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| 338209099 | population | group of individuals from the same species that live in the same area at the same time | 0 | |
| 338209100 | population ecology | study of how and why the number of individuals in a population changes over time | 1 | |
| 338209101 | mathematical and analytical tools in pop ecology | help predict changes in pop size and design management strategies to save threatened species | 2 | |
| 338209102 | demography | study of factors that determine the size and structure of populations through time | 3 | |
| 338209103 | populations grow due to | birth and immigration | 4 | |
| 338209104 | populations decline due to | deaths and emigration | 5 | |
| 338209105 | to make predictions about the future of a population, biologists must know: | how many individuals of each age are alive, how likely individuals of diff ages are likely to survive, how many offspring are produced by females of diff ages, and how many individuals of diff ages immigrate and emigrate each generation | 6 | |
| 338209106 | population size should increase over time when | population consists primarily of young individuals with a high survival rate and reproductive rate | 7 | |
| 338209107 | population size should decrease over time when | population is mainly old individuals with low reproductive rates and low survival rates | 8 | |
| 338209108 | life table | summarizes the probability that an individual will survive and reproduce in any given time interval over the course of its lifetime | 9 | |
| 338209109 | survivorship | the proportion of offspring produced that survive, on average, to a particular age | 10 | |
| 338209110 | survivorship curve | a plot of the logarithm of the number of survivors versus age | 11 | |
| 338209111 | type I curve | survivorship throughout life is high, and most individuals approach maximum life span of species (humans) | 12 | |
| 338209112 | type II curve | most individuals experience relatively constant survivorship over their lifetimes (Songbirds) | 13 | |
| 338209113 | type III curve | high death rates early in life, with high survivorship after maturity (many plants) | 14 | |
| 338209114 | fecundity | the number of female offspring produced by each female in the population | 15 | |
| 338209115 | age specific fecundity | average number of female offspring produced by a female in a given age class | 16 | |
| 338209116 | age class | a group of individuals of a specific age | 17 | |
| 338209117 | growth rate of a population | calculated by data on survivorship and fecundity | 18 | |
| 338209118 | fitness trade offs | occur because every individual has a restricted amount of time and energy at its disposal (resources are limited) | 19 | |
| 338209119 | fecundity and survival in a female can be allocated... | by maximizing one or the other, or striking a balance between the two | 20 | |
| 338209120 | life history | describes how an organism allocates its resources to growth, reproduction, and activities or structures related to survival (survivorship, age specific fecundity, age at first reproduction, growth rate,...) | 21 | |
| 338209121 | high fecundity | organism will grow quickly, reach sexual maturity at young age, and produce many small eggs or seeds | 22 | |
| 338209122 | high survivorship | grow slowly, invest their energy and time in traits that reduce damage from enemies and increase their own ability to compete for resources | 23 | |
| 338209123 | per capita rate of increase (r) | difference between birthrate and death rate per individual (r = b-d) | 24 | |
| 338209124 | intrinsic rate of increase (rmax) | when birthrates per individual are as high as possible and death rates per individual are as low as possible (usually not likely) | 25 | |
| 338209125 | exponential population growth | occurs when r does not change over time; does not depend on the number of individuals in the population (density independent); CANNOT CONTINUE INDEFINITELY | 26 | |
| 338209126 | when does exponential growth occur? | when few individuals found a new population in a new habitat....OR when a population has been devastated by a natural catastrophe and then begins to recover, starting with a few surviving individuals | 27 | |
| 338209127 | population density | number of individuals per unit area; when it gets very high, populations per capita birthrate should decrease and the per capita death rate increase, meaning r will decline (density dependent) | 28 | |
| 338209128 | carrying capacity (K) | maximum number of individuals in a population that can be supported in a particular habitat over a sustained period of time; K can change depending on conditions | 29 | |
| 338209129 | carrying capacity depends on conditions | food, space, water, soil quality, resting/nesting sites; varies year to year depending on conditions | 30 | |
| 338209130 | density independent factors | usually abiotic, and change birthrates and death rates irrespective of population size (ie, variation in weather) | 31 | |
| 338209131 | density dependent factors | usually biotic, change in intensity as a function of population size (increased predation with increased deer pop size) | 32 | |
| 338209132 | logistic population growth is caused by | density dependent changes in survivorship and fecundity | 33 | |
| 338209133 | K varies in space | some habitats are better than other habitats due to differences in food availability, space, and other density-dependent factors | 34 | |
| 338209134 | K varies with time | as conditions in some years are better than in others | 35 | |
| 338209135 | age structure | proportion of individuals that are at each possible age; has dramatic influence on pop growth over time | 36 | |
| 338209136 | age pyramids | graphs with horizontal bars representing the number of males and females in each age group; uniform in developed countries, bottom heavy in developing countries | 37 | |
| 338209137 | overall population size in developing countries will | increase dramatically, partly because increased survivorship and because of amount of young women will lead to high overall number of births, event though avg fecundity is much less than it was a gen ago | 38 | |
| 338466360 | population cycles | regular fluctuations in size | 39 | |
| 338466361 | metapopulations | a population of populations | 40 | |
| 338466362 | community | interacting species living within a defined area; interact almost constantly, so population is linked to other species that share its habitat | 41 | |
| 338466363 | competition | occurs when individuals use the same resources, resulting in lower fitness for both (-/-) | 42 | |
| 338466364 | consumption | occurs when one organism eats or absorbs nutrients from another, increasing consumer's fitness but decreasing the victim's (+/-) | 43 | |
| 338466365 | mutualism | occurs when two species interact in a way that confers fitness benefits to both (+/+) | 44 | |
| 338466366 | commensalism | occurs when one species benefits but the other species is unaffected (+/0) | 45 | |
| 338466367 | intraspecific competition | occurs between members of the same species; major cause of density-dependent growth | 46 | |
| 338466368 | interspecific competition | occurs when members of different species use the same limiting resources; occurs when the niches of two species overlap | 47 | |
| 338466369 | niche | the range of resources that the species is able to use or the range of conditions it can tolerate | 48 | |
| 338466370 | asymmetric competition | occurs when one species suffers a much greater fitness decline that the other | 49 | |
| 338466371 | symmetric competition | each species experiences a roughly equal decrease in fitness | 50 | |
| 338466372 | fundamental niche | resources used by or conditions tolerated by a certain species in the absence of competitors | 51 | |
| 338466373 | realized niche | resources it uses or conditions it tolerates when competition occurs | 52 | |
| 338466374 | natural selection, with respect to niches, | favors for both species to avoid competition | 53 | |
| 338466375 | herbivory | consumption of plant tissues by herbivores | 54 | |
| 338466376 | parasitism | consumption of small amounts of tissues from another organism (host) by a parasite | 55 | |
| 338466377 | predation | killing and consumption of most or all of another individual (prey) by the predator | 56 | |
| 338466378 | constitutive/standing defense | defenses that are always present; includes avoidance, poison, flocking, & fighting back; can be extremely effective, but expensive in terms of energy/resources used to produce/maintain them | 57 | |
| 338466379 | aposematic coloration | warning signal for potential predators | 58 | |
| 338466380 | mimicry | the close resemblance of one species to another | 59 | |
| 338466381 | batesian mimicry | resemblance of an innocuous prey to a dangerous prey species | 60 | |
| 338466382 | Mullerian mimcry | resemblance of two harmful prey species | 61 | |
| 338466383 | inducible defenses | defense traits produced only in response to the presence of a predator | 62 | |
| 338466384 | top-down controls | predation or disease limits herbivores | 63 | |
| 338466385 | bottom-up controls | plants provide poor nutrition or are well defended against herbivory | 64 | |
| 338466386 | keystone species | a species that has a much greater impact on the surrounding species than its abundance would suggest | 65 | |
| 338466387 | disturbance | any event that removes some individuals (or biomass) from a community | 66 | |
| 338466388 | impact of disturbance is a function of | the type, the frequency, and the severity of the disturbance | 67 | |
| 338466389 | disturbance regime | most communities experience a characteristic type of disturbance, and in most cases, disturbances occur with a predictable frequency and severity; must be maintained @ normal level or will change dramatically | 68 | |
| 338466390 | pioneering species | first organisms to arrive at a newly disturbed site; usually weeds | 69 | |
| 338466391 | early successional communities | dominated by species that are short lived and small in stature, and that disperse their seeds over long distances | 70 | |
| 338466392 | late successional communities | dominated by species that tend to be long-lived, large, & good competitors for resources such as light and nutrients | 71 | |
| 338466393 | species richness | number of species present in a given community (presence or absence) | 72 | |
| 338466394 | species diversity | includes presence or absence, but also incorporates a species relative abundance | 73 | |
| 338466395 | alpha richness | # species in small, homogeneous area | 74 | |
| 338466396 | gamma richness | # of species across larger landscapes | 75 | |
| 338466397 | beta richness | rate of change of species composition across habitats | 76 | |
| 338466398 | role of island size and isolation | species richness should be higher on larger islands rather than smaller islands, and nearshore islands versus remote islands | 77 | |
| 338466399 | immigration rates eventually decline as the number of species on island increases because | individuals that arrive are more likely to represent a species that is present already, and because competition would prevent a new species from becoming established | 78 | |
| 338466400 | extinction rates will rise more slowly on larger islands | because more space and larger populations | 79 | |
| 338466401 | extinction rates should increase as species richness increases | because niche overlap and competition for resources will be more intense | 80 | |
| 338466402 | distance effects | the farther an island is from the mainland, the fewer number of species will be able to colonize it | 81 | |
| 338466403 | latitudal gradient in biodiversity | communities in tropics have more species than communities in temperate or subarctic environments | 82 | |
| 338466404 | energy hypothesis | contends that high temperature increases productivity and the likelihood that organisms can tolerate the physical conditions in a region, thus increasing species diversity | 83 | |
| 338466405 | area and age hypothesis | argues that the tropical regions have had more time and space for speciation than other regions | 84 | |
| 339149594 | intermediate disturbance hypothesis | regions with a moderate type, moderate frequency, and moderate severity of disturbance should have high species richness and diversity | 85 |
