Test #2 Flashcards
Adaptation
Any heritable (may include behavior) trait that enables an organism to survive and reproduce better under environmental conditions through natural selection.
Natural Selection
Some individuals in a population have genetically-based traits that increase their chances of survival and ability to produce offspring with the same traits.
Critical Factor
The single factor in shortest supply relative to demand.
Tolerance Limits
Each environmental factor has both min and max levels beyond which a particular species cannot survive or is unable to produce.
Indicators (Indicator species)
Sometimes the requirement and tolerances of species are useful indicators of specific environmental characteristics. āBiological Smoke Alarms.ā
Habitat
The place/set of environmental conditions in which a particular organism lives.
Ecological Niche
Describes either the role played by a species in a biological community or the total set of environmental factors that determine a species distribution.
Endemic
(Species) Occur only in one area or one type of environment.
Competitive Exclusion Principle
No two species can occupy the same ecological niche at the some time. A more efficient one will win.
Resource Partitioning
Species can coexist in a habitat by utilizing different parts of a single resource.
Speciation
The development of new species.
Geographic Isolation (Allopatric Speciation)
When a subpopulation becomes seperated from the main population and can no longer share genes with it. The new population evolves independently of the first, creating a new species.
Sympatric Speciation
Organisms continue to live in the same place but become isolated by other means.
Binomials
Names composed by botanists, ecologists, and other scientists who often use the most specific levels of tree, genus, and species to compose these names.
Intraspecific Competition
Competition among members of the same species. Competition reduced if: young disperse, animal defends a territory, adults and juveniles occupy different niches.
Interspecific Competition
Competition between members of different species.
Predator-Mediated Competition
One species may be the best competitor in a given location, but predators may reduce its abundance and allow the weaker competitor to increase its numbers.
Coevolution
Changes in the gene pool of one species can lead to changes in the gene pool of another species in populations where the two species have interacted for a long time.
Mimicry
the action/art of intimidating something. The close resemblance of an animal or plant to another animal, plant, or inanimate object for protection.
Symbiosis
When interactions between organisms are nonantagonistic (Even beneficial). When two or more species live intimately together. Often enhance the survival of one or both.
Mutualism
Species that interact in a way that benefits them both.
Commensalism
An interaction that benefits one species but has little (if any) effect on other species.
Parasitism
This occurs when one species (parasite) deeds on part of another organism (host) usually living in/on the host. Parasite benefits; host doesnāt.
Keystone Species
Plays a critical role in a biological community thatās out of proportion to its abundance.
Primary Productivity
The rate at which primary producers (plants) store energy in the form of organic substances.
Abundance
The total number of organisms in a community.
Diversity
The number of different species, ecological niches, or genetic variation. Often inverse to abundance. Diversity decreases but abundance increases when moving from the equator to poles.
Complexity
of species at each trophic level and the # of trophic levels ina community. A highly interconnected community may have many trophic levels which makes it more complex.
Edge Effects
The boundary between one habitat and its neighbors.
Ecotones
The boundaries between adjacent communities. The transition between two biomes. Influenced by boarding ecosystems. A higher density of organisms and a variety of species.
Climax Community
The community that develops last and lasts the longest.
Primary Succession
Involves the gradual establishment of various biotic communities in lifeless areas where there is no soil in a terrestrial community/no bottom sediment in an aquatic community.
Secondary Succession
A series of communities with different species that develop in places containing soil/bottom sediment.
Pioneer species
Arrive first but may later be replaced by another set of species.
Distrubance-adapted Species
They survive disturbances and donāt allow some landscapes to reach a stable climax.
Saguaro cactus
They can only live in certain temperatures, therefore, have limited distribution. No places that dip below freezing for more than a few hours at a time. Highly Specialized.
