Challenges facing Parasites, hosts as islands, how to infect new ones?High specificity, high fecundities, exploitation of vectors (mosquitoes)Intermediate and final hosts, host altered behavior (rabies, etc.)Assassin bugs (Triatoma)Malaria, protists (Plasmodium)Tapeworms (Cestodes), Nematodes (roundworms)Cholera (Shigella) transmission via dysenteryToilet seats, elevator buttons, door knobs, shopping carts...etc.Molecular mimicry: “eclipsed antigens” resemble host antigens hence do not elicit formation of host antibodiesMajor Histocompatibility Complex (MHC) Trypanosoma (protozoans) shed coats, change antigensFilariasis Elephantiasis (lymph nodes blocked by nematodes carried by mosquitoes)BotfliesDracunculus medinensis, caduceus symbol of medicine

Darwinian Medicine: don’t treat symptoms, distinguish between host defenses and parasite manipulation.Evolution of Virulence (benign parasites allow hosts to live)Host altered behaviorRabies virus — rabid animals bite, passes on virus to new hostLancet fluke Trematode Dicrocoelium dentriticumCercaria —> Metacercariae encyst on ant’s brainSheep ingest an ant and get infectedStarlings, Pill bugs, and AcanthocephalansDucks, Amphipods, and AcanthocephalansSTDs —> increased sexual activity?Ectoparasites (fleas, ticks, lice), endoparasitesSocial parasites (thievery, brood parasitism)Parasitoids: Ichneumonid waspsMicroparasites—> macroparasties—>parasitoids—>predator spectrum and many correlates thereof, such as relative sizes, rates of increase, number of parasites per host, virulence, stability, and ability to regulate lower trophic level

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

EnterobiusPinworms(Parasiteson Primates)

Parallel phylogenies

Primate hosts Enterobius species

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-canavanine, 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.

Wild ginger, Asarum caudatum, in western Washington are

polymorphic for growth rate, seed production, and palatabililty to

a native slug, Ariolimax columbianus (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.

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)_____________________________________________________________________________

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.

Parallel phylogenies: coevolution of pinworms and primate hosts

Drosophila pachea and senita cactus.

Danaid butterflies use polyuridine alkaloids to synthesize pheromones

l-canavanine, present in many legumes ruins protein structure

However, a bruchid beetle has evolved metabolic machinery

that enable it to use plants containing canavanine.

Correlates of plant apparency: quantitative versus qualitative defenses

Coevolution of wild ginger and slug

Antibiotics first discovered in fungi, but also occur in many plants.

Plant secondary chemicals have proven to be a vast reservoir for

useful pharmaceuticals — these include analgesics, diuretics, laxatives,

tranquilizers, contraceptive agents, and cough drops.

Clinically proven drugs derived from higher plants include morphine,

codeine, atropine, quinine, digitalis, and many others. Bark of Pacific

yew trees contains taxol, an effective agent for treating certain ovarian

Cancers (yew genes have been transplanted into bacteria which produce

commercial quantities of taxol in chemostats)

Scientists have only examined about 1 percent of existing plant species

for such useful pharmaceuticals.

Dan JanzenScheelea Palm

Bruchid Beetles

Pine squirrels (Tamiasciurus) andconiferous food trees (Smith 1970)

Squirrels are very effective seed predators, stockpile conesTrees reduce squirrel effectiveness in many different ways:1. Cones difficult for squirrels to reach, open, or carry2. Putting fewer seeds in each cone (fake cones without any seeds)3. Increasing thickness of seed coats (seeds harder to harvest)4. Putting less energy into each seed (smaller seeds)5. Shedding seeds from cones early, before young squirrels forage6. Periodic cone crop failures decimate squirrel populations

Individual trees out of synchrony would set fewer seeds and thusbe selected against.

Christopher Smith

Pharmaceuticalsanalgesicsantibioticsdiureticslaxativestranquilizerscontraceptives taxol (bark of Pacific Yew trees)

Janzen’s seedling ring hypothesis

Coevolution of pine squirrels (Tamiasciurus) and coniferous food trees

Phylogenetics in EcologyPhylogenetic Systematics = Cladistics

Importance of shared derived characteristics (synapomorphies)

Monophyletic groups = Clades

(Polyphyletic, Paraphyletic)

Sister groups, outgroups

Identify ancestral states — polarize character state changes

Phrynosoma

Moloch

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Evolutionary

Ecomorphology

Convergent Evolution Ecological Equivalents

Monophyletic Paraphyletic Polyphyletic

Phylogenetics in Ecology

Phylogenetic Systematics = Cladistics

Shared derived characteristics (synapomorphies)

Monophyletic vs. Polyphyletic groups

Sister groups, outgroups, rooting trees

Identify ancestral states — polarize character state changes

Minimum Evolution (maximum parsimony) shortest trees

Vicariance Biogeography and Area Cladograms

Phylogeny and the Modern Comparative Method

Phylogenetically Independent Contrasts

Evolutionary Ecomorphology

Convergence (homoplasy)

Willi Hennig

Inferring probable ancestral states

Inferring probable ancestral states

Estimation of ancestral states from those of extant descendents

Ray Huey Al Bennet

Mike Ryan Physolemus Frogs

Phylogenetics in Ecology

Phylogenetic Systematics = Cladistics

Shared derived characteristics (synapomorphies)

Monophyletic groups = Clades

Monophyletic, Polyphyletic, Paraphyletic

Sister groups, outgroups, rooting trees

Identify ancestral states — polarize character state changes

Vicariance Biogeography, Area Cladograms

Phylogeny and the Modern Comparative Method

Phylogenetically Independent Contrasts

Evolutionary Ecomorphology

Convergence (homoplasy)

Vicariance Biogeography

Area Cladograms

Area cladogram for Eublepharid Geckos

Aeluroscalabotes felinus BorneoAluroascalabotes (Borneo)

Goniurosaurus hainanensis, Hainan Island, China

Coleonyx brevis

Coleonyx mitratus

Coleonyx switaki Coleonyx variegatus

Heloderma suspectumHeloderma, North America

Lanthanotus borneensisLanthanotus, Borneo

VaVaranus giganteusVaranus giganteus, Australia

Independent Contrasts

Joe Felsenstein

Independent Contrasts

Joe Felsenstein

Independent Contrasts

Independent Contrasts

Independent Contrasts Pairs

Independent Contrasts Pairs

Independent Contrasts Pairs

Independent Contrasts Pairs