bio 12 4th exam transcript

7/27/2019 Bio 12 4th Exam Transcript

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Ecology

Flow: Chapter 52, 56, 55, 53 (Population Ecology); September 28 (Evolution): Chapter 22

SEPTEMBER 18, 2013

Introduction to Ecology

-Do not confuse ecology with environmentalism

-Interview of Dr. David Schindler

Ecology-scientific study of the interactions between the organism and the environment (Slide 2)

Trees are cut and a stream is dammed. Beavers build lodges across a stream to build ahouse.

American Beaver (Castor canadensis) w/ large incisor teeth

Interactions determine the distribution and abundance of organisms (slide 2)

Early ecology was primarily descriptive and on natural history. Can be traced back to the Greek

thinkers

Plant ecology developed early.

Early ecologists studied plant associations (plant communities), which gave rise to community

ecologyVictor E. Shelford*

Community successionHenry C. Cowles

Succession in sand dunes

Ernst HaeckelAnimal ecologistcame up with the name ecology [in 1869]

Charles S. Eltonpopulation ecology of invasive species

animal ecology took off lateranimals as parasites (blood flukes in Schistosoma; intestinal nematodes passing out in thefeces)animals that feed on fecal material (dung beetle)Cannibalism; a male becomes a meal (praying mantis eats its mate)

The family that preys together, slays together.

Marine animal ecology flourishedAnimals with economic and medical importance were studiedcopepod that parasitized horn shark offcopepod paratisized by monogeneans

Parasitismlarva of avocado seed moth (Stenoma catenifer)Cotesia sp. (wasp): lay eggs (parasitoids: lay eggs on other insects) in the avocado seedmothparasitoid wasp is parasitized by a hyperparasitoid wasp which is also parasitized by asuperparasitoid wasp

Rise of modern ecologyG. Evelyn Hutchinson*

n-dimensional nicheFather of modern limnologyborn in the UK and studied in Cambridge; polymath at Yale (1903-1991)

Eugene P. Odum*

Father of modern ecologyWrote the First college-level textbook on ecology: Fundamentals of Ecology (1953)ecosystem ecology energy flow"The ecosystem is greater than the sum of its parts"studied under Victor E. Shelford at Illinois1940: arrived at University of Georgia; Set-up the Institute of Ecology in UGa laterrenamed Eugene P. Odum School of Ecology

Fundamental assumptions1. the ecosystem is the basic unit of nature2. biological diversity increases stability3. homeostasis is important at all levels of the biological spectrum4. "The ecosystem is greater than the sum of its parts"5. reductionist scientific methods cannot adequately explain living systems

Howard T. Odum*Energy systems modelSilver-Spring model

First complete analysis of a natural ecosystempassive electrical equivalent of Energy Systems Language storage icon

Environment, Power and Society (1976)

One of Hutchinson's ecological heirsArmando A. de la Cruz

Student of Eugene P. OdumDetritus as a major component of ecosystemsParticulate organic detritus in a Georgia salt marsh-estuarine ecosystems

Borrowed the name detritus from Geology

Modern ecology includes observation and experimentationsMicrocosms (Populations ofDapnia magna in plexiglass chambers on the lab bench)

Mesocosm (greenhouse experiments; fencing an experimental ecosystem; BioCON)

Large-scale experiment on the effects of elevated CO2 concentrations

Whole ecosystem approach (Experimental Lakes Area, ELA, in Canada)

Bloom of Cyanobacteria when Phosphorous is present in the Lake (226)


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SEPTEMBER 20, 2013

*Recall the experiment of Schindler in the Experimental Lakes Area (ELA)

Lake 226S was fertilized with C and N- no bloom of cyanobacteria

Lake 226N was fertilized with C, N and P- bloom of cyanobacteria

Oligotrophic lake

low in nutrients

Hungabee lake (canadian rockies)

Eutrophic lakehigh in nutrientslow water quality; poor claritylow levels of dissolved oxygen

Fish die off and fish have an off flavorcultural EutrophicationLake Taihu

Mercury levels in water were increased experimentally in mesocosms (enclosures)inorganic Hg became methylmercurymethylmercury gets inside fishes and the people who eat it get sick

Case Study: Nutrient Cycling in the Hubbard Brook Experimental Forest

In one valley, trees were cut down while the valley was treated with herbicidesThe research team constructed a dam to monitor water loss and mineralsWater loss is 30-40% higher than in control

Nitrate was lost by 60x moreResults show how human activity can affect ecosystems

Nutrient cycling ina forest ecosystem studied since 1963

Modern EcologyMore experimental and quantitativeMore long-term and large scaleMultidisciplinary

Enhanced by powerful computing, statistical analysis.data is shared and disseminatedinstruments are extensively used

Secchi disks measures depth of effective light penetration in water (clarity)Portable meters can measure abiotic factors in situDissolved oxygen meter, pH meter, thermometer

Can all be measured by Multi-parameter Benchtop MeterHas become very expensive

River Thames in BritainHeavily polluted before but is now very cleanStations are set up for monitoring water qualityYSI data sonde measures multiple parameters s/a DO, cyanobacteria growth, turbidity, pH,ammonia, etc.Stations need not be maned

Water quality data is recorded and transmitted via telemetry

Standard Plankton net

Back to Introduction to Ecology (given slides)

Biotic and Abiotic factors influence species distribution

Abiotic factorstemperature, water, light, nutrients, rock, and soil

Biotic factors

Predation, herbivory, competition

Rediscovery of nearly extinct harlequin toad (Atelopus varius) in Costa Rica

What environmental factors limit their geographic distribution?

What factors (food, pathogens) affect population size

Why are amphibians in general, disappearing world-wide?

Most likely due to a fungus, Batrachochytridium dendrobatidis

Scope ecological reserach

Organismal ecology

studies how an organism's structure and physiology meet environmental challenges

Population EcologyPopulation- a group of individuals of the same species living in an area w/c can

interbreeed

Population ecology-focuses on factors affecting population size over time

growth of locusts

exponential growth in African elephants

J-shaped growth-exponential growth

S-shaped growth-logarithmic growth

Bacterial growth curve

Community ecology

Community-group of populations of different species in an area

at least 2 species

deals with the whole array of biotic factors interacting in a community

ex. acacia tree and ants (Pseudomyrmex)

Ecosystem ecology

Ecosystem ecology emphasizes energy flow and chemical cycle

take a look at the overview of energy and nutrient dynamics of an ecosystem

Landscape ecology

landscape-mosaic of connected ecosystems


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Global ecology

Biosphere-global ecosystem; sum of all ecosystems

Global ecology examinse the influence of energy and materials across the biosphere

emergent properties at each levelpopulation dispersion

Uniform, clumped, randomCommunity succcessionCommunity interactionsCommunity species diversityEcosystem (energy flow, nutrient cycling)

SEPTEMBER 25, 2013

Biosphere

thin layer of all ecosystems, difficult to see edgewise from outer space

Situation: Corals die (bleaching of the maze coral

Meandrina meandrites)

Cattles eat corn which are planted where rainforests once stood, increased CO2 content

increased CO2 traps heat and acidifies seas

As the seas heat up, the polar ice caps melt

Figure 54.30. Tagging a gyrfalcon Falco rusticolus

May be a carrier of H5N1

Avian flu is a highly contagious virus

Ecologists study the potential spread of H5N1 from Asia to North america through migrating

birds such as the gyrfalcon

END OF CHAPTER 52

Chapter 56: Conservation Biology and Global Change

Scientists have named and described 1.8 million species

Biologists estimate 10-200 million species

Dr. Bruce M. Beehler studied the wattled smoky honeyeaterMelipotes carolae

Tropical deforestation is threatening this species

Western New Guinea

International Institute of Species Exploration

Lesula Monkey, Cercopithecus lomamiensis

Lyre sponge, Chondrocladia lyra. Found in very deep waters, carnivorous

Eternal light mushroom, Mycena luxaeterna, is bioluminescent

Monitor lizard, Varanus bitatawa

Hydraena ateneo, a newly discovered beetle

Today, we perhaps lose one species every single day

Conservation Biology

Integrates Ecology, Physiology, Molecular Biology, Genetics, Evolutionary Biology

Note concept 56.1

3 levels of biodiversityGenetic diversitySpecies diversityEcosystem diversity

Genetic diversity

Comprises genetic variation within a populations and between populations

Source of variations that enable populations to adapt to environmental changes

Tale of the banana

Ironically, the banana has had no sex for a thousand years

It was first propagated in jungles of Southeast Asia around 10,000 y.a.

Originated from Musa acuminata, whose hard seeds make its fruits inedible

Hunter-gatherers came upon mutant individuals that have since been cultivated

vegatatively. Mutant bananas are seedless, thus edible, but sterile

It has been at an evolutionary standstill and is genetically old and decrepit

Lacks genetic diversity, hence is vulnerable to Panama disease and black Sigatoka,wherein fungicides are ineffective.

Breeding programs are using disease resistant wild varieties are expensive

Sequence the genome of inedible wild bananas to find resistant genes t hat could be

introduced into the tissues of cells from edible varieties

Global collaboration led by INIBAP based in France

Overcome concerns about genetically modified bananas

Bananas are the 4th food crop next to wheat, rice and corn

The fate of bananas is the fate of millions

The demand for more bananas has led to loss of genetic diversity

Why evolutionary geneticists could go bananas

Genomic evolution is rarely observed

Genome of sterile bananas has been relatively unchanged

In contrast, wild bananas continue evolvingComparing genomes can reveal how genomes change over time

Was the forbidden fruit bitten by Eve really an apple?

"Banana: The fate of the fruit that has changed the world" by Dan Koeppel


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Species diversity

Important in maintaining structure of communities and food webs

Endangered species, in danger of becoming extinct throughout

Threatened species, likely to become endangered in the future

Vulnerable, rare or common

Hundred Hearbeat Club

Proposed by Edward O. Wilson

Lord of the Ants in Harvard

Memoirs: Naturalist

Prolific in writing. 2012. The Social Conquest of the Earth

Species listed are critically endangered

Philippine Eagle Pithecophaga jefferyi

Yangtze river dolphin, freshwater dolphin. Lipotes vexillifer

Extinct in 2006

Javan rhinoceros, Rhinoceros sonadicius

Local extinction of one species can have a negative impact of the ecosystem

Pteropus mariannus is an important polinator

Loss of species also means the loss of genes

Rosy periwinkle can cure some cancer

Ecosystem Diversity

Ex. Wetland ecosystem. Fig. 52-18c, 52-18f

What are wetlands for

Serve as havens for biodiversity

Filter off pollutants

Help prevent heavy flooding

Store nutrients

For the adventurous, where to to get wet and wild, to get stuck in the mud, to come face to face

with no-see-ums and other varmints

To get away from oneself

Fig 56.3

On Friday. Threats to Biodiversity

SEMPTEMBER 27, 2013

Threats to Biodiversity

Habitat destruction

The greatest threat to biodiversity

habitat destruction and fragmentation lead to loss of biodiversity

Prairies turning to human settlements

Destruction of the Amazon forest

Introduced species

moving species to new geographic regions

they may spread rapidly without their nativepredators, parasites and pathogens

disrupt the adopted community

Accidental species introductionbrown tree snake arrived in Guam as a "stowaway"

Originated from Australia

*Mark Jaffe writes about it in "And No Birds Sing"

Counteroffensive involved dead toxic mice

Introduction of species with good intentions

kudzu (Pueraria lobata), fast growing invasive species

Golden apple snail Pomacea canaliculata from Taiwanwas intended to provide protein for

Filipinos. Might have displaced the native species Pila conica

Overharvesting

gathering of wild plants or animals at rates exceeding the ability of populations to recover

large organism with low reproductive rates are especially vulnerable

elephant ivory tusks

DNA analysis can help identify source of illegally obtained animal productsoverfishing has decimated wild fish populations like North Atlantic bluefin tuna

Pacific bluefin tuna (Thunnus orientalis) are also hunted

Global Change

alterations in climate, atmospheric chemistry and broad ecological systems

acid precipitation contains HNO3 and H2SO4 coming from Fossil fuels

it kills trees and other lake-dwelling organisms

it also defaces stone art


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Population ecology

focuses on population size, genetic diversity and critical habitat

2 approaches

1.) Small population approach

Considers conditions that make small populations become extinct

The extinction vortex: evolutionary implications of small populations

Key factor driving extinction vortex is loss of genetic variation

Decline ofTympanuchus cupido

it has been proven that low genetic variation is in fact how the extinction vortex works

Minimum Viable Populationsmallest number of individuals that can keep a population growing

Effective Population size based on populations breeding potentialNe=(4NfNm)/(Nf+Nm)Nf is # of females and Nm is the # of males

case study, grizzly bear populations.It is estimated that 100 bears would have 95% chance of surviving for 200 years400 grizzly bears in YSNP

Urus arctos horribilis

2.) Declining Population approach

Emphasizes the environmental factorsFocuses on threatened and endangered populationsBengal florican Houbaropsis bengalensisRed-colored woodpeckerPocoides borealis

requires living trees in mature pine forestslow undergrowth

Species had been forced into decline by habitatSEE JIAN NOTES

SEPTEMBER 28, 2013

EVOLUTION

Book: Portraits of Great American Scientists by Elizabeth A. Gilbert

Geerat J. Vermeliborn in the Netherlands and went to Princeton University, PhD in Yale after he was a highschool valedictorian.top malacologist (studies snails and mollusks); well publishedevolutionary "arms race"editor/ associate editor ofScience, Evolution, Paleobiologyunusual childhood glaucoma; sees gastropod mollusks with his handsDistinguished professor in Marine ecology and paleoecology at UC-Davis

Pigeons have an array of variations in color, shape and formNature selected which individuals would be able to reproduce

Reproduction-->Ecology-->Evolution--->DiversityFigure1.UN09

mother-of-pearl plant (ghost plant) [Graptopetalum paraguayense]native to northeastern Mexicofresh succulent leaves store watergrows in crevices of vertical rock walls, where there is little soil to hold rainwater.

also found growing in Baguio City

Namib desert: a sea of sandWelwitschia mirabilis, an endemic gymnosperm; tweeblaarkanniedoodOnymacris unguicularis (Coleoptera), darkling beetle; the headstanding beetle and fog-basking beetle

allows water droplets to condense in its legs to obtain waterthere are 350,000 species of beetles (Coleoptera); 3 pairs of legs, hard outer

surface and 2 pairs of wingsWhy are there so many beetles? Because they have various adaptations to theenvironment

3 observationsunity of liferemarkable ways by w/c an organisms are suited to the environmentdiversity

Essay in 1973 in American Biology Teacher by Theodosius Dobzhansky, an evolutionary biologist

and geneticist

"Nothing in Biology makes sense except in the light of evolution"

Overview: Endless forms most beautiful, Origin of Species by Charles Darwin

Darwin noted that current species are descendants of ancestral species

Evolution can be defined by descent with modification

Species were created and are immutable (unchanging); view held by the Old testamentSee slides for more details (lol)

Wild mustard


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SEPTEMBER 30, 2013

[AFTER THE BONUS]

Create fewer large reserved or more numerous small reserves?

Smaller reserves may be more realistic and may slow the spread of disease throughout a

population

Large for ranging animals

Zoned reserves

Costa Rica has been successful in making zone reserves

Some marine zoned reserves in the Fiji islands. It even improves fishing success in nearby areasFlorida Keys National Marine sanctuary

Human caused changes in the environment include (part of global change)

Nutrient enrichmentHarvest of agricultural crops export nutrients from the agricultural ecosystem

Agriculture leads to the depletion ofnutrients in the shouldFertilizers add Nitrogen and other nutrients to the agricultural ecosystem

[Harmful because nutrients is either gained or lost by the ecosystem]

*Critical Load: the amount of added nutrient that can be absorbed by plants without damaging ecosystemintegrity

Agricultural runoff and sewage lead to phytoplankton blooms (HABs) in the Atlantic Ocean.

Fish kills cased by Pfiesteria piscicida triggered by high nitrogen levels from pig farms

*Decomposition of phytoplankton blooms causes "dead zones" due to low oxygen levels

Show photographs! Explain situation.

Toxins in the environment (see slides) just additional info

PCB-PolychlorinatedBiphenyls

Herring gulls of the Great Lakes lay eggs with PCBs 5000x greater than that found in phytoplankton

An example of Biological Magnification

Disrupts Calcium deposition in eggshells

DDT-dichlorodiphenyltrichloroethane

"Silent Spring" by Rachel Carson

brought the attention of the biomagnification of DDT in birds

DDT was eventually banned in the US in 1971

It also kills malaria vectors

CO2 levels. Figure 56.28Greenhouse effect

OCTOBER 2, 2013

Chapter 55: Ecosystems and Restoration Ecology

Overview: Cool ecosystems

An ecosystem consists of all the organisms living in a community as well as the abiotic factors

eye-in the-sky photograph of Taylor Valley and the area

Why is this ice in the Antarctic blood red?

Blood falls in Taylor glacier

Very cold but water is unfrozen since it is hypersaline

No oxygen and no light

High in sulfate, iron, and Carbon

Locked in for 1,500,000 and 2,000,000 years

Below the glacier; 17 species of Chemoautotrophic bacteria metabolize sulfate and iron

Water seeps upward and the ferrous iron is reoxidized to ferric iron upon exposure to air.

Ferric iron makes the water bloody red

Hence, the glacier is blood red due to the ecosystem of bacteria below

A desert world. A desert spring ecosystem

Megan Young is also an ecosystem (lol)

temperature, pH, water, biological gases, nutrients, elements, metabolites urea and a bit of

ammonia

bacteria, parabasalids, small arthropods, roundworms, etc.

Regardless of an ecosystems size, its dynamics involve 2 main processes:

Energy flow and nutrient cycling

Energy flows through the ecosystem while nutrients are recycled


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Ecologists study the transformations of energy and matter within ecosystems

Conservation of Energy. Laws of physics and chemistry apply to ecosystems

1st Law of thermodynamics: Energy is neither created nor destroyed

Energy enters an ecosystem as solar radiation and is kept as heat

2nd Law of thermodynamics: Entropy of the universe always increases

In an ecosystem, energy conversions are not completely efficient

The amount of energy in the universe has been fixed since the beginning of time and will

remain as such until the end of time

The total energy content of the universe is constant

Autotrophs build molecules themselves using photosynthesis orchemosynthesis

Heterotrophs depend on biosynthetic outputs of other organisms

Note energy flow and nutrient cycle

Detritivores and decomposers are consumers that derive their energy from detritus,

nonliving organic matter that is breaking down

Detrivores are invertebrates that reduce the size of detritus

example: termites, ants, millipedes, earthworms and dung beetles

Scat-animal feces

Fungi are decomposers

Concept 55.2

In a few ecosystems are chemoautotrophic bacteria; a deep-sea hydrothermal vent

community; polochaetes

Only a small fraction of solar energy actually strikes photosynthetic organisms, and even

less of a usable wavelengthOnly 51% is absorbed at the surface

7% of UVR reaches the surface of the Earth; 45% visible light

Wavelength of light are the most effective in driving photosynthesis

Gross Primary Production- Total primary production

Net Primary Production-GPP- energy used by primary production for respiration (R)

Only NPP is available to consumers

Ecosystems vary greatly in NPP and contribution of the total NPP of the Earth

Tropical rainforests, estuaries and coral reefs are among the most productive ecosystems per

unit area

Marine ecosystems are relatively unproductive per unit area but contribute much due to their size

Net ecosystem production (NEP) is a measure of the total biomass accumulation during a given

period. NEP is gross primary production minus the total respiration of all organismsEstimated by comparing the net flux of CO2 and O2 in an ecosystem, two molecules

connected by photosynthesis.

The release of O2 by a system is an indication that it is also storing CO2

NOTE THE MEASUREMENT OF OCEAN PRODUCTION

Primary production in aquatic environments

Light limitation; Photic zone- Depth where light penetrates

Nutrient limitation; usually Nitrogen and Phosphorus

Figure 55.8

Experiments in Sargasso Sea

In lakes phosphorus limits cyanobacteria growth

In some areas, sewage runoff has caused eutrophications which almost always result to bad things

such as fish kills

Fig 55.9Various adaptations help plance access limiting nutrients from soil

Secondary production; Production efficiency (note equation)

Fig 55.10

Trophic efficiency; it is usually about 10%

An idealized pyramid of net production

Plants can only fix 1%

Eating plants get 10% of energy

Eating 1* consumers only 10%

Approximately 0.1% of chemical energy fixed by photosynthesis reaches the tertiary consumer

"Food Matters" and "Fast Food Nation" Mark Bittman

Cows emit CO2 and methane

bio 12 4th exam transcript

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