Ecology, Biology 216 Todd Livdahl Requirements



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Ecology, Biology 216

  • Todd Livdahl

Requirements

  • Essays (3) 20%
  • Lab exercises 20%
  • Quizzes (3) 30%
  • Final Exam (comp) 20%

Essays

Lab Exercises

  • Interpret ecological data
  • Clarify relationship between field observations and central concepts
  • Develop skills in computation and analysis

Quizzes and Final

  • 3 Quizzes, equal weight
  • Full class in length
  • Concept-driven
  • Qualitative

Substitution

  • Final = 2 x (quiz)
  • If Final/2 > (lowest quiz), then Final/2 will be substituted for the lowest quiz score
  • Example: Quizzes-- 25 27 19 (out of 30)
  • Final-- 44 (out of 60), 44/2 > 19
  • lowest quiz score (19) is replaced by (22)
  • NO MAKEUP QUIZZES

First Essay

  • Due Jan. 28
  • Description of problem
  • Justification as a problem
  • Solution strategies possible or solution strategies attempted
  • Problems arising from solutions
  • 3-4 pages should suffice

Borneo

  • Mosquitoes
  • Malaria
  • Caterpillars
  • Roof Thatching
  • Wasps

The Borneo Cat Crisis

  • Housefly control
  • Houseflies
  • Geckos
  • Cats
  • Rats

The Coconut Leaf-mining Beetle Crisis, Fiji

  • 1850-1880 Early development, plantations
  • 1880-1900 Intensive cultivation and shipping
  • 1900-1920 Gradual increase in impact of beetle
  • 1920 Outbreaks threaten Fiji economy

Natural Coconut Community

  • Coconut
  • Beetle:
  • Egg
  • Larva
  • Pupa
  • Adult
  • Ants
  • Mite 1
  • Ants
  • Lizards
  • Birds
  • Mite 2
  • Mite 3
  • Mite 4

Intensive Cultivation:

  • Coconut
  • Beetle:
  • Egg
  • Larva
  • Pupa
  • Adult
  • Ants
  • Mite 1
  • Ants
  • Lizards
  • Birds
  • Mite 2
  • Mite 3
  • Mite 4
  • Mite 5

Container-breeding Mosquitoes

  • Adults
  • Eggs
  • Larvae
  • Pupae
  • Container habitat

Container Habitats

  • Natural examples
  • Treeholes
  • Bromeliads
  • Pitcher plants
  • Bamboo stems
  • Leaf axils
  • Crab holes
  • Snail shells
  • Snow-melt pools
  • Water-filled hoof prints
  • Domestic examples (short list)
  • Bird baths
  • Cemetery urns
  • Discarded junk
  • Bottle caps to Bath tubs
  • Downspouts, eave troughs
  • Cisterns
  • Trash barrels
  • Tires

Meetings of interest (from AMCA Newsletter):

Aedes albopictus and the New Globalism

  • Distribution:
  • 1983: tropical and temperate Asia, Pacific Islands
  • 1984, 1985: Memphis, Tennessee
  • Houston, Texas-- the most abundant mosquito in a pile of used tires
  • First discovery of Aedes albopictus in Western Hemisphere

Aedes albopictus since 1985

  • Numerous US localities
  • South America, esp. Brazil
  • Central America, Mexico
  • Europe (Italy, Albania)
  • Caribbean
  • Bermuda
  • Used Tire Importation
  • 1985
  • 1980
  • 1975
  • 1970
  • 0
  • 1
  • 2
  • 3
  • From countries in the range of albopictus
  • From countries outside albopictus range
  • Year
  • Used Tires Imported (millions)

Potential Habitats

Potential Habitats

Treehole

Long-range Prospects for Invasion

  • Depend on:
  • Adaptations to physical challenges
  • Success in dealing with native community
  • Competition with native species
  • Other interactions with native species (predation, hatch inhibition, parasitism)
  • Origin from temperate Asia
  • KEY ADAPTATION: Winter Diapause
  • 50
  • 40
  • 30
  • 20
  • 10
  • 0
  • 0
  • 20
  • 40
  • 60
  • 80
  • 100
  • U.S.
  • Asian
  • Latitude
  • Difference (%H, Long - %H, Short days)
  • Beijing
  • Korea
  • Tokyo
  • Kyoto
  • Nagasaki
  • Shanghai

Potential interactions with resident species

  • North:
  • Competition with treehole mosquitoes in treeholes and tires
  • South:
  • Competition with Aedes aegypti in open tire habitats
  • Competition with treehole mosquitoes in forested tires and treeholes
  • Predation
  • Parasitism

Topics, 2nd & 3rd Lecture

  • 2nd Lecture
  • Origins of Ecology
  • Influence of Evolution
  • Determining Inheritance
  • 3rd Lecture
  • Reasons to study Evolution
  • Criteria for Natural Selection
  • Forms of Selection
  • A sample of calculations involved in predicting changes in allele frequencies. The initial frequency of the a allele (p) is 0.4.
  • Genotype
  • aa ab bb Total
  • Number of zygotes 30 20 50 100
  • at time 0
  • Survival fraction 0.5 0.8 0.9
  • Number of adults 0.5x30 = 15 16 45 76
  • Number of successful 10 5 2
  • gametes per adult
  • Number of 10x15=150 80 90 320
  • successful gametes
  • produced
  • Fitness 0.5x10/2=2.5 2.0 0.9
  • New allele p=(150+80/2)/320=0.59 q=0.41
  • frequencies
  • Next fraction 0.592^2=0.35 2x0.59x0.41=0.48 0.402^2=0.17 1
  • of zygotes
  • Number of 0.35*320/2=56.4 77.2 26.4 147.8
  • zygotes at time 1
  • Figure 1. Changes in the frequency of allele a through time. Selection in this case is against allele b. For both cases, Waa = 1 and Wbb=0.5. For curve 1, Wab=0.5; for curve 2, Wab=1.
  • Selection against allele b
  • Creating ecological islands
  • Warwickshire,
  • England
  • Costa Rica
  • U.S.
  • Mainland
  • Orange environment
  • Population is all orange
  • p = 0
  • Inheritance:
  • aa: blue
  • ab: orange
  • bb: orange
  • OR:
  • aa: blue
  • ab: blue
  • bb: orange
  • Dispersal from Mainland to Island:
  • fixed fraction of individuals on island (I) have been
  • born on the mainland
  • Changes in the frequency of allele a through time for different fractions of immigrants to an island population. Selection in this case is against a dominant allele (b). I denotes the fraction of immigrant individuals arriving into the population with each generation. The initial frequency of the a allele in the island population is 0.2; mainland frequency=0. Fitness values are: Waa=1, Wab=0.5, Wbb=0.5.
  • Changes in the frequency of allele a through time for different fractions of immigrants to an island population. Selection in this case is against a recessive allele (b). I denotes the fraction of immigrant individuals arriving into the population with each generation. The initial frequency of the a allele in the island population is 0.2; mainland frequency=0. Fitness values are: Waa=1, Wab=1, Wbb=0.5.
  • Mainland
  • Population is all winged
  • p = 0
  • Island
  • Low initial fraction wingless (aa)
  • Some fraction of winged individuals disperse away from the island
  • Inheritance:
  • aa: wingless
  • ab: winged
  • bb: winged
  • OR:
  • aa: wingless
  • ab: wingless
  • bb: winged
  • Genotypes have same fitness
  • Dispersal from Mainland to Island:
  • fixed fraction of individuals on island (I) have been
  • born on the mainland (all winged, all bb)
  • Low I
  • High I
  • Low I
  • High I
  • Genetic Drift
  • N=10
  • N=20
  • Drift
  • N=20
  • N=100
  • N=1000
  • Chance deviations in frequency
  • result in loss of genetic variation,
  • especially in small populations

Measuring Genetic Variation

  • Gel electrophoresis
  • Alleles:
  • 1
  • 2
  • 3
  • Genotypes:
  • 12
  • 22
  • 23
  • Heterozygotes
  • 24
  • 12
  • Etc…
  • Do this for many individuals
  • Do this for many loci
  • Pgm
  • Heterozygosity: fraction heterozygous/locus
  • Genetic Variation
  • Finnish
  • Spittlebugs
  • Oropendula colony, Ecuador
  • Giant Cowbird
  • Oropendula
  • Oropendula egg
  • Cowbird eggs
  • mimetic
  • non-mimetic
  • Number of nestling Oropendula in nests
  • With Cowbirds Without Cowbirds
  • With Bot-fly parasites 57 382
  • Without Bot-flies 619 42
  • Fledgling success of oropendulas in discriminator and nondiscriminator colonies relates to the presence or absence of cowbirds:
  • Attributes of discriminator and nondiscriminator Oropendula colonies

Nonevolutionary Responses to Environmental Change

  • Organisms can change to perform better in different conditions, without a change in population genetic makeup
  • Time scales, mechanisms, flexibility
  • Regulatory Physiological/behavioral <<1 generation Reversible
  • Acclimatory Physiological/behavioral <1 generation Reversible
  • Developmental Developmental/behavioral ~1 generation Irreversible
  • Evolutionary Genetic/ecological >1 generation Reversible
  • Regulatory Responses
  • No morphological change required, involves physiology or behavior
  • Modified activity to maintain favorable body conditions
  • Examples:
  • Sweating, panting, shivering, altered kidney filtration, altered heart rate, drinking, basking
  • Objective: homeostasis-- buffer the internal environment of an individual, or to modify the immediate external environment.
  • Acclimatory Responses
  • Change in physiology, behavior, or morphology, in response to environmental changes, especially seasonal changes
  • Examples:
  • Fur growth
  • Color change
  • Foliage loss
  • Flowering
  • Mating coloration
  • Antler growth
  • Mating rituals
  • Feeding patterns
  • Responses to environmental cues (e.g. change in day length)
  • Developmental Responses (Phenotypic Plasticity)
  • Differences in body form or behavior depending on environmental
  • conditions

Induced defenses and cyclomorphosis

Nonevolutionary responses are not adaptations, but they are adaptive

  • Response itself is done without genetic change, but
  • the ABILITY to make the response has very likely evolved
  • through adaptation (i.e. natural selection)
  • Success of response
  • Survival and
  • Reproduction
  • Establishment and
  • Maintenance of population

Distributions

  • Summarize the locations where a species has been successful
  • Do not tell us about locations where they could be successful
  • Do not tell us about places where a species has failed
  • Understanding distributions relies on knowing what factors prevent species from occupying a particular location or region

Ranges

  • Geographic-- set of places actually occupied
  • Ecological-- set of places
  • with suitable conditions
  • Ecological > Geographic
  • Reasons why involve most topics
  • of interest to ecologists
  • A
  • B
  • C

Explaining an Absence

  • Species does not occur because:
  • It can’t reach it
  • It doesn’t choose to (habitat selection)
  • Physical or chemical conditions not favorable
  • Other organisms in the area prevent establishment (competition, predation, parasitism) or a key species (food, mutualist) is missing
  • Chance
  • Transplant experiments
  • Success: transplanted populations grow
  • Reject: physical/chemical factors
  • Reject: species interactions
  • Support: dispersal barrier
  • Failure: transplanted populations dwindle
  • Reject: dispersal barrier
  • Consistent with species interactions or physical/
  • chemical factors
  • Problem: ethical considerations of transplantation
  • Solutions:
  • Compare occupied and unoccupied environments
  • What major factors differ? --> hypotheses
  • Duplicate differences in laboratory setting
  • “Transplant” occurs in lab; hypotheses tested
  • limitation: lab setting
  • Conduct transplants in field under highly controlled conditions
  • Catch species in the act of invasion

Lessons from Invasions and Introductions

  • Starling
  • Gypsy moth
  • A albopictus
  • Failed introductions:
  • Fish stocking
  • Seeds in wool
  • Norway maple
  • Hessian Fly
  • Dutch Elm Disease
  • Chestnut Blight


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