| A | B |
|---|
| biotic | Living component of environment |
| abiotic | Non-living component of environment such as rainfall, sunlight, temperatures |
| Ecology | The systematic study of how organisms interact with one another and with their environment |
| Population | Group of individuals of the same species occupying a common geographical area (only includes biotic factors) |
| Community | Two or more populations of different species occupying the same geographical area. (only includes biotic factors). Not static, they gradually change over time because the environment changes and species themselves tend to also change their habitats |
| Ecosystem | a community of organisms interacting within a particular physical environment includes the abiotic factors, e.g. soil, rain temperatures, ect. virtually all energy on earth comes from the sun, via photoautotrophs (primarily plants), and it is ultimately distributed throughout |
| autotroph | Auto means self self-feeding organism |
| Troph | feed |
| Producer | organism that uses solar energy (green plants) or chemical energy (some bacteria) to manufacture the organic compounds it needs as nutrients from simple inorganic compounds obtained from its environment. |
| biosphere | The portion of the earth that contains living species. It includes the atmosphere, oceans, soils and the physical and biological cycles that affect them. |
| Population ecology | The study of how populations interact with their environment. |
| population | Group of individuals of the same species occupying a common geographical area |
| habitat | The physical place where an organism lives, e.g. a pine forest or fresh water lake (some organisms such as migratory birds have more than one habitat.) |
| Population size | Number of individuals making up its gene pool |
| niche | The functional role of an organism in a community, its job or position |
| Population density | Number of individuals per unit are of volume |
| Population distribution | The general pattern in which the population members are dispersed through its habitat |
| Clumped | This distribution of individuals are more likely to be found together from this distribution of resources and neutral or positive interactions among individuals |
| Uniform (regular=even) | Individuals are uniformly spaced. Results from (combination of even distribution of resources and negative (antagonistic interactions among individuals) |
| random | Individuals equally likely to be found anywhere (locations of the individuals independent of locations of others. Contributing factors random resource distribution and neutral interactions among individuals. |
| K-selected | this type of individual has a long life span, reproduce slowly, have few young, parental care Example: kangaroos, humans, elephants |
| r-selected | short life span, reproduce quickly,have many young,little parental care, Ex: rodents cockroaches, weeds, sea turtles |
| Population change (r) | Population change (r) = (birth - deaths) + (immigrants - emigrants) |
| Biotic Potential | maximum rate at which a population could grow given optimal conditions (food, water, space) |
| What are the factors that influence biotic potential | age of reproduction,frequency of reproduction,number of offspring produced,reproductive life span,average death rate under ideal conditions |
| Late Loss (Type I) | "example people |
| Constant loss (Type II) | death is often unrelated to age |
| Early loss (Type III) | "death happens frequently when young because on parental care (i.e. sea turtle hatch by themselves)" |
| J-shaped curve | exponential growth of a population, Lag Phase then Exponential Growth, This population has not yet reached its carrying capacity,Requires unlimited resources |
| S-shaped curve | population becomes limited by environmental factors |
| Lag Phase | exp growth phase, Deceleration, Stable Equilibrium Phase |
| Carrying Capacity | the maximum size of a population that an area can support |
| Zero Population Growth (ZPG) | no net increase or decrease in population |
| biotic potential | where conditions are ideal, every member has food, shelter, no predators or pathogens in the environment, maximum reproduction. |
| Limiting factors for biotic potential | water, minerals, predators, shelter, buildup of waste materials usually prevent organisms from reaching their biotic potential |
| Density-independent factors that limit carrying capacity | Natural or man-made disasters |
| Density- dependent factors - limit carrying capacity | Overcrowding can cause diseases, pathogens, and parasites (the three P's plague pathogens, and parasites.) |
| Neutral | Two species that don't interact at all |
| commensalism | Beneficial to one species but neutral to another e.g. birds that nest in trees, epiphytes (plants that grow on other plants) such as tropical orchids. |
| mutualism | An interaction that is beneficial to both species, e.g. plants and their pollinators, plants and animals that disperse their seeds, certain fungi and plant roots. |
| parasitism | An interaction that benefits one species and is detrimental to another. Note that the host is generally not killed. |
| competition | Two or more individual organisms of a single species or two or more individuals of different species attempting to use the same scare resources in the same ecosystem |
| intraspecific competition | Two or more individual organisms of a single species attempting to use the same scare resources in the same ecosystem |
| Interspecific competition | Two or more individual organisms of two or more individuals of different species attempting to use the same scare resources in the same ecosystem |
| Competitive exclusion | Maintains that species who utilize the same resources cannot coexist indefinitely- (one niche, one species) concept. |
| Resource partitioning | minimizing competition with the other for food by spending at least half its feeding time in a distinct portion |
| Pre-productive | 0-14 years of age |
| Productive (reproductive) | 15-44 years of age |
| Post-productive | 45-85+ years of age |
| Population pyramid | Defines relative portions of individuals of each age |
| How Populations Evolve | 1. Populations change over time as a result of environmental pressure (evolution) 2. Allele frequencies in population change if evolutionary forces act upon them (Hardy Weinberg Principle) 3. Mutation is the source of variation |
| Gene Flow | the movement of individuals to and from a population, migration |
| Non random mating | individuals mate with other individuals of their choosing, choice depends on individual and species |
| Genetic Drift | occurs in isolated populations, they become more alike (cheetahs) |
| Directional Selection | evolution favors an extreme trait, more and more individuals have the trait. Rats get longer and longer tails |
| Stabilizing selection | extremes are selected against, favors the average |
| Ways To Estimate Populations | Random Sample and Mark & Recapture |
