Transcript Ground Rules, exams, etc. (no “make up” exams) Text: read

Second Exam Thursday
Chapters 10, 11, 12, 13, 14, and 15 (most)
Can humans share spaceship earth?
Why Can't We Humans Share Spaceship Earth?
The Vanishing Book of Life on Earth
Watch Average Temperatures 1884-2012
Global Warming
Watch Domino Effects
Also Handouts 5, 6, and 7
Intelligent Design?
Space Travel
Agriculture
Economics
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Kc = 160
Kb = 125
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Nc* = 70
Nb* = 30
Nc* = Kc – acb Nb*
acb = (Kc – Nc*)/ Nb* = (160 – 70)/30 = 90/30 = 3.00
Nb* = Kb – abc Nc*
abc = (Kb – Nb*)/ Nc* = (125 – 30)/70 = 95/70 = 1.357
Experimental Ecology
Controls, replicates, treatments, pseudoreplication
Marine rocky intertidal, space-limited systems
Joe Connell, barnacles, Balanus and Chthamalus
Bob Paine, mindless experiments, Pisaster removal, keystone predator
Bruce Menge, removal + addition experiment with sea stars
Art Dunham, Big Bend Grapevine hills, lizard removal experiments
Jim Brown, New Mexico seed eating ants and rodents
2 replicates for each of 12 treatments
(including 11 manipulations plus 2 controls).
Short term: ants and rodents compete for seeds
Large seeded plants versus small seeded plants
Long term: indirect mutualism, facilitation between ants and rodents
Simberloff and Wilson’s defaunation experiments in Florida keys
Non-interactive, interactive, assortative, and evolutionary equilibria
Predation
Skutch’s naïve group selection perspective
Peregrine falcon and starling flocks
Frazzetta’s snake strike 3/100ths of a second
Holling’s preying mantids
Lotka-Volterra Predation Equations
“The recognition that animals can hold their rate of reproduction below
the maximum that is possible for them throws fresh light upon that
most hideous blot on the fair face of nature, predation, the killing and
devouring of one creature by another. It is well known that if predators
are suddenly removed, the animals on which they preyed may become
so numerous that they exhaust their food supply, with tragic consequences not only to themselves but to other associated animals. This
is particularly striking in the case of large herbivores which, in the
absence of checks upon their increase, may so overbrowse or overgraze
their range that, even after their removal it takes years to recover.
Hence predation is frequently regarded as a blessing in disguise,
necessary to preserve the health and balance of a natural community.
But, if animals can adjust their reproduction to the mortality of their
species, it follows that, if they were not subject to predation, they
would breed more slowly. The predators themselves, by creating a
need for more rapid multiplication, are responsible for the production
of the individuals that they slaughter. If predation had never arisen,”
“Predators would not be necessary to prevent overpopulation. Predation,
including its subtle form, parasitism, is a tragic miscarriage of evolution.
It is responsible for some of the worst passions that afflict that long
term predator, man, and through them for a large share of the evils
from which we suffer.*
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*I write in full awareness of the influence that the predatory habit in
all its manifold forms, itself a product of evolution, has had upon
subsequent evolution, speeding it up and increasing the diversity of
living creatures, many of which are far from admirable. However,
predation is only one of many selective agents, some of which, even
if acting more slowly, might have had more benign effects. I like to
think that on other planets, revolving around
distant stars, gentler methods have brought life
to fulfillment,and I would love to see the results.”
From A. F. Skutch, “A Naturalist in Costa Rica”
Predation and Parasitism
Predation and Parasitism
Adaptive Geometry of a Selfish Herd
(W. D. Hamilton)
“Adaptive Geometry of a Selfish Herd”
Thomas Frazzetta
400 Frames per second (3/100ths of a second)
C. S. Holling
C. S. Holling
Gause’s Predator-Prey Experiments
Georgi F. Gause
Gause’s Predator-Prey Experiments
Georgi F. Gause
Gause’s Predator-Prey Experiments
Georgi F. Gause
Industrial Melanism
Numbers of Typical and Melanic Marked Moths (Biston betularia)
Released and Recaptured in a Polluted Woods Near Birmingham and
an Unpolluted Woods Near Dorset*
__________________________________________________________
Polluted Woods
Unpolluted Woods
__________________________________________________________
Numbers of marked moths released
Typical
Melanic
64
154
496
473
Number of moths recaptured
Typical
16 (25%)
62 (12.5%)
Melanic
82 (53%)
30 (6.3%)
__________________________________________________________
* The wild population in the polluted woods was 87% melanic.
Source: From data of Kettlewell (1956).
Lotka-Volterra
Predation Equations
Alfred J. Lotka
coefficients of predation, p1 and p2
Vito Volterra
dN1 /dt = r1 N1 – p1 N1 N2
dN2 /dt = p2 N1 N2 – d2 N2
No self damping (no density dependence)
dN1 /dt = 0 when r1 = p1 N2 or N2 = r1 / p1
dN2 /dt = 0 when p2 N1 = d2 or N1 = d2 / p2
“Neutral
Stability”
Functional response = rate at which
Individual predators capture and eat
more prey per unit time as prey density
increases
C. S. Holling
Numerical response = increased
prey density raises the predator’s
population size and a greater
number of predators consume
An increased number of prey
Mike Rosenzweig
Robert MacArthur
Mike Rosenzweig
Robert MacArthur
<—Mike Rosenzweig
Robert MacArthur —>
Moderately efficient predator
Neutral stability — Vectors form a closed ellipse.
Amplitude of oscillations remains constant.
Robert MacArthur —>
Mike Rosenzweig
Unstable — extremely efficient predator
Vectors spiral outwards until a Limit Cycle is reached
Mike Rosenzweig
Robert MacArthur —>
Damped Oscillations — inefficient predator
Vectors spiral inwards to stable equilibrium point
“Prudent” Predation and Optimal Yield
Feeding territories
Consequence of senescence
Predator Escape Tactics
Aspect Diversity
Cryptic coloration (countershading)
Disruptive coloration
Flash coloration
Eyespots, head mimicry
Warning (aposematic) coloration
Alarm signals
Hawk alarm calls
Selfish callers
Plant secondary chemicals
Head Mimicry
Papilio caterpillar
Pit Viper caterpillar
DeVries Snake head
Selfish caller Hypotheses
1. Full up “I see you”
2. Mass pandemonium
3. Keep on moving
4. Mixed species flocks, fake alarm calls
<— Oogpister - Heliobolus lugubris