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Second Exam ThursdayChapters 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
Kc = 160Kb = 125
Nc* = 70Nb* = 30
Nc* = Kc – cb Nb* cb = (Kc – Nc*)/ Nb* = (160 – 70)/30 = 90/30 = 3.00
Nb* = Kb – bc Nc* bc = (Kb – Nb*)/ Nc* = (125 – 30)/70 = 95/70 = 1.357
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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 belowthe maximum that is possible for them throws fresh light upon thatmost hideous blot on the fair face of nature, predation, the killing anddevouring of one creature by another. It is well known that if predatorsare suddenly removed, the animals on which they preyed may becomeso numerous that they exhaust their food supply, with tragic conse-quences not only to themselves but to other associated animals. Thisis particularly striking in the case of large herbivores which, in the absence of checks upon their increase, may so overbrowse or overgrazetheir 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 theirspecies, it follows that, if they were not subject to predation, they would breed more slowly. The predators themselves, by creating aneed for more rapid multiplication, are responsible for the productionof 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 longterm predator, man, and through them for a large share of the evilsfrom which we suffer.*————————————————————————————*I write in full awareness of the influence that the predatory habit inall its manifold forms, itself a product of evolution, has had uponsubsequent evolution, speeding it up and increasing the diversity ofliving creatures, many of which are far from admirable. However,predation is only one of many selective agents, some of which, evenif acting more slowly, might have had more benign effects. I like tothink 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”
400 Frames per second (3/100ths of a second)
Thomas Frazzetta
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 64 496Melanic 154 473
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
coefficients of predation, p1 and p2
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
Alfred J. Lotka Vito Volterra
“NeutralStability”
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’spopulation size and a greater number of predators consume An increased number of prey
Mike Rosenzweig
Robert MacArthur
Mike Rosenzweig
Robert MacArthur
Moderately efficient predatorNeutral stability — Vectors form a closed ellipse. Amplitude of oscillations remains constant.
<—Mike Rosenzweig Robert MacArthur —>
Unstable — extremely efficient predatorVectors spiral outwards until a Limit Cycle is reached
Mike Rosenzweig
Robert MacArthur —>
Damped Oscillations — inefficient predatorVectors spiral inwards to stable equilibrium point
Mike RosenzweigRobert MacArthur —>
“Prudent” Predation and Optimal Yield
Feeding territories
Consequence of senescence
Predator Escape TacticsAspect DiversityCryptic coloration (countershading)Disruptive colorationFlash colorationEyespots, head mimicryWarning (aposematic) coloration Alarm signalsHawk alarm callsSelfish callersPlant 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