Lecture 1 Ecology Flashcards
hierarchy of scale
organism population community ecosystem biosphere
population
group of individuals of same species in a given area that have potential to interbreed and interact
community
assemblage of interacting species living together at same place and time
ecosystem
biological community together with physical environment
landscapes
geographic area that includes multiple ecosystems
biosphere
all living organisms on earth plus respective environments
Biological population
group of individuals of same species in a given area that have potential to interbreed and interact
Statistical population
individuals within specified time or space about which inferences are to be made (potential sampling units)
metapopulation
group of geographically isolated populations linked by dispersal (migration)
endemic species
only occurs in 1 particular geographic location
E.g. Edith’s checkerspot butterfly
ecological theory
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
species
• Same species if - individuals capable of breeding, freely exchanging genetic material and producing fertile offspring
biological species concept
species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups
ecological species concept
a group of individuals adapted to a particular niche
species identification
morphology and physiology
Behaviour (animals)
Molecular biology (DNA sequencing)
Cell Biology (e.g. chromosome shape)
Ecology (spatial and temporal. Abiotic and biotic interactions)
Biodiversity
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
Evolution - natural selection (Mechanism for evolutionary change)
- Reproduction produces more offspring than can survive - substantial mortality
- Individuals within species vary in ability to survive and reproduce
- Offspring inherit characteristics from parents that affect their survival and reproduction
evolution … ??
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
adaptation
morphology, physiology and behaviour
Body plan
Respiration - gas exchange & circulation
Osmoregulation & excretion
Communication
Locomotion and support
Attachment to substrate
Feeding mechanisms
Life history
Reproduction
Dispersal
adaptation abiotic interactions (physical env)
Temperature
Radiation
Moisture
Gas balance
Soil and water chemistry
pH
Salinity
Substrate
Soil structure
Current flow
adaptation
biotic interactions
Competition
Commensalism
Mutualism
Predation
Succession
adaptation
resources = competition
Water Gases (O2 CO2) Energy (radiation) Food Inorganic nutrients Space Shelter Mates
Autotrophic organisms
Plants, algae, some bacteria
Photosynthesis or chemosynthesis
Radiation
CO2
Water
Mineral nutrients
Heterotrophic organisms
Animals fungi bacteria
Predators, parasites, decomposers
Organic material (plant, animal, bacteria)
interactions/competition
Intraspecific - same species
Individuals of same species have similar niches
Interspecific - different species
Individuals of different species usually have distinct niches
Niche overlap = competition
Niche
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
Niche
competitive exclusion principle (gauses law)
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)
fundamental niche
Overall potential of a species
Widest range of conditions a population could occupy in absence of competition
realised niche
Smaller niche that a population actually occupies due to competition and predation
niche
n-dimensional hypervolume
Species survive in multidimensional space where each environmental or biotic limiting factor is an axis
