1. Ectoparasites, endoparasites Social parasites: Brood Parasitism
Parasite–Predator spectrum
Microparasites: Viruses, Bacteria
Macroparasites: “Worms” Cestodes
Parasitoids: Ichneumonid wasps ——>
Predators
Mode of transmission & virulence
25th Lecture
30 November 2017

2. Opuntia Prickly Pear Cactus and Cactoblastis Moth

15. Asian Toad, Duttaphrynus melanostictus

16. Epidemiology Basic reproductive rate of infection (does one infection result in one new infection?) Threshold host population size

17. Sigmoidal time course of an epidemic
dI /dt = b IS dS/dt = – b IS

18. Darwinian Medicine don’t just treat symptoms identify host defenses fever and inflammation iron additives Vitamin C and cancer Antibiotic resistant strains Application of an evolutionary approach to medical treatment

19. Methicillin-resistant Staphylococcus aureus (MRSA)

20. Darwinian Medicine don’t treat symptoms host response or parasite manipulation? fever and inflammation iron additives Vitamin C and cancer Antibiotic resistant strains Application of an evolutionary approach to medical treatment
R. M. Nesse
G. C. Williams

22. Coevolution Joint evolution of two (or more) taxa that have close ecological relationships but do not exchange genes, and in which reciprocal selective pressures operate to make the evolution of either taxon partially dependent on the evolution of the other

23. Modes of transmission. Airborne: Flu Virus. Waterborne: Cholera
Modes of transmission Airborne: Flu Virus Waterborne: Cholera Food: Salmonella Contact: STDs, Ebola Intermediate Hosts: Malaria

24. Enterobius
Pinworms
(Parasites
on Primates)

25. Parallel phylogenies Brooks and Glen 1982 Enterobius species
Primate hosts

26. Drosophila pachea and senita cactus.
Danaid butterflies use polyuridine alkaloids as chemical precursors for synthesis of pheromones used in attracting mates.
An arginine mimic, l-canavavine, present in many legumes,
ruins protein structure in most insects.
However, a bruchid beetle has evolved metabolic machinery
that enable it to use plants containing canavanine.

27. Wild ginger, Asarum caudatum, in western Washington are
polymorphic for growth rate, seed production, and palatabililty to
a native slug, (Cates 1975).
Where slugs are uncommon, plants allocate more energy to
growth and seed production and less to production of antiherbivore
chemicals. In habitats with lots of slugs, less palatable plants have
a fitness advantage — even though they grow more slowly, they
Lose less photosynthetic tissue to slug herbivory.

28. Some of the Suggested Correlates of Plant Apparency
_____________________________________________________________________________
Apparent Plants Unapparent Plants
Common or conspicuous Rare or ephemeral
Woody perennials Herbaceous annuals
Long leaf life span Short-lived leaves
Slow growing, competitive species Faster growing, often fugitive species
Late stages of succession, climax Early stages of succession, second growth
Bound to be found by herbivores Protected from herbivores by escape in
(cannot escape in time and space) time and space (but still encountered by
wide-ranging generalized herbivores)
Produce more expensive quantitative Produce inexpensive qualitative chemical
(broad-based) antiherbivore defenses defenses (poisons or toxins) to discourage
(tough leaves, thorns, tannins) generalized herbivores
Quantitative defenses constitute Qualitative defenses may be broken down
effective ecological barriers to her- over evolutionary time by coevolution of
bivores, although perhaps only a weak appropriate detoxification mechanisms in
evolutionary barrier unless supple- herbivores (host plant-specific herbivore
mented with qualitative defenses species result)
Paul Feeny

29. Daniel Janzen

30. Pine squirrels (Tamiasciurus) and
coniferous food trees (Smith 1970)
Squirrels are very effective seed predators, stockpile cones
Trees reduce squirrel effectiveness in many different ways:
Cones difficult for squirrels to reach, open, or carry
Putting fewer seeds in each cone (fake cones without any seeds)
Increasing thickness of seed coats (seeds harder to harvest)
Putting less energy into each seed (smaller seeds)
Shedding seeds from cones early, before young squirrels forage
Periodic cone crop failures decimate squirrel populations
Individual trees out of synchrony would set fewer seeds and thus
be selected against.

31. Modes of Transmission of Parasites
Biological Control
Oryctolagus x Myxoma
Opuntia x Cactoblastis
Cane Toads, Asian Toads
_____________________________________________________________
Darwinian Medicine:
Application of an evolutionary approach to medical treatment
Don’t treat symptoms. Distinguish host defenses from parasite manipulation
Coevolution
Pinworms x Primates
Drosophila pachea and Senita cactus
Wild ginger, Asarum caudatum, and slug Ariolimax columbianus
Plant Apparency
Expensive quantitative vs inexpensive qualitative chemical defenses
Janzen’s Seedling Ring Hypothesis Pine squirrels (Tamiasciurus) seed predation and coniferous food trees

32. Community and Ecosystem Ecology Macrodescriptors = Aggregate Variables Trophic structure, food webs, connectance, rates of energy fixation and flow, ecological efficiency, species diversity, stability, relative importance curves, guild structure, successional stages Bottom Line: Communities are not designed by natural selection for smooth and efficient function, but are composed of many antagonists (we need to attempt to understand them in terms of interactions between individual organisms)

33. Gross Productivity = rate at which plants capture solar energy
Energy Flow and Ecological Energetics
Gross Productivity = rate at which plants capture solar energy
Gross annual production (GAP)
Net productivity = gross productivity minus respiration losses
Net annual production (NAP)
Respiration in tropical rainforest 75-80% of GAP
Respiration in temperate forests % of GAP
In most other communities, it is % of GAP
Only about 5-10% of plant food is harvested by animals
Remainder of NAP is consumed by decomposers
Biogeochemical cycles

34. Biogeochemical Cycle for Calcium
Hydrologic Cycle
Aldo Leopold, A Sand County Almanac X

35. Compartmentation
Trophic Levels
Autotrophs = producers
Heterotrophs = consumers & decomposers
Primary carnivores = secondary consumers
Secondary carnivores = tertiary consumers
Trophic continuum
Horizontal versus vertical interactions
Within and between trophic levels
Guild Structure
Foliage gleaning insectivorous birds
Food Webs
Subwebs, sink vs. source food webs
Connectance [n (n-1)] / 2

37. Energy Flow and Ecological Energetics

38. Energy Flow and Ecological Energetics

39. Energy Flow and Ecological Energetics
At equilibrium (dLi/dt = 0 for all i), energy flow in the system portrayed in the figure may thus be represented by a set of simple equations (with inputs on the left and rate of outflow to the right of the equal signs):
l10 = l01 + l02 + l03 + l04
l10 = l21 + l01 + l41
l21 = l32 + l02 + l42
l32 = l03 + l43
l41 + l42 + l43 = l04

40. Systems Ecology

41. Food Web Chiton Patella Mytilus Balanus Mitella Pisaster R. T. Paine
(1966)
Thais
Chiton Patella Mytilus Balanus Mitella

42. Food Web
Bottom Line

43. Food Web
Bottom Line

44. Food Webs
Kirk Winemiller

46. Ecological Pyramids (numbers, biomass, and energy)
Pyramid of energy
Measures of standing crop versus rates of flow

48. Secondary Succession

49. Institute Woods in Princeton
25, 65, 150, 350 year-old stands

50. Transition Matrix for Institute Woods in Princeton 11 species of trees
_________________________________________________________________________
Canopy Sapling Species (%)
Species BTA GB SF BG SG WO OK HI TU RM BE Total __________________________________________________________________________
BT Aspen
Gray birch
Sassafras
Blackgum
Sweetgum
White Oak
Red Oak
Hickory
Tuliptree
Red Maple
Beech
__________________________________________________________________________
BTA in next generation = 0.03 BTA SF BG Grand Total = 3286
Henry Horn

51. Distributions of Trees Observed in 4 Forests and Predicted Climax
__________________________________________________________________
Age (years) BTA GB SF BG SG WO OK HI TU RM BE __________________________________________________________________
Predicted
climax
__________________________________________________________________ __________________
Data from the
Institute Woods in Princeton (Horn 1975)
Henry Horn

52. Diversity and Community Stability
Diversity and Community Stability Saturation with Individuals and with Species Species Diversity = Biodiversity Species Density or Species Richness Relative Abundance/Importance Equitability

53. Species Diversity, Relative Abundance. Species. Site A. Site B. A. 10
Species Diversity, Relative Abundance Species Site A Site B A B C D E F G H I J