deck_4243923 Flashcards
species
a population or group of populations of organisms were member share certain characteristics and can breed freely with one another and produce fertile offspring. different biologists may have different approaches to diagnosing a species boundaries
population
a group of organisms of the same species that live in the same area. species are often composed of many species
natural selection
the process by which traits that enhance survival and reproduction are passed on more frequently to future generations of organisms than traits that do not, thus altering the genetic population through time
mutation
an accidental change in DNA that may range in magnitude from the deletion, substitution, or addition of a single nucleotide, to a change effecting entire sets of chromosomes. mutations provide the new material for evolutionary change
adaptation (evolution)
the process by which traits that lead to increased reproduction success in a given environment evolve in a population through natural selection
adaptation (climate change)
the pursuit of strategies to protect ourselves from the impacts of climate change
adaptive trait
a trait that confers greater likelihood that an individual will reproduce. also called an adaptation
convergent evolution
the evolutionary process by which unrelated species acquire similar characteristics/traits as they adapt to selective pressure from their similar enviroments
speciation
a process by which new species are generated
biodiversity (biological diversity)
the variety of life across all levels of biological organization, including the diversity of species, their genes, their populations, and their communities
artificial selection
natural selection conducted under human direction
phylogenetic tree
a tree like diagram that represents the history of divergence of species or other taxonomic groups of organisms
extinction
the disappearance of an entire species from earth
fossil records
the cumulated body of fossils worldwide, which paleontologists study to infer the history if past life on earth
endemic
native or restricted to a certain region. an endemic species occur only in one place in the world
mass extinction events
the extinction of a large percentage of the worlds species in a very short period of time, earth has been in 5 mass extinction events in the past half-billion years
survivorship curve
a graph that shows the likely-hood of death for members of a population varies with age
demographer
a social scientist who studies population size, density, distribution, age structure, sex ratio, and birth, death, immigration, and emigration rates within the human population
immigration
the arrial of individuals from outside the population
emigration
the departure of individuals from a population
rate of natural increase
the rate of change in a population size resulting from birth and death rates alone
population growth rate
the rate of change in a population size per unit time. counts death, birth, immigration, and emigration rates (is usually measured in time per year)
limiting factor
a physical, chemical, or biological characteristic of the environment that restricts the population growth
carrying capacity
the maximum population size that a given environment can substain
logistic growth curve
a plot that shows the initial exponential growth of a population is slowed and finally brought to a stand still by limiting factors
K-selected
term denoting a species with low biotic potential whose members produce a small number of offspring and take a long time to gestate and raise each of their young, but they invest heavily on the survival and growth of their few offspring
density-independent factors
a limiting factor whose effects are the same no matter the population size
density-dependent factors
a limiting factor whose effects on a population increase or decrease depending on the population density
age structure (age distribution)
the relative number of organisms of each age within a population. age distribution can have a great effect on rates of population growth or decline and are often expressed as a ratio of age classes, consisting of organisms (1) not yet mature enough to reproduce (2) capable of reproduction (3) beyond reproduction years
sex ratio
the proportion of males to females in population
population size
the number of individual organisms present at a given time in an organisms population
specialist
a species that can survive only in a narrow range of habitats that contain very specific recources
generalist
a species that can survive in a wide variety of habitats or use a wide array of recources
niche
the functional role of a species in a community
habitat selection
the process by which organisms select habitats from among the range of optionsencountered
habitat
the specific environment in which an organism lives, including both biotic and abiotic factors
ecology
the science that deals with distribution and abundance of organisms, the interactions between them and their abiotic environment
biosphere
the sum total of all the planets organisms and the abiotic environment with which they inetact
population ecology
the study of the quantitative dynamics of population change and the functions that affect the distribution and abundance of members of a population
community
an assemblage of populations of organisms that live in the same place at the same time
community ecology
the scientific study of the patterns of species diversity and interactions among species, from one to one interactions to complex inter-relationships involving entire communities
ecotourism
visitation of natural area fro tourism and recreation. most often involves tourism by more affluent people, which may offer economic benefits for less affluent communities near natural areas and thus provide economic incentives for conservation of natural areas
phytoplankton
microscopic photosynthetic algae, pratists, and cyanobacteria that drift near the surface of water bodies and generally form the first trophic level in an aquatic food chain.
zooplankton
tiny aquatic animals that feed on phytoplankton and generally make up the second layer of the food chain
competition
a relationship in which multiple organisms seek the same limited recourse
intraspecific competition
competition that takes place among members of the same species
interspecific competition
competition that takes place among members of two or more different species
fundamental niche
the full niche of a species
realized niche
the portion of the fundamental niche that is fully realized (used) by a species
species coexistence
an outcome of intraspecific competition in which no competing species fully excludes the other and the species continue to coexist
competition exclusion
an outcome of interspecific competition competition in which one species excludes another species from a resource entirely
character displacement
a phenomenon resulting from competition among species in which competing species evolve characteristics that better adapt them to specifically use the portion of the resource that they use. the species essentially become more different from each other reducing their competition
resource partitioning
the process by which species adapt to competition by evolving to use slightly different resources, or to use their shared resources in different ways, thus minimizing competition with one another
predation
the process in which one species (the predator) hunts, tracks, captures, and eventually kills its prey
predator
an organism that hunts, capture, kills and consumes individuals of another species, the prey
prey
an organism that is killed and consumed by another species
paratism
a relationship in which one organism, the parasite, depends on another, the host, for nourishment or some other benefit while simultaneously doing the host harm
parasite
the organism in a parasitic relation ship that extracts nourishment or some other benefit from the host
host
the organism in a parasitic relationship that suffers harm while providing the parasite nourishment or some other benefit
parasitoid
an insect that parasitizes other insects, generally causing eventual death of the host