SIO 132 Midterm 3 and Final

Ecology

Ecology

scientific study of the distribution and abundance of organisms, including causes and consequences

Autecology

How an individual species lives (self-ecology)

- like a barnacle with a thick shell in the intertidal

Population ecology

factors that influence a population's distribution

Community ecology

studying more than one species

Types of community ecology

Interaction ecology - looking at prey and predator of host and parasite (considers all sides of 2 or 3 species' interactions)

Assemblages - types of living styles, i.e. - benthos, pelagos, nekton, etc

Food Web ecology - true community ecology, combines assemblages and interaction ecology

Ecosystem ecology - abiotics mix with biotics - inputs, outputs, energy and minerals

Ecological niche

environmental requirements of a species to have greater birth than death rates along with the effects of the species on those environmental conditions

Fundamental niche

set of environmental requirements permitting species to persist

Realized niche

where a species is restricted, negative reactions with other species

Draw the visual for the relation between fundamental and realized niches.

Fundamental niche encompasses a larger area than the realized niche. (Realized niche is within fundamental niche.)

interspecific competition

species contend for the same limited resources (overlapping niches). The species negatively influence each other's population growth rates.

Exploitation competition

reducing resource supply, the species may never see each other

Interference competition

direct physical interaction, one displaces other from getting resources

What is the limiting resource for organisms in the rocky intertidal zone?

Space

What is an example of an organism in the rocky intertidal that represent conspicuous members of a rocky intertidal community? What challenges do they face?

Barnacles, they'll die if dislodged, and space is tight

Draw a visual for the observations between Chthalamus and Semibalanus.

Same as fundamental versus realized niche. The two fundamental niches overlap, but the realized niches do not because they out-compete. Chthalamus is successful higher in the zone, while semibalanus outcompetes chthalamus deeper.

Draw a visual of the Paine 1966 removal experiment between sea stars, barnacles, and mussels.

When sea stars were removed, mussels reproduced out of control and outcompeted barnacles because sea stars preferred mussels. (Competitive Exclusion)

Competitive exclusion

prevented when dominant competitor is the preferred prey of the keystone predator

Keystone species

affects community structure disproportionately to its abundance

What is an important piece of info regarding the way that mussels exclude other species?

They not only exclude barnacles, but other "primary space holders"

Interaction strength

measure of effect of one species' population on the size of another species' population

What happened between the interactions of the two predators (Nucella and Pisaster) with Mytilus?

Since Pisaster is the stronger interactor, when it is removed the weaker one (Nucella) substantially impacts prey

What are the conspicuous behaviors that cause Euhaplorchis californiensis to attract predators for the second stage of the flatworm's life cycle?

Surface swimming, shimmy, jerk, contort, scratch

What was concluded about the relation of infected fish to the number eaten by birds?

Parasites control who dies and how (via predation), this likely alters the strength of this link to the food web.

What was concluded about the study of trematodes and clams in the NZ mudlflats?

They altered the mudflat community structure and boosted local diversity.

How is a food web usually depicted?

As a map of who eats whom.

Topology

link of patterns of a network, no interaction strength

What is connectance?

proportion of possible feeding links between species that actually occur (L/S^2). It is a basic metric for food web theory, and influences stability.

What is the 10% rule?

an average of 10% of energy is transferred from one trophic level to the next.

Why is only 10% transferred to the next trophic level?

organisms burn a lot of energy for maintenance, so things are rarer at higher trophic levels.

What is the characteristic like of an adult male fiddler crab? How does this help and hurt the animal?

Sexes are dimorphic, TTP's cause the crab to swing his claw more to attract predators, and this also attracts mates

What is the biological definition of a colony?

When cloned organisms stay together and are physically connected. (Marine colonial inverts)

What is the sociobiological definition of a colony?

Society - group of conspecifics living in organized, cooperative fashion

Colony - highly integrated society, individuals physically united or have division of labor

Division of Labor (DOL) - individuals in colony form castes that specialize on certain tasks

Reproductive DOL - reproductive and non-reproductive castes

What are examples of planktonic colonies with DOL?

Siphonophores and salps

What are examples of benthic colonies with DOL?

Hydroid polyp stages and bryozoans

What are castes?

reproductives and non-reproductives (soldiers)

How can we have a reproductive DOL if natural selection is about passing on genes?

by helping kin reproduce, you help pass genes. Monogomy and outcrossing causes you to be as related to siblings as you are to offspring

What is inclusive fitness, and where do we see it?

An individual's direct fitness (personal reproductive success) plus indirect fitness (reproductive success of kin obtained with individual's help), in colonies with reproductive DOL

What are characteristics of the sea anemone colony?

they form clonal societies of polyps on rock, soldiers live near borders and have little gonads but lots of fighting tentacles, reproductives live at centre of group

What is an example of a colonial marine organism with DOL?

Eusocial snapping shrimp, colonies live in sponge canals with few queens and many soldiers, sponge is food (they are typical parasites)

What happens when another trematode flatworm colony tries to invade a host that's already occupied?

The colonies fight. The soldiers are smaller than the reproductives and the reproductives are large. The pharynx size compared to body size in soldiers is large.

Symbiosis

long-term living together of two heterospecific individuals

What are the four types of symbiosis? Give examples.

Commensalism( symbiont +/host -) skeleton shrimp on sea star, Mutualism (+ symbiont/+ host) anemone and clownfish, Parasitism (+ symbiont/- host) shark and tapeworm, Enslavement (- symbiont/+ host) corals and zooxanthellae

What is a major issue for fish?

Lots of ectoparasites and micropredators that can reduce health and growth of host.

What are cleaning mutualisms?

non-symbiotic mutualism between cleaners and clients

Cleaning behavior

removal of ectoparasites and micropredators from client hosts

What are examples of cleaners?

wrasses and gobies

What are characteristics of cleaner organisms?

conspicuous coloration and behavior, set up cleaning stations, visited by clients

What are characteristics of clients?

stereotypical soliciting behavior, stop swimming, hold head up (or down), hold mouth open. Don't eat cleaner

What was concluded about the cleaner experiment?

Fish w/ cleaners had 1/4 of micropredators

How can cleaning mutualisms be exploited?

cleaners use aggressive mimicry by imitating the coloration and behavior of cleaners

Aggressive mimicry and example

a consumer species resembles a harmless one to gain access to food, anglerfishes or blennies (cleaner mimics)

Batesian mimicry and example

a harmless species resembles a harmful one to avoid predators, filefish mimicing pufferfish or mimic octopus

Social mimicry and example

similar (but unrelated) species school together for protection, damselfish and blenny

What is a facultative cleaner?

One that doesn't always clean, only does sometimes, like the senorita fish in La Jolla

What is a cost for cleaners?

Getting ectoparasites transmitted from client.

What do cleaner fish help reduce in the client relationship? What do they do when micropredators are rare?

micropredator intensities and variance in intensity among sites. Become micropredators

What two fish reduce micropredators and ectoparasites on kelp?

senoritas and surfperch

Is the relationship between kelp and cleaner fish a mutualism?

Yes, loosely. Because both benefit, but the kelp doesn't really do anything

Where do mimics outnumber their models, and what does this cause?

Cabo Pulmo, blennies no longer resemble the wrasse, so are no longer mimics

Biogeography

study of the definition of species and ecosystems in geographic space and through geological time

What is the Latitudinal Diversity Gradient (LDG)?

greater number of species in tropics compared to temperate and polar regions, one of the most pronounced and pervasive patterns that characterizes life on Earth

What do shelf bivalves tell us about marine LDGs?

That there's more diversity in their species, genera, and families at the equator

What is true about latitudinal diversity of benthic taxa?

It's greater at the lower latitudes

What is true about the peaks of benthic taxa in the East and West Atlantic?

Diversity peaks a bit north of the equator.

What impact does the Amazon River have on the diversity of marine organisms?

it removes a typical marine habitat because of its sediment deposition, and blocks Caribbean flora and fauna

Meta-analysis

statistical analysis that combines the results of multiple scientific studies

Why does the LDG account for more diversity in the tropics?

broader historical/evolutionary factors and local ecological explanations

Tropics as Cradle

taxa diversity originates in tropics

Tropics as Museum

extinction rates are lower at equator

Tropics as Immigration Pump

species in tropics spread out to other latitudes

Why is speciation greater in the tropics?

higher temperature causes faster mutations and interactions between species

Why are pinnipeds not affected by the speciation speed at the equator?

They are warm-blooded and generate their own heat with CC Heat exchange

What are characteristics of areas with distinct biota?

groups of species with shared/congruent evolutionary history, sometimes with operational rules (endemism)

Endemism

% of species that are unique to a defined geographic area

What areas do species originate with the highest diversity?

Temperate Northern Pacific, Antarctic, Caribbean, Coral Triangle

What are the two main tropical centres of diversity?

Indo-Pacific and Caribbean

Qualities of the North Pacific

separated from the Arctic and North Atlantic for 70my. Trans-arctic interchange happened - 3.5 mya warm period, biotic interchange was from mostly Pacific to Atlantic and 295 molluks went back and forth. 261 are Pacific origin. Invasion

Antarctic shelf benthic communities

shallow benthos dominated by epifauna, lots of sessile suspension feeders, lack of shell-crushing predators : similar to Paleozoic benthic communities, massive endemism (>50%)

What unique animals are in the Southern Ocean?

Pycnogonids and decapods

Origin of unique Antarctic benthic communities

persistence of some Mesozoic and early Cenozoic taxa (from when it was temperate), extinction of many early tertiary warm-temperate spp, isolation 20ma opening of Drake's Passage (w/ Australia) -> Antarctic Circumpolar Current (ACC), invasions by cold temperate spp from North hemisphere

What kind of parasites are in the horn snails in North and Central America?

trematode parasitic castrators that have rapid, wide dispersal. The bird dispersal is also fast and far (precludes speciation from driving latitudinal diversity gradient)

What was significant about the findings of the trematode population diversity?

It was a reversed representation of the typical LDG generalization

What is an explanation for trematodes having higher diversity outside of the tropics?

their horn snail hosts have greater mortality at the tropics, greater population extirpation, smaller population size, and greater spatial patchiness

What does the reversed trend in LDG trematode species say about LDGs?

local factors can play a significant role in LDG distribution

Fossil

any indication of a lifeform from a past geological age

Body fossils

preserved remains of body/cell, usually lithified, casts/molds

trace fossils

trace of an organism's activity: foot prints, tracks, burrows, teeth marks, nests, coprolites (fossilized shit)

Chemical fossils

biosignatures, biogenic chemicals

When and how did we first see carbon fixing?

3800 mya, biogenic carbon, light carbon in some minerals that is only known to occur in C-fixing

Uniformitarianism

assumption that the same natural laws that operate now, operated in the past

When was cyanobacteria found in Earth's history?

3.65 bya, so well preserved that it could be 11 diff species

When did microbial mats emerge? What concept does this help to give evidence for?

3.48 bya, uniformitarianism

When were prokaryotic body fossils found?

3500 mya

What characterizes the Great Oxygen Revolution/Catastrophe?

oxygen killed a lot of species 2500 mya, opened door for new species and aerobic respiration and larger, more complex ,life forms

What happened 1200 mya?

multicellularly sexual reproductive fossils found

What happened 800-600 mya?

first animal fossils found, as well as DNA clocks, coincides with O2 levels rising to 1-3% present levels

When was the Vendian biota (Ediacaran fauna), and what were its characteristics?

just before Phanerozoic (560 mya), first large animals, simple organization (no hard parts), most epifaunal and surficial (barely any erect), sessile and slow, lots of deposit feeders

When was the Cambrian explosion? What were its characteristics?

540 mya, most modern phyla appear within 20 mya, many extinct groups within those phyla, hard parts and more burrowing, first pelagics, some fast animals, more typical predators

What did the Sepkowski studies conclude?

As the Phanerozoic progressed, there was an emergence of more and more families. There was an increase in "tiering" and evolution to more thoroughly use "ecospace"

What ecospaces were found to increase from the Ediacaran to present day, according to the Bush&Bambach studies?

Predation/defense, motility, infaunality, biological disturbance, and energy use