Lecture 1 Ecology

Question 1

hierarchy of scale

Answer 1

organism 
population 
community 
ecosystem 
biosphere

Question 2

population

Answer 2

group of individuals of same species in a given area that have potential to interbreed and interact

Question 3

community

Answer 3

assemblage of interacting species living together at same place and time

Question 4

ecosystem

Answer 4

biological community together with physical environment

Question 5

landscapes

Answer 5

geographic area that includes multiple ecosystems

Question 6

biosphere

Answer 6

all living organisms on earth plus respective environments

Question 7

Biological population

Answer 7

group of individuals of same species in a given area that have potential to interbreed and interact

Question 8

Statistical population

Answer 8

individuals within specified time or space about which inferences are to be made (potential sampling units)

Question 9

metapopulation

Answer 9

group of geographically isolated populations linked by dispersal (migration)

Question 10

endemic species

Answer 10

only occurs in 1 particular geographic location

E.g. Edith’s checkerspot butterfly

Question 11

ecological theory

Answer 11

The study of ecology has different levels

Biosphere: global cycles and processes

Ecosystem: energy flux and nutrient cycles

Community: interspecific interactions

Population: intraspecific interactions, population dynamics, unit of evolution

Organism: survival and reproduction, unit of natural selection

Question 12

species

Answer 12

• Same species if - individuals capable of breeding, freely exchanging genetic material and producing fertile offspring

Question 13

biological species concept

Answer 13

species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups

Question 14

ecological species concept

Answer 14

a group of individuals adapted to a particular niche

Question 15

species identification

Answer 15

morphology and physiology

Behaviour (animals)

Molecular biology (DNA sequencing)

Cell Biology (e.g. chromosome shape)

Ecology (spatial and temporal. Abiotic and biotic interactions)

Question 16

Biodiversity

Answer 16

Ecosystem diversity - landscape / habitat

Species diversity - variation between species

Phenotypic (morphology) diversity - variation between individuals and populations within a species

Genetic diversity - variation in gene that code for observable variation

Question 17

Evolution - natural selection (Mechanism for evolutionary change)

Answer 17

1. Reproduction produces more offspring than can survive - substantial mortality
2. Individuals within species vary in ability to survive and reproduce
3. Offspring inherit characteristics from parents that affect their survival and reproduction

Question 18

evolution … ??

Answer 18

Factors enhancing reproduction must be favoured by natural selection to produce adaptive evolutionary change across generations and through time

Variation within & between species a result of NS

Better adapted individuals more likely to survive reproduce and pass on genes

Some individuals in a species better adapted to where and how they live that others

Depends on interactions between characteristics of individual and its environment (ecology)

Populations have potential to populate whole earth but limited by adaptation to environment

Question 19

adaptation

morphology, physiology and behaviour

Answer 19

Body plan

Respiration - gas exchange & circulation

Osmoregulation & excretion

Communication

Locomotion and support

Attachment to substrate

Feeding mechanisms

Life history

Reproduction

Dispersal

Question 20

adaptation 
abiotic interactions (physical env)

Answer 20

Temperature

Radiation

Moisture

Gas balance

Soil and water chemistry

pH

Salinity

Substrate

Soil structure

Current flow

Question 21

adaptation

biotic interactions

Answer 21

Competition

Commensalism

Mutualism

Predation

Succession

Question 22

adaptation

resources = competition

Answer 22

Water 
Gases (O2 CO2)
Energy (radiation)
Food 
Inorganic nutrients 
Space 
Shelter 
Mates

Question 23

Autotrophic organisms

Answer 23

Plants, algae, some bacteria

Photosynthesis or chemosynthesis

Radiation

CO2

Water

Mineral nutrients

Question 24

Heterotrophic organisms

Answer 24

Animals fungi bacteria

Predators, parasites, decomposers

Organic material (plant, animal, bacteria)

Question 25

interactions/competition

Answer 25

Intraspecific - same species

Individuals of same species have similar niches

Interspecific - different species

Individuals of different species usually have distinct niches

Niche overlap = competition

Question 26

Niche

Answer 26

functional position and role of an organism in its environment

Habitat it lives in

Resources it uses

Activity in space and time

Abiotic and biotic interactions

Question 27

Niche

competitive exclusion principle (gauses law)

Answer 27

Complete competitors cant coexist

2 species with similar ecology competing for same resources cant coexist if other factors constant

One competitor with an adaptive advantage will outcompete the other and eliminate it or force an evolutionary shift to different niche

(competition for resources drives adaptation to niche)

Question 28

fundamental niche

Answer 28

Overall potential of a species

Widest range of conditions a population could occupy in absence of competition

Question 29

realised niche

Answer 29

Smaller niche that a population actually occupies due to competition and predation

Question 30

niche

n-dimensional hypervolume

Answer 30

Species survive in multidimensional space where each environmental or biotic limiting factor is an axis