BSCI160 final

ecosystem processes

energy flow and nutrient cycling

ecosystem

organisms that live in an area plus their physical (abiotic) environment

components of an ecosystem

abiotic environment, primary producers, consumers, decomposers that are linked by movement of energy and nutrients

nutrients

building blocks of biological molecules

energy

required to assemble biological molecules

nutrient cycling

movement of chemical elements through ecosystem, recycled

energy flow

passes one way through ecosystems, cannot be recycled

Gross Primary Production

total energy from photosynthesis/area/time, energy from light converted to chemical energy

Net Primary Production

new biomass made per unit time, energy available to higher trophic levels (GPP-energy used for growth and maintenance)

biomass pyramids are typically wider where?

at base

energy pyramids are always wider where?

at base

pyramids of production are wider where?

at base

why do huge animals feed on tiny prey?

smaller organisms have greater energy value of new biomass

NPP in terrestrial ecosystems are limited by what

temperature, water, sunlight

NPP increases when temperature

increases

NPP increase when precipitation

increases reaches a plateu and then NPP decreases

where is terrestrial NPP highest

tropics (declines in high latitudes)

NPP in marine ecosystems is highest where?

in zones of upwelling and where rivers discharge nutrients into coastal waters

What is the NPP of marine ecosystems limited by

nutrients and light

percentage of total productivity of open oceans

24%

percentage of total productivity of tropical rain forests

23%

1st fact about earth

all life is cellular but some acellular life evolved from cells (viruses)

2nd fact about earth

there are a lot of different species of organisms on planet earth (1.5 million species) (estimated 5-10 million)

3rd fact about earth

there’s a lot of biomass on the planet (20 quadrillion)

4th fact about earth

life originated at the edge of the sea (land and freshwater were invaded multiple times, few habitats have not been colonized)

when was the origin of earth

\~4.5 bya

when was earth’s earliest life

\~3.5 bya

when were the earliest eukaryotes

\~1.5 bya

when were the earliest animals and land plants

\~500 mya

when were the earliest mammals

\~200 mya

when were the earliest homosapiens

\~200,000 ya

6th fact about earth

there are three major manifestations of multicellularity (coloniality, multicellularity)

coloniality

numerous origins

multicellularity

several origins (animals, plants, fungi, kelp, slime molds)

7th fact about earth

mass extinctions have punctuated the history of life on earth

background extinction

typical level of extinction, typical environmental change and competition (sometimes species go extinct because they are replaced by better adapted species)

mass extinctions

unusually high level of extinction, exceptionally harsh conditions (species dont get replaced by better adapted species)

8th fact about earth

major evolutionary innovations have occurred repeatedly (often results in naming monophyletic and paraphyletic groups) (can result in convergent evolution of key adaptive traits)

protists

mostly unicellular

another term for vertebrates

deuterosomia

what are most animals

invertebrates

what species belongs to winged-insect clade but does not have wings

Siphonaptera (fleas)

4 major groups of plants

nonvascular plants(mosses), vascular seedless plants(ferns),gymnosperms(pines, firs, redwoods), angiosperms(flowering plants)

9th fact about earth

well-adapted is contextual

surprising things can happen

examples of Indian pipe and carnivorous plants

what are the 3 types of zooids

1. ingestion, digestion 2. protection, feeding 3. reproduction

zooids

clones that arise asexually by budding from a zooid that develops from a fertilized egg

2 types of asexual reproduction

gametic (single cell develops into embryo then adult) and agametic (no embryo forms-budding, fission)

another word for gametic

parthenogenesis

innate behavior

inherited behavior that shows little variation based on past experience

when is innate behavior common?

when situation has high impact on fitness, when situation requires rapid, reflex-like response, when learning isn’t possible

aposematism

warning signal coloration

when is relying on instinct better than learning

if the cost of making a mistake is high, if the environment is predictable

learned behavior

change in behavior resulting from prior experience

imprinting

rapid, irreversible learning during a brief sensitive period

associative learning

acquired ability to associate one environment feature with another

classical conditioning

conditioned stimulus paired w unconditioned stimulus (Pavolv’s experiment)

operant conditioning

reinforcement of voluntary behavior occurs as a consequence of animal’s actions (strengthens association)

when is learning advantageous

when relevant environmental stimuli vary, learning opportunities are available, trial and error strategy is ok, efficient memory storage and processing

when is learning not advantageous

few opportunities to learn, mistakes are costly, benefit of learning is small compared to the cost

intraspecific behaviors

selfish, cooperative, spiteful, altruistic

selfish

\+/-

cooperative

\+/+

spiteful

\-/-

altruistic

\-/+

altruism is common among…

social species

inclusive fitness

own allele frequency in future generations can increase by producing offspring (direct fitness) and helping related individuals produce offspring (indirect fitness)

kin selection

natural selection that acts through benefits to relatives

reciprocal altruism

exchange of fitness benefits separated in time (blood sharing in vampire bats), groups that often interact, can lead to long-term associations

new world monkeys

arboreal, many w prehensile tails

old world monkeys

some arboreal, some terrestrial, none w prehensile tails

characteristic of apes

no tails

hominin

radiated into \~20 different species, bipedal apes, non-linear tree, coexistence

bipedalism

skull-spine connection

bipedal locomotion

frees forelimbs to manipulate and carry objects while walking, elevates eyes to see over tall grass, energetically more efficient

when did bipedalism evolve

\~4.5 mya

what evolved first bipedalism or large brains

bipedalism

where did homosapiens first evolve

africa \~300,000 ya

Out-of-Africa hypothesis

homo sapiens arose in Africa and then migrated out, fossil and molecular evidence

evolutionary history shapes our

minds and bodies

what was involved in human evolution

gene flow between partly diverged populations

human impacts on environment

global warming, habitat destruction, overharvesting, invasive species, biotic/ecological homogenization, nutrient enrichment, toxic chemicals

biotic homogenization

species invasions and extinctions change communities and often increase genetic, taxonomic, and functional similarities between two locations

what is a major homogenizing activity

urbanization

what is the annual deforestation

13 million hectares, 32 million acres, size of Greece

examples of invasive species

emerald ash borer, spotted lanternfly, zebra mussels, avian malaria, american chestnut

nutrient enrichment

excess nitrogen in aquatic ecosystems can lead to rapid growth of phytoplankton and algae, resulting in dead zones

biomagnification

concentration of toxins in higher trophic levels

connection between environmental justice and environmental racism

Chavis arrested for driving too slow, those causing most pollution are least affected

which president signed the NEPA, ESA, Clean Air Act extension and established the EPA

Nixon

what year was the first earth day

1970

norm shifting

people are influenced by what other people are or are not doing

biodiversity hotspots

high number of species in small areas

shifting baseline

each generation we adjust our psychological baseline (species abundance, amount of natural habitat, pollution levels, human population, etc)

Tragedy of the Commons

individuals behaving independently according to their self interest may harm the best interests of the group

externalities

costs or benefits that affect a party who did not choose to incur them (hidden costs)

Happy Planet Index (HPI)

life expectancy, experienced well-being, ecological footprint

genuine process indicator (GPI)

26 economic, environmental and social factors

sustainability

development that meets the needs of the present without compromising the ability of future generations to meet their own needs