Intro to Ecology Flashcards

extinction

when the last living individual of a species dies

conservation biology

a multidisciplinary science focusing on the preservation of Earth’s biodiversity.

extinction crisis

the rapid increase in extinction rates caused by humans becoming the dominant species on Earth

speciation

the splitting of one species into two distinct species

biogeography

the study of the geographical distribution of species

eukaryotes

organisms characterized by cells with a clearly defined, membrane-bound nucleus

species richness

the number of species in a specified area

equator

an imaginary line that is located equidistant from the two poles and which divides the planet into the Northern and Southern Hemipheres

latitude

a location’s angular distance north or south of the equator

biota

all of the living organisms within an ecosystem, including plants, animals, bacteria, and fungi

Buffon’s Law

despite having similar climates, different regions of the globe frequently have distinct biotas

terrestrial species

a species that lives on land

biogeographic realm

the first tier of a classification scheme that divides Earth’s landscape into broad geographic areas based on the phylogenetic relationships of their biota

biogeographic region

the second tier of a classification scheme that divides Earth’s landscape into broad geographic areas based on the phylogenetic relationships of their biota

endemism

the restriction of the occurrence of species to a defined geographic area or local region, or the abundance of endemic species within a specified location

ecological biogeography

the study of the factors that determine current species distributions and the composition of extant biotas, focusing both on interactions among organisms and on interactions between organisms and their abiotic environment

historical biogeography

the study of how evolutionary lineages affect current and historic distributions of species and biotas, paying particular attention to the roles played by speciation, extinction, and dispersal

dispersal

an ecological process by which organisms move from one place of residence to another

alpha diversity

local diversity, the number of species found in a specific, relatively homogenous site

beta diversity

species turnover, the change in species composition over relatively short distances

gamma diversity

regional diversity, the number of species in a comparatively broad geographic region ranging from a group of local communities to biomes, continents or ocean basins

sessile organism

an organism that cannot move from its current location in physical space

epifauna

fresh and salt-water animals that live on the surface of a substrate such as the sea floor, rocks, pilings, or even other organisms

destructive sampling

approaches where organisms are destroyed or killed during the process of sampling

nondestructive sampling

approaches where the samples are left in place

sampling error

caused when measurements are made from a sample instead of an entire population, resulting in the data becoming biased toward that sample

experimental  error

includes all deviations from the true value of interest that are not caused by sampling error

randomization

the placing of members of a set in random order

asymptote

a line that is drawn so that the distance between a curve and the line approaches zero as the curve approaches infinity

hypothesis

a proposed explanation for observed phenomena

interspecific

distinguishes interactions or differences that occur between species

generalist

a species that takes advantage of a wide variety of environment conditions

specialist

species whose environmental and dietary requirements are restrictive

niche

the constellation of environmental conditions under which a species can survive

IUCN Red List

a list of species and their conservation status

threatened species

a species that is in danger of going extinct

climate change

a significant and persistent change in the measures of climate

exotic species

a species that humans have accidentally or intentionally introduced to a biologic community from another location

ecosystem services

benefits humans receive from ecosystems

species richness

the number of species in a specified area

species accumulation curve

a plot of cumulative number of species found in a defined area

sampling effort

a measure of the effort made when sampling a population or community

Species Area Equation

S=cA^z, where S is the number of species on the island, A is the area of the island, and c and z are constants specific to taxa and place, determined by fitting a curve to the species area data

population rescue

when a population might go extinct on its own, but immigrants join the population and prevent it

equilibirium theory of island biogeography

theory by E.O. Wilson and Rober MacArthur which proposes that immigration and extinction rates determine the equilibrium species richness found on an island

equilibrium species richness

the number of species found on an island when immigration and extinction rates are equal

evolution

change in frequencies of alleles across generations or between populations

community

the association of species within a defined area that actually or potentially interact with each other

equilibrium

a system that experiences no net change or movement in the quantity of interest

patch

a distinct area or habitat for a type of organism

corridor

a route, often narrowly defined, that nearly all members of a taxon can easily traverse

filter

disperal pathway that tends to selectively prevent some species from passing while allowing others through

sweepstakes route

a dispersal pathway that is nearly impossible for a species to cross except during rare and unpredictable circumstances

jump dispersal

a long-distance dispersal between two habitat patches that is accomplished relatively quickly, often in a single bound

diffusion

refers to range expansion that is accomplished over many generations as individuals on the margins of a species range’ expand into unoccupied habitat.

secular migration

species’ range expansion that occurs over many, many generations and which takes so long that the species evolve en route, with populations adapting via natural selection to new environments they encounter as they move across the landscape

reserve

an area of land or ocean that has been granted some degree of protection from human activities.

tectonic plate

a stiff, irregularly shaped slab of solid rock which is part of the Earth’s crust

allopatric speciation

speciation initiated when two populations of the same species become geographically isolated, either as a result of vicariance or of dispersal

population

a group of individuals of one species who live in the same area at the same time

genetic drift

the change in the genetic composition from generation to generation that happens as a result of sampling error.

vicariance

the splitting of one contiguous population into two or more ranges, and often results from geologic events

founder event

the initial colonization of a new habitat by a few “founding” individuals

sympatric speciation

a process by which two groups of a population become reproductively isolated

Great American Biotic Interchange

the exchange of terrestrial fauna and flora between North and South America that resulted from the emergence of the Isthmus of Panama about 3.5 million years ago

Isthmus of Panama

the land bridge connecting North and South America

biodiversity hotspot

area of extraordinary conservation value

solar radiation

the electromagnetic radiation emitted by the sun

hadley cell

a type of atmospheric circulation cell that is driven by the heating of the Earth’s surface at the equator

Coriolis effect

the apparent deflection of objects moving across a rotating sphere

biome

a large-scale contiguous area that experiences similar climatic conditions throughout, and is characterized by resident biota that distinguish it from surrounding areas

life cycle

the series of stages an organism goes through in its lifetime

life history

the sequence, timing, and natures of events in an organism’s life

life history trait

a heritable trait that determines some aspect of the life history of an organism or species

life history strategy

a pattern of life history traits that has evolved by natural selection over time in a population in response to particular ecological and environmental conditions

constraint

A limitation on the possible types of life history that a species can have

fecundity

the potential reproductive capacity of an individual organism or population

trade-off

a constraint that prevents the fitness contribution of two different traits from being maximized at the same time

demographic parameters

quantitative values that characterize the life history of a species

per capita population growth rate

the net rate at which a population is increasing (or decreasing) over time per individual already in the population

age structure

the distribution of ages within a population

age pyramid

a graphical way to show the age structure of a population

life table

a table that summarizes demographic parameters for a species or population, listed by age class

age class

a group of individuals in a population that are a particular age

survivorship

the proportion of a cohort of individuals that survives to a given age class

survivorship curve

a graph that plots age class on the x-axis and survivorship on the y-axis

mortality

the number of deaths per unit time occurring within a population

age specific fecundity

a demographic parameter that characterizes fecundity at a particular age, usually for females.

net reproductive rate

the average number of female offspring that each female in a population has over her lifetime

generation time

the average amount of time from the birth of a female until the birth of her daughters

demographic transition

a historical phenomenon of human populations, during which a particular pattern of large-scale change occurs

behavior

the manner in which an organism interacts with its environment, members of its own species, and members of other species

ontogeny

the sequence of events in the development of an individual organism, from origin to maturation

adaptive value

the extent to which an adaptation improves the evolutionary fitness of an individual

phylogeny

the evolutionary history and relationships among or within groups of organisms

behavioral ecology

the study of the evolutionary basis of behavior, focusing on the causes of variation within populations and between species

optimality theory

a theory that asserts that evolution has favored behaviors that are, in some way, optimal

model

a simplified representation of reality

currency

a variable that is expected to be correlated with fitness

central place foraging

describes a foraging strategy typical of animals that repeatedly venture out from a central place or nest to forage and then return to consume or cache their food