Biodiversity
Terms
undefined, object
copy deck
- Three kinds of biodiversity
-
Genetic
Species
Ecological - Genetic
- Variety within the same species
- Species
- #of different species in a ecosystem
- ecological
- diversity within a community
- The new wave
- use of molecular techniques
- 3 ideas o categorize species
-
number of niches
number of trophic levels
amount of energy - how species do we know of so far?
- 1.4 million
- what group of species are the most numerous?
- inverts (no backbones)
- What do we get from the abundant life forms on the planet?
- food, drugs and medicines, ecological benefits (water treatment), Aesthetic Benefit (charismatic creatures)
- extinction
- elimination of a species from a planet
- is extinction a bad thing?
- no
- What causes species to go extinct?
- mutation and natural selection, new form can repace an old one, new species ot competes different species
- How many mass extinctions have their been?
- 5
-
cretaceous
permian -
loss of dinosaurs
2/3 of marine species and half of all animals and plants 250myo - what are the mojor current causes of extinction?
- habitat removal, pests, disease, pollution
- kudzu
- erosion control
- learfy spurge
- entire plant is poisonor
- whirling disease
- attacks cartilage and cases funky swimming
- fungal blight
- decimated the American Chestnut
- Bioacuumulation and biomagnification
- gets more (the larger the fish)
- ESA
- Endagnered Species Act developed in 1973
- Endangered
- soon to become extinct
- Threatened
- soon to enter the endangered species list in near future
- Vulnerable
- rare or at risk; rare because of natural and human causes
- HCP
- Habitat conservation plans- can harvest but need to make sure it doesn't affect endangered species
- Effects of small population size
- loss of genetic diversity, loss of diversity decreases the ability to adapt and reproduce
- MVP
- Minimum viable Population- balance between large and small, close and far
- Safe Harbor and No Suprises
- if someone from HCP comes over to check on the grizzly bears a farmer had on his land, if he notices that there are 5 more than the original 2, the farmer still only has to protect those 2, not the other 3
- 3 stages within the ESA act are:
- Vulerale, threatened, extinction
- three main types of population growth:
- exponetial, Arithmetic, Logistic
- explonetial growth
- constant rate per unit time
- arithmetic Growth
- increases at a consant amount per unit time
- Biotic Potential
- each species has a maximum level of reproductive output
- What can cause populations to fluctuate?
-
Intrinsic vs. extrinsic
abiotic vs. Biotic
Density dependant vs. Density independent - dieback
- populations crash when death rates exceed birth rates
- overshoot
- when population growth exceeds K of the environment
- natality
- production of new individuals
- fecundity
- ability to reproduce
- fertility
- number of offspring produced
- mortality
- emigration ( individuals removed from pop.)
- Life expectancy
- most likely age that is obtained
- life span
- max number of years
- Tolerance LImits
- minimum and max. environmental conditions that species can tolerate (temperature, oxygen level...etc)
- using tolerance to our advantage
- provides us with valuable environment indicators
- adaptation
- a change in anatomy or physiology that allws a species or population to live in a particular area
- 2 ways adaptation is used
- acclimation and population level changes in organisms
- 5 observations
-
tremendous fertility
stable populations
limited resources
variation
heritabiltiy - 3 inferences
-
struggle for existence
struggle not random
gradual change; character accumulate - What needs to be present for evolution to occur?
-
variety within a population
selective pressure
heritability - 2 ways speciation can occur
-
allopatric (found in different places)
sympatirc (found in same area) - Divergent evolution
- mutations and different selective pressures cause populations to evolve along dissimlar paths
- Convergent evolution
- when two different species evolve to look or funtion like one another
- law of competitive exclusion
- can only share resource for a short period of time
- Batesian mimicry
- harmless species evolve characteristics that mimic unpalatable or poisonour species
- Mullerian Mimicry
- 2 unpalatable species evolve to look alike
- intraspecific
- between members of same species
- interspecific
- between different species
- symbiosis
- 2 species live in close relationship
- commensalism
- one benefits, other is no affected
- mutualism
- both benefit
- parasitism
- one benefits one harmed
- primary succession
- colonizing; no species existed before
- secondary succession
- existing community changes
- climax community
- period of succession where little change occurs