonies
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The study site in Meru and Kora National Park in
Kenya.
Meru
Meru

Kora
Kora
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Distribution of colonies that were sampled for
this study
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Legend
Elevation Map
Elevation (m)
-9,999
-9,998 - 0
0 - 200
201- 300
301 - 400
401 - 500
501 - 600
601 - 700
701 - 800
801 - 900
901 - 1,000
1,001 - 1,200
1,201 - 1,300
1,301 - 5,825

GTOPO30 Elevation http//edcdaac.usgs.gov/gtopo30
/e020n40.html
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Is average colony weight correlated with average
rainfall (elevation) across the study site?
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Is average colony weight correlated with average
rainfall (elevation) across the study site?
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Inverse Distance Squared Raster of Average Weight
Legend
Average Weight of 4 Heaviest Individuals (g)
23.2 - 36.2
36.3 - 39.7
39.8 - 45.4
45.5 - 53.8
53.9 - 83.5
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Correlogram Morans I test for spatial
autocorrelation of average colony weight
Average Lag Distance (m)
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Perhaps proximity to rivers is also correlated to
average colony weight
Legend
Average Weight of 4 Heaviest Individuals (g)
23.2 - 36.2
36.3 - 39.7
39.8 - 45.4
45.5 - 53.8
53.9 - 83.5
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Conclusion Elevation may explain 27 of the
average weight variation among
colonies Colonies are positively spatially
autocorrelated only within 5 km
distances Proximity to rivers may also be
correlated with average weight variation
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Are allele frequencies of these colonies
spatially autocorrelated?
A subterranean rodent is expected to have very
limited dispersal ability. Limited dispersal
translates to clustering of similar
allele frequencies.
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Distribution of an Allele Frequency of a
Microsatellite Locus
Legend
Allele Frequency
0
0.01 - 0.35
0.36 - 0.61
0.62 - 0.85
0.86 - 1.0
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Correlogram Morans I test for spatial
autocorrelation of allele frequecies among
colonies
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Rivers may again be influencing the pattern
Legend
Allele Frequency
0
0.01 - 0.35
0.36 - 0.61
0.62 - 0.85
0.86 - 1.0
River
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Future work Test whether rivers affect the
distribution of alleles at other microsatellite
loci in the same way. Test whether within a
river-bound region, alleles are
spatially autocorrelated. Test whether distance
from a river is correlated with average colony
weight.