Revised exam

• Genes and the environment are causes in variation in phenotype within the same species
• Quantitative traits are continuous traits generated by many genes if small effect
• Polyphenism are several distinct phenotypes on the same genetic background
• The six types of interactions are Commensalism, Mutualism, Territoriality, Parasitism, Predation, and competition
• habitat sustainability can limit distribution and abundance
• patchy distributions indicate that a habitat is not well suited for a species even though it is within the species geological range
• the three types of dispersal are cluster, regular, and random
• Small populations tend to go extinct due to these three ecological reasons: Natural catastrophes, Demographic stochasticity, and environmental stochasticity
• Demographic stochasticity is where birth and death rates are constant but the actual fates of individuals differ due to random nature of whether they will reproduce/survive
• Environmental stochasticity is where the average birth and death rate is constant but the birth and death rates differ from year to year
• emigrants > immigrants means it is a source
• immigrants > emigrants means it is a sink
• a community is a group of potentially interacting populations of different species
• three examples of victim exploiter interactions: predator-prey, herbivore-plant, and parasite-host
• Food, water, and light are resources that are consumed
• space and light are resources that are depleted
• Competition can increase in intensity and can become more negative when resources are scarce
• competition can limit distribution and abundance
• the Competitive exclusion principle is when Two species that use limiting resources in the same way cannot co-exist indefinitely
• Some adaptations prey have that reduce their chances of being killed are armor, crypsis, mimicry, refuge, size, speed, and toxins
• Exploitation that leads to increased production of the defense is called inducible defenses
• some adaptations predators have evolved to overcome defences: behavior, claws, detoxification, jaws, sensory systems, size, speed, and toxins.
• Necessary mutualistic interactions are obligate
• interaction where one could survive without the mutualism of the other facultative
• When The squid screens luminescent bacteria from non-luminescent ones, by imposing a strategic cost its is called screening
• Species that involve mutualistic interactions between many species are called generalists
• Species that involve mutualistic interactions between only one species are called specialists
• a mutualist receives energy or nutrients from its partner is called trophic mutualism
• a mutualist receives shelter, a place to live, or favorable habitat is called habitat mutualism
• Imagine a copepod feeding on diatoms. This material is ingested and some is used to create new cells or tissues, a process called assimilation
• trophic cascades occur when predators limit the density and/or behavior of their prey and thereby enhance survival of the next lower trophic level
• species composition changing through time following disturbance is also known as temporal succession
• The final stage in succession is called the climax community
• the Intermediate disturbance hypothesis is when diversity is higher at an intermediate frequency of succession, than at an infrequent and large or infrequent and small.
• Differing arrangements of an ecosystem's characteristics, such as its functions, processes, components, and interrelationships is called Alternative stable states
• the boarders between ASS are called threshholds of change or tipping points
• Regime shifts are the transitin fro one stable state to another
• regime shifts can be caused by internal feedback or external disturbance
• Having arrived at one state may make it hard to go back to another state is called hysteresis
• Competition occurs between individuals that share the use of a resource that limits their survival, growth or reproduction


  When grown alone, each diatom species reduced silica concentrations to low levels and reached a stable population size