Midterm 2 Key terms Flashcards
What is allopatric speciation
species that are spilt due to a geographical barrier or movement
What is sympatic speciation?
species that are spilt by reproductive separation even though they are in the same place (separated by time or reproductive cycles/mating seasons)
What is endemism?
Refers to species evolving in a certain region and staying in that region
What is range expansion?
The evolution of a species elsewhere (nearby) and then expanded its range to also include another area
What is range shift?
the evolution of a species that evolved elsewhere but its range shifted to not include the former distribution, only the current distribution
What is long-range dispersal?
Non-native/invasive, it arrived from somewhere else not nearby
What is Vicariance?
the evolution of a species somewhere under certain environmental conditions, but then the physical landscape itself moved, thus exposing those species to different environmental conditions or geographical barrier
What is niche partitioning?
the prevention of niche overlap, every species has some difference in the resource they use, how they impact the environment, etc.
True or False: 2 species with the same niche often coexist?
False; 2 species with the same niche can never coexist
What is species richness?
the number of species within a habitat
What is species diversity?
A combination of species richness and species eveness
What is species evenness?
relative abundance of each species in each area
What is the main difference between species richness/evenness and beta/gamma species diversity?
Species richness/evenness is measured within a habitat, beta/gamma species diversity is measured across a habitat or multiple habitats
On a local scale, how do we know when enough plots have been sampled?
When the graph reaches a plateau/ when sampling is intensely saturated
What does the shannon diversity index indicate?
associated with species evenness, it represents how abundant each species is relative to the abundance of the other species in a given habitat
What is beta diversity?
measure of how different the diversity is between two habitats
What is gamma diversity?
the total number of species across all habitats being studied
What is alpha diversity?
the total number of species within a habitat
What is the fundamental niche?
all the possible dimensions in which a species can survive in principle
What is the realized niche?
the dimensions in which a species actually survives after the affects of biotic interactions
What is competitor exclusion?
when one competitor disappears or move out of the area
What is character displacement?
both species continue to co-exist, but they diverge to occupy slightly different niches within the shared habitat, this could be from
What is meant by co-existence at reduced carrying capacity?
both species continue to live in the area, but at lower numbers
What are the three spatial patterns of distribution?
clumped, even and random
True or False: Biotic interactions are only important in terms of defining biomes at large scales
True
What is the equation for population abundance?
Pt2 = Pt1 + (B-D) + (I-E)
What are density dependant factors?
they affect per capita birth or death rates in a way that depends on the population density
What are density independant factors?
they affect per capita birth or death rates in a way that DO NOT depend` on the population density
What are the possible reasons for why a species may live where they live?
endemism, vicariance, long-range/invasive, range shift, and range expansion
Can a density-dependent or density-independent treatment eradicate a population?
density-independent
Does density-dependent or density-independent treatment result in a lower carrying capacity?
density-dependent
What are two reasons why a species may occupy two different areas?
Vicariance and dispersal
How are biodiversity and latitude related?
inversely related
How are population size and latitude related?
proportionally related
True or Flase: when the number of all individuals within a habitat is doubled, the shannon diversity indices is also doubled
False; the shannon diversity index remains the same
What does a shannon diversity index greater than one mean?
the habitat is very even
What are some examples of density dependent factors?
disease, competition, parasites
What are some examples of density-independent factors?
temperature, flooding/storms, human activity
What is population ecology?
concerned with factors such as population size, density, growth and patterns of dispersion
What is community ecology?
the study of the structure and dynamics of animal and plant communities
What is commensalism species interactions?
when species 1 is benefited but species 2 is neither benefitted nor harmed
What is amensalism species interactions?
species 1 has a negative effects in species 2 but species 1 is neither benefited nor harmed
What is a functional trait?
how a species functions within a community or ecosystem
What are ecosystem engineers?
organisms that control the availability of resources to other species
What is the intermediate disturbance hypothesis?
predicts that the highest level of species richness will occur at an intermediate level of intensity or frequency of natural disturbance
