Term
|
Definition
| study of interactions among organisms and their environments |
|
|
Term
|
Definition
| a group of organisms of the same species who live in a specific location and breed with one another more often than they breed with members of other populations |
|
|
Term
|
Definition
| total number of individuals in a population |
|
|
Term
|
Definition
| of a population, the number of individuals in each of several age categories |
|
|
Term
|
Definition
| of a population, the number of individuals who are of reproductive age or younger |
|
|
Term
|
Definition
| number of individuals per unit area |
|
|
Term
|
Definition
| type of environment in which a species typically lives |
|
|
Term
|
Definition
| where individuals are clumped, uniformly dispersed, or randomly dispersed in an area |
|
|
Term
|
Definition
| movement of individuals out of a population |
|
|
Term
|
Definition
| movement of individuals into a population |
|
|
Term
|
Definition
| interval in which births equal deaths |
|
|
Term
|
Definition
| A population grows by a fixed percentage in successive time intervals; the size of each increase is determined by the current population size |
|
|
Term
|
Definition
| Maximum possible population growth rate under optimal conditions |
|
|
Term
|
Definition
| a necessary resource, the depletion of which halts population growth |
|
|
Term
|
Definition
| Maximum number of individuals of a species that an environment can maintain |
|
|
Term
|
Definition
| A population grows slowly, then increases rapidly until it reaches carrying capacity and levels off |
|
|
Term
| Density-Independent Factor |
|
Definition
| Factor that limits population growth and arises regardless of population density |
|
|
Term
|
Definition
| Factor that limits population growth and has a greater effect in dense populations than in less dense ones |
|
|
Term
|
Definition
| A set of traits related to growth, survival, and reproduction such as age-specific mortality, life span, age at first reproduction and number of breeding events |
|
|
Term
|
Definition
Graph showing the decline in numbers of a cohort over time
(Cohort: a group of individuals born during the same time interval) |
|
|
Term
|
Definition
| A type I curve indicates survivorship is high until late in life. |
|
|
Term
|
Definition
| A type II curve indicates that death rates do not vary much with age. |
|
|
Term
| Type III Population Curve |
|
Definition
| A type III curve indicates that the death rate for a population peaks early in life. |
|
|
Term
|
Definition
| A curve on a graph that records the situation in which, in a new environment, the population density of an organism increases rapidly in an exponential or logarithmic form, but then stops abruptly as environmental resistance (e.g. seasonality) or some other factor (e.g. the end of the breeding phase) suddenly becomes effective. The actual rate of population change depends on the biotic potential and the population size. |
|
|
Term
|
Definition
| A pattern of growth in which, in a new environment, the population density of an organism increases slowly initially, in a positive acceleration phase; then increases rapidly approaching an exponential growth rate as in the J-shaped curve; but then declines in a negative acceleration phase until at zero growth rate the population stabilizes. This slowing of the rate of growth reflects increasing environmental resistance which becomes proportionately more important at higher population densities. This type of population growth is termed ‘densitydependent’ since growth rate depends on the numbers present in the population. |
|
|
Term
|
Definition
| All populations of all species that live in a particular region |
|
|
Term
|
Definition
| Organism that makes its own food using energy and simple raw materials from the environment; an autotroph |
|
|
Term
|
Definition
| Organism that gets energy and nutrients by feeding on tissues, wastes or remains of other organisms; a heterotroph |
|
|
Term
|
Definition
| All of a species' requirements and roles in an ecosystem |
|
|
Term
|
Definition
| Species interaction that benefits one species and neither helps nor harms the other |
|
|
Term
|
Definition
| Species interaction that benefits both species involved |
|
|
Term
|
Definition
| one species captures, kills and eats another |
|
|
Term
|
Definition
| Relationship in which one species withdraws nutrients from another species without immediately killing it |
|
|
Term
|
Definition
| One species lives in or on another in a commensal, mutualistic, or parasitic relationship |
|
|
Term
| Intraspecific Competition |
|
Definition
| Competition between the members of the same species |
|
|
Term
| Interspecific Competition |
|
Definition
| Competition between two species |
|
|
Term
|
Definition
| Process whereby two species compete for a limiting resource, and one drives the other to local extinction |
|
|
Term
|
Definition
| Species become adapted in different ways to access different portions of a limited resource; allows species with similar needs to coexist |
|
|
Term
|
Definition
| An animal that naturally preys on others |
|
|
Term
|
Definition
| An animal hunted and killed by another for food |
|
|
Term
|
Definition
| An organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense |
|
|
Term
|
Definition
| An organism that is infected with or is fed upon by a parasitic or pathogenic organism |
|
|
Term
|
Definition
| the gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established |
|
|
Term
|
Definition
| Species that can colonize a new habitat |
|
|
Term
|
Definition
| a biological community of plants and animals which, through the process of ecological succession — the development of vegetation in an area over time — has reached a steady state. This equilibrium occurs because the climax community is composed of species best adapted to average conditions in that area |
|
|
Term
|
Definition
| A new community becomes established in an area where there was no soil |
|
|
Term
|
Definition
| A new community develops in a site where the soil supported an old community remains |
|
|
Term
|
Definition
| Organism that makes its own food using carbon from inorganic molecules such as CO2 and energy from the environment; a producer |
|
|
Term
|
Definition
| In an ecosystem, an organism that captures energy from an inorganic source and stores it as biomass; first trophic level |
|
|
Term
|
Definition
| Organism that obtains energy and carbon from organic compounds assembled by other organisms; a consumer |
|
|
Term
|
Definition
| Position of an organism in a food chain |
|
|
Term
|
Definition
| Description of who eats whom in one path of energy in an ecosystem |
|
|
Term
|
Definition
| Set of cross-connecting food chains |
|
|
Term
|
Definition
| the production of organic compounds from atmospheric or aquatic carbon dioxide, principally through the process of photosynthesis, with chemosynthesis being much less important. Almost all life on earth is directly or indirectly reliant on primary production. The organisms responsible for primary production are known as primary producers or autotrophs, and form the base of the food chain |
|
|
Term
|
Definition
| Food chain in which energy is transferred from producers to grazers (herbivores) |
|
|
Term
|
Definition
| An animal that feeds on plants |
|
|
Term
|
Definition
| an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging. |
|
|
Term
|
Definition
| Food chain in which energy is transferred directly from producers to detritivores |
|
|
Term
|
Definition
| Consumer that feeds on small bits of organic material |
|
|
Term
Ecological Pyramids
(Trophic Pyramid or Energy Pyramid) |
|
Definition
| A graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem. |
|
|
Term
|
Definition
| Biomass pyramids show how much biomass is present in the organisms at each trophic level |
|
|
Term
|
Definition
| Movement of a chemical pollutant becomes increasingly concentrated as it moves up through food chains |
|
|
Term
|
Definition
| Species that eat both plant and animals |
|
|
Term
|
Definition
| Movement of phosphorous among Earth's rocks and waters, and into and out of food webs |
|
|
Term
|
Definition
| Movement of carbon, mainly between the oceans, atmospheres, and living organisms |
|
|
Term
|
Definition
| Warming of Earth's lower atmosphere and surface as a result of heat trapped by greenhouse gases |
|
|
Term
|
Definition
| A gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants |
|
|
Term
|
Definition
| Movement of nitrogen among the atmosphere, soil, and water and into and out of food webs |
|
|
Term
|
Definition
| A community interacting within in its environment |
|
|
Term
|
Definition
| the process by which organic material is broken down into simpler forms of matter. |
|
|
Term
|
Definition
| One of several processes by which new species arise |
|
|
Term
|
Definition
| A type of organism. Designated by genus name together with specific epithet |
|
|
Term
|
Definition
| The movement of alleles into and out of a population |
|
|
Term
|
Definition
| the process in which two or more populations of an ancestral species accumulate independent genetic changes (mutations) through time, often after the populations have become reproductively isolated for some period of time |
|
|
Term
| Reproductive Isolating Mechanisms |
|
Definition
| Refers to the end of gene flow between populations. It is part of the process by which reproducing species attain and maintain their separate identities. By preventing successful interbreeding, reproductive isolation reinforces differences |
|
|
Term
|
Definition
| If pollination or mating cannot occur or if zygotes cannot form |
|
|
Term
|
Definition
| Behavorial differences can stop gene flow between related species. |
|
|
Term
|
Definition
| Some populations cannot interbreed because the timing of their reproduction differs. |
|
|
Term
|
Definition
| In some cases, the size or shape of an individual's reproductive parts prevent it from mating with members of another population. |
|
|
Term
|
Definition
| Populations adapted to different microenvironments in the same region may be ecologically isolated. |
|
|
Term
|
Definition
| Even if gametes of different species do meet up, they often have molecular incompatibilities that prevent them from fusing. |
|
|
Term
|
Definition
| If hybrids form but are unfit or infertile. |
|
|
Term
|
Definition
| Speciation pattern in which a physical barrier that separates members of a population ends gene flow between them |
|
|
Term
|
Definition
| A physical barrier separates two populations and ends gene flow between them |
|
|
Term
|
Definition
| Pattern in which speciation occurs in the absence of a physical barrier |
|
|
Term
|
Definition
| Speciation model in which different selection pressures lead to divergences within a single population |
|
|
Term
|
Definition
| an evolutionary splitting event in a species in which each branch and its smaller branches forms a "clade", an evolutionary mechanism and a process of adaptive evolution that leads to the development of a greater variety of sister species |
|
|
Term
|
Definition
| the evolution of species involving an entire population rather than a branching event |
|
|
Term
|
Definition
| Type of diagram that summarizes evolutionary relationships among clades |
|
|
Term
|
Definition
| A burst of genetic divergences from a lineage gives rise to many new species |
|
|
Term
|
Definition
| refers to a species that has been permanently lost |
|
|
Term
|
Definition
| simultaneous loss of many lineages from Earth |
|
|
Term
|
Definition
| Species are groups of interbreeding natural populations that are reproductively isolated from other such groups. |
|
|
