Ecology Unknowns (ft: darkness and mystery) Flashcards
What is ecology ?
The study of the interactions between living organisms and their environment
What is the biosphere?
All living things on the planet ie: global ecosystem
What is the modern synthesis theory?
Diversity arises from mutation which creates phenotypes of which the environment selects for with the highest fitness
What acts as a tool for natural selection?
- variation in phenotypes is the tool which NS uses or acts upon for evolution
Does NS evolve individuals?
NO. Natural selection acts on individual variation but evolves populations over time.
What is the phylogenetic species concept?
- species are defined based on common ancestry and phylogenetic similarity
What is behaviour? What are the degrees of study of behaviour in biology?
- Behaviour is the visible response to internal or external stimuli
- ethology: field of study related to behaviour
- sociobiology: the branch of biology that studies behaviour
- behavioural ecology: studies interactions between organisms and their environment: the interactions between organisms and their environment are mediated by behaviour
What is kin selection?
- an evolutionary strategy that favours the fitness of those related to an organism over their own fitness
- ensures the survival of genes!
What is group selection?
- where the betterment of the group is favoured over the individuals fitness
- causes them to sacrifice for their group eg; pika alarm call
How did altruism arise?
- from group selection
How did eusociality arise?
Potentially kin selection or ecological restraints
NOTE: kin selection: in leaf cutter ants, workers are more related than their offspring, so they may work better together as a product of evolutionary strategies to ensure the survival of their own genes (the other workers)
Which species has the greatest variety of life histories?
fish
What is life history?
- the pattern of survival and reproduction of a species
What is fecundity?
the amount of offspring/ability to create viable offspring
What are graminoids?
- grass and grass like plants
What are forbs?
- non-graminoid herbaceous plants, persist for one growing season, little to no woody tissue
What are the two factors that influence plant distribution? What about selective pressures?
- distribution: plant growth and seed dispersal
- selective pressures: intensity of stress and intensity of disturbance
Define semelparous
- when organisms reproduce only one time in their lives, occurs in stable environments, parent can dedicate all energy to their offspring
- common in insects but some others like salmon
Define iteroporous
- in organisms whose offspring have low survival rate, individuals will have longer, more frequent breeding periods to ensure the survival of at least some offspring
- common in vertebrates and k selected species
What are the 3 main methods of estimation?
- cohort life table: find others born at same time and track from birth
- static life table: record age at death
- age distribution: track population between age gaps, differences attributed to death
What are life tables for?
- a record of survival and reproduction rates, provides survival curves
Why are survival curves important?
- fundamental descriptors of a population
How can coexistence occur despite the competitive exclusion principle?
- competitive equivalence
- environmental heterogeneity impacts competitive strength
- variation in competitive ability within species
When can coexistence occur?
- when k1< K2/impact of 2 on1
and vice versa - K must be similar between species
- each species must be regulated by its own carrying capacity to exist
What were the first studies of variation on?
-plants
What are the 8 main interactions?
What are the 4 social interactions?
9: mutualism, ammenalism, commensalism, competition, predation/herbivory/parasitism, neutralism
4: altruism, spitefulness, selfishness, mutualism
What are castes?
- different groups with certain roles based on different morphological characteristics
- leaf cutter ants have the greatest amount of castes and therefore the greatest amount behaviours
describe the relationship between darter size and egg size
- larger darter produce more eggs
- the more eggs there are the smaller they get
What inhibits the kangaroos from living in the north?
- temperature and precipitation, eavronemtnal conditions limit the distribution of roos
Which two assumptions does exponential growth make?
- unlimited resources
- stable environment (ensure birth and death are equal, r growth rate is fully realized)
- BUT in the real world conditions vary and resources are limited (logistic)
What is resource partitioning?
- multiple species can use the same resource in a slightly different way or at different times so they can coexist ; one does not outcompete the other
What can be said about the experiment on potentilla glandulosa?
Different populations of the same species were taken from different elevations
- if they were genetically identical, they would all grow the same
- genetic variation present, grows differently in the same plot
this demonstrates that populations are locally adapted and genetically distinct (populations have evolved independently, ecotypes)
Does Natural selection always favour the fixation of a phenotype?
No! Natural selection can favour, disfavour or maintain the genetic makeup of a population
Does evolution work on individuals?
- NO, natural selection works on individuals while evolution works on populations
Describe the honey bee example
- demonstrates that behaviour can be selected for
- in honey bees, a single gene determine whether a bee is a forage or a hive worker: determine by environmental conditions
What is the difference between group selection and kin selection?
kin- sacrifice for relatives
group -sacrifice for social group
Describe the lion prides
- females closely related, protect infants and each other = kin selection
- males not always related: kin selection not an adequate description: group selection when they protect social groups
- but sometimes they kill younger males (females must protect them) so this is where selfish behaviour is favoured over altruism
What is the relationship between relation and male coalition size?
- smaller coalitions often have more relatedness whereas larger coalitions of males are typically unrelated ( must have offspring to increase fitness)
What is the difference between disturbance and stress?
disturbance: anything that. destroys biomass (storms, avalanches, fires, etc)
Stress : anything that limits the production pf dry biomass (limited nutrients, drought, etc)
What are the benefits of community ecology?
- bridge between physiological and community ecology
- helps us develop recovery plans and regulate invasive species
Why might phylogenetic species concepts become more common over the coming decade ?
- more focus on microbial organisms and increased availability of molecular methods
How do ruderals respond to stress?
Ruderals do better in areas of high disturbance but cannot handle stress
(stress tolerant cannot handle disturbance ie: oak tree falls during storm)
