1. Effects of agriculture on evolution of native species
Scott A. Chamberlain1, Kenneth D. Whitney2, and Jennifer A. Rudgers2
1 Simon Fraser University, Canada – 2 Rice University, USA = the take-home message
The Idea What did we find? …what did we find?
• Agriculture covers ~50% of vegetated land surface Does proximity to sunflower crops alter: Does proximity to sunflower crops alter:
• Evolution is altered in agricultural landscapes 1. …abundance of mutualists and antagonists? 4. …contribution of mutualists and antagonists to
– Gene flow occurs from crops to wild relative plants Mutualists more abundant near, antagonists more selection on native plant floral traits?
– Evolution of resistance occurs in plants to GMOs abundant far from crops
Changes in mutualist/antagonist communities drive
– Evolution of plants/insects to herbicides/pesticides Results
Predictions differences in selection near vs. far from crops
• Yet, we know less of how natural selection is altered Far
Near
Visits inflorescence-1
in agricultural landscapes through species interactions Floral
traits
Inflor.
traits
Floral
traits
Inflor.
traits
• There is much evidence for altered biotic communities
Abundance
min-1
• How do changes in abundance and community structure Site
1
-­‐0.06
0.004
of mutualists and antagonists near sunflower crops Far Near 2011
Iso
sp.
N.
hel.
Pollen
Iso
sp.
N.
hel.
Pollen
alter natural selection on flower traits in wild
N. Helianthi abundance
sunflowers?
Fitness
Fitness
Abundance
The Questions Far Near
Floral
traits
Inflor.
traits
Floral
traits
Inflor.
traits
Does proximity to crops alter: Site
2
2011
1. Abundance of mutualists and antagonists? 2. …community structure of mutualists and antagonists? 0.002
Iso
sp.
N.
hel.
Pollen
-­‐0.01
Iso
sp.
N.
hel.
Pollen
2. Community structure of mutualists and antagonists? Beta-diversity of mutualists greater near crops
3. Selection on native plant floral traits? Fitness
Fitness
Predictions Results
4. Contribution of mutualists and antagonists to
selection on native plant floral traits? What does it mean?
Conclusions
• Sunflower mutualists more abundant near,
The Approach antagonists more abundant far from crops
Natural habitat • Beta-diversity of mutualists greater near crops
Agricultural Other Crop • Natural selection altered by proximity to sunflower
landscape [corn/sorghum/
wheat/cotton]
crops
Distance Far No difference for antagonists • Changes in mutualist/antagonist communities drive
~ 2.5 km
differences in selection near vs. far from crops
• This is one of few studies to show agricultural
3. …selection on native plant floral traits? effects on natural selection across a landscape in a
Sunflower Crop native plant species
Natural selection altered by proximity to sunflower crops,
Distance
and more variable near sunflower crops
Near ≤ 10 m
Implications
Proximity to sunflowers (2 levels)
• Mutualist-antagonist framework may be useful in
X understanding agricultural effects on plant evolution
Seed source (2 levels) • Natural selection altered in agricultural landscapes,
@ 5 sites in ‘10, @ 2 sites in ‘11 BUT contrary to expectation
Silhouettes from phylopic.org
Data Collected
• Pollinators: pollinator observations Scott Chamberlain
• Seed predators: counted damaged seeds scott.sfu@gmail.com t: @recology_
• Folivores: leaf damage http://schamberlain.github.com/scott