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56 Cards in this Set

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3 conditions necessary for evolution by natural selection

1. variability

2. heritability of characteristics

3. influence of the environment on survival and reproduction


Speciation: appearance of a new species

Speciation event occurs in:

Allopatry 2nd pop must be seperated in space

not in sympatry


changes that occur in a pop, that do not lead to a new spp

(e.g. resistance to insectizides)


characteristic is not heritable


a commulative change in the characteristics of one population of organisms over time

3 evolution processes

1. Variation

2. Reproduction

3. Natural selection


feature of an organism that increases fitness (survival and reproduction)


the proportional distribution of individuals to future generations

3 types of selection

1. Directional selection

2. Stabilizing selection

3. Disruptive selection

Adaptive radiation

evolution of 1 generalised ancestral species to many specialised descendants

Environment includes

1. physical factors

2. chemical factors (nutrients)

3. Biological factors (spp)

Natural selection

an individual behaviour that max. the net benefit

Territorial defense (cost + benefit)

cost: time, energy, risk of injury

benefit: food, mate, shelter

Group living

+ mating success, vigilance

- less resources, diseases, predation risk


closly related, stay together, recognize relatives

sterile individuals - altruistic

biotic interactions

abiotic factors

predators, parasites, competitors

temperature, physiological ecology


pattern in space and time


moment of individuals into a new area to survive and reproduce

Gene flow

movement of alleles from one pop to another

3 modes of dispersal

1. Diffusion (california otter, cane toad)

2. Jump dispersal (African honey bee)

3. Secular (occurs in evolutionary time)

dispersal barrier

not always geogr. range


part of the biosphere where a specific species can live

strategies to escape competition

1. selecting different part of the habitat

2. changing diet

Abiotic factors that limit distribution

1. temperature and moisture

2. light, pH, chemical factors


a group of organims of a same species, occupying a particular space at the same time

Local population

Individuals sharing the same gene pool

2 types of population

1. Unitary: Organism in pop: individual units (cats, birds)

2. Modular: not individual (coral, grass)

4 parameters of pop

1. Natality

2. Mortality

3. Immigration

4. Emigration

survivorship curves

1. large mammals, humans in developed countries

2. hydra, lizard, bird, mouse

3. fish, marine organims, oysters, oak trees, frog

Expanding pop formular

Nt = N0*e^(r*t)

Discrete generation

no overlapping between parent generation and further generation, life cycle on year

Pop. depends on R0, if <1 then extinction

Biological interactions classification

1. mechanisms of the interaction

2. effects of interaction

Biological interaction: mechanisms

1. Competition

2. Predation

3. Herbivory

4. Parasitism

5. Disease

6. Mutualism

Categories effects of biological interaction

1. 0 no effect

2. + one pop benefited at the expense of the other

3. - one pop adversely affected by the other


1. Resource competition: common resource, short supply

2. Interference competition: seeking of a resource harms other organisms


Plans: light, nutrients, water, pollinators, space

Animals: water, food, mates, space


ecological space occupied by a species + the occupation of the species in a community

Fundamental niche

ecological space occupied by a species in the absence of competition and other biotic interactions from other species

realised niche

the observed resource use of a spcies in the presence of competition and other biotic interactions; contrast with fundamental niche

Anti-predator defense

1. Colouring (but predators must sample)


any assemblages of pop of living organisms in a prescribed area or habitat

community structure

1. temporal variation (succession)

2. spatial variation (biodiversity)

Succession types

Primary succession - new sterile area (lava, glacier, sand dunes)
Secondary succession - recovery from disturbed sites (flood, hurricane, tornado, fire)

Concepts of succession: Facilitation model

1. species replaces each other, modify the environment --> less suitable for them, more suitable for others

Concepts of succession: Inhibition model

initial floristic composition depends on who get to the area first

each species surpresses and excludes new colonists

more individualistic, less predictable

Concepts of succession: Tolerance model

any spp can start succession, more tolerant to limiting resources, replace others, superior spp --> will dominate

Concepts of succession: random colonisation model

only chance survival of a spp

no facilitation, no competition

can move in any direction


Spatial variation of community structure

Biodiversity can be measured at:

1. Genetic level

2. Species level

3. Ecosystem level

Species richness

Count all species:

Shannon Wiener Index

high when no of species high, or even distribution

Simpsons Index

little weight to rare species

endemic species

spp occur only in a relatively small geographic area

umbrella species

serve as a guide to other groups of species

protecting them indirectly protects others

factors that have influence on biodiversity

evolutionary speed

geogr. area

interspecific interactions

ambient energy