First Exam Thursday 18 February
Covers Chapters 1-4, 6-7plus Chapter 16 and first 8 lectures, 5
discussions, plus 8 Readings: Scientific Methods Natural Selection
Human Nature Our Hunter-Gatherer Heritage Evolution of Uncaring
Humanoids Unburnable Oil Population Growth Evolutions Problem
Gamblers Principle of Allocation
Tolerance Curves Ray Huey Principle of Allocation Principle of
Allocation
Tolerance Curves Ray Huey Principle of Allocation Principle of
Allocation
Tolerance Curves Ray Huey Principle of Allocation Performance
plotted against temperature
Acclimation Performance plotted against temperature Hypothetical
response curves showinginteractions Resource Budgets Principle of
Allocation
Time, Matter, and Energy Budgets Rock Pipits Anthus spinoletta Mild
Winter versus Harsh Winter Feeding: 6.5 hours vs hours Resting:
1.75 hours vs. 0.6 hours Fighting: 0.75 hours vs. 0.1 hour Leaf
Tactics Light Water availability Prevailing winds Herbivores
Costs and Profits of Leaf Size, Shape, and Placement Leaf Tactics
Similar types of leaves have evolved independently in different
plant lineages subjected to comparable climatic conditions Compound
leaves conserve woody tissue Small leaflets in hot dry regions, but
larger under warm moist conditions Shade tolerant understory
species usually have larger and less lobed leaves than canopy
species Lobed leaves do not cast as dense and solid a shadow as do
leaves with continuous margins In lowland wet tropical rainforest,
trees tend to have large evergreen leaves
In chaparral, plants tend to have small sclerophyllous evergreen
leaves Arid regions tend to support leafless stem succulents such
as cacti or plants with entire leaf margins Cold wet climates tend
to support plants with notched or lobed leaf margins Adaptive
Geometry Evergreen vs
Adaptive Geometry Evergreen vs. Deciduous Monolayered vs
Multilayered plants Shade Tolerance Plant Life Forms Evergreen
vs
Plant Life Forms Evergreen vs. Deciduous Monolayered vs
Multilayered plants Shade Tolerance Xerophytic vs. Mesophytic
leaves Also Hydrophytes (water lilies) Gordon Orians Otto Solbrig
Plant Life Forms Evergreen vs
Plant Life Forms Evergreen vs. Deciduous Monolayered vs
Multilayered plants Shade Tolerance Xerophytic vs. Mesophytic
leaves Also Hydrophytes (water lilies)Creosote Bush Larrea
divaricata-- Mesquite Prosopis Foraging Tactics and Feeding
EfficiencyCosts and Profits of ForagingAn optimal foraging tactic
maximizes the difference between foraging profits and their
costsFood = matter and energy for maintenance and reproduction
Hazards: exposure topredators, loss of time for other
activitiesSit-and-Wait ambush predators(e.g. spiders at webs)
Widely foraging active hunters (go out and find prey)Search Time
(per item eaten) versus Pursuit Time (per item eaten) Search for
all possible preyitems, but pursue them one at a time Preyitems can
be ranked from most preferred to least desirable Economics of
Consumer ChoiceAssumptions:a) Environmental structure is
repeatable, withstatistical expectation of finding a given
resource(habitat, microhabitat, or prey item)b) Food items can be
arranged along a continuous spectrum, such as by size or energy
rewardc) Similar phenotypes are closely equivalent in harvesting
abilitiesd) Principle of Allocation applies: no one phenotype can
be maximally efficient on all prey typese) An individuals economic
goal is to maximize its total intake of food resources Robert
MacArthur Economics of Consumer Choice Four Phases of
Foraging:
Economics of Consumer Choice Four Phases of Foraging:1) deciding
where to search2) searching for palatable food items3) upon
locating a potential food item,deciding whether or not to pursue
it4) pursuit itself, with possible capture and eatingSearch and
pursuit efficiencies for each food type in each habitat are
entirelydetermined bypreceding assumptions about morphology and
environmental repeatability.These efficiencies dictate
probabilities associated with search and pursuit (phases2 and 4)
.Thus, need to consider only the two decisions: where to forage and
which prey items to pursue (phases 1 and 3above) Robert MacArthur
Economics of Consumer Choice (R. H
Economics of Consumer Choice(R. H. MacArthur)Clearly, an optimal
consumer should forage where its expectation of yield is greatest
an easy decision to make, given knowledgeof efficiency
probabilities and the structure of the environment (of course, in
reality, animals are not omniscient and must makedecisions based on
incomplete information).The decision as to which prey items to
pursue is also simple.Upon finding a potential prey item, a
consumer has just twooptions: either pursue it or goon searching
for a better itemand pursue that one instead.Both decisions end in
the foragerbeginning a new search, so the best choice is clearly
the one thatreturns the greatest yield per unit time.An optimal
consumer should opt to pursue an item only when itcannot expect to
locate, catch and eat a better item during the time required
tocapture and ingest the first prey item. From Huey and Pianka 1981
Ecology 62: 991-999. C. S. Holling 400 Frames per second (3/100ths
of a second)
Tom Frazzetta Thomas Frazzetta 400 Frames per second(3/100ths of a
second) Physiological EcologyHomeostasis: maintenance of a
relatively stable internal state under a much wider range of
external environmental conditionsTemperature regulation
(thermoregulation)Physiological Optima and Tolerance
CurvesAcclimation Energetics of Metabolism and Movement Ingestion =
Assimilation + Egestion Assimilation = Productivity + Respiration
Productivity = Growth + ReproductionIngestion =Egestion +
{Respiration + Growth + Reproduction} {Assimilation} Homeotherm
versus Poikilotherm Endotherm versus Ectotherm Body Mass, grams
Log, Metabolic Cost of Movement
Log, Log, Metabolic Cost of Movement
Log, Log, Metabolic Cost of Movement
Log, Log, Adaptation and Deterioration of Environment
Ronald A. Fisher Non-directed (random) changes in either Aor Bare
equally likely to reduce the level of adaptation (d ) when small,
but as the magnitude of undirected change increases, the
probability of improvement diminishes. Duality of Fishers model (A
and B can be interchanged) Water Economy in Desert Organisms Other
Limiting Materials Sensory Capacities and Environmental Cues
Adaptive Suites Design Constraints Heat Budgets and Thermal
Ecology
