Population Ecology and Community Interactions Flashcards

Vocabulary terms and definitions covering population dynamics, survivorship curves, and community ecology as discussed in the lecture notes.

Type III survivorship

A pattern characterized by higher offspring production where many die quickly, but the remaining offspring survive (e.g., trees, insects, and ticks).

$r/K$ selected species

Natural selection that selects a population to increase within an environment.

$$r$$

The intrinsic rate of increase, which measures how quickly a population can replicate itself (e.g., $2$ equals double, $3$ equals triple).

$$K$$

Carrying capacity; the number of individuals in a population that can be sustained by the resource in the habitat where the population resides.

$$r > 0$$

Indicates the population is increasing.

$$r < 0$$

Indicates the population is decreasing.

$$r = 0$$

Indicates the population size remains the same.

$$N = K$$

Condition where there is no change in population; it remains the same.

$$N > K$$

Condition where the population will "die out" or modify reproductive habits to keep $K$ constant.

$$N < K$$

Condition where the population increases to keep $K$ constant.

r-selected species

Species characterized by lots of small offspring, shorter lifespans, little or no parental care, and early maturation; they tend to live in unpredictable environments with limited resources.

K-selected species

Species characterized by longer lifespans, few larger offspring, later maturation, and more parental care; they evolve in predictable and fairly stable environments.

Exponential growth

A growth curve represented by a “J” shape, notably seen in the world population after deaths decreased in the 1900s due to antibiotics and sanitary improvements.

Logistics Growth

A growth curve represented by an “S” shape.

Virulence of Lyme disease

Increases when the mouth piece of ticks pierces the skin of their host, allowing more of the pathogen to enter the bloodstream.

Community

All of the living organisms inhabiting a particular area that depend on each other and involve interactions at all levels.

Resource partitioning

The result of two species competing.

Symbiotic relationship

A close interaction with one another over a given time where organisms live together; predator-prey is specifically not a type of this relationship.

Commensalism

A relationship where one organism benefits and the other is unaffected (e.g., birds and squirrels in trees, or $Borrelia \, budgefori$ in ticks).

Mutualism

A relationship where both organisms benefit (e.g., bees and flowers, cleaner fish and sharks, or coral and algae).

Parasitism

A relationship where one organism benefits and the other is harmed (e.g., tapeworms, lice, flees, bedbugs, or disease-causing pathogens).