Population Regulation
Population Regulation - Related Videos
14:47
Population Growth - Student Protocol
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2019
Exponential Population Growth Model ExpandNOTE: In these experiments you will use computer software to simulate different types of growth models. HYPOTHESES: The experimental hypothesis might be that if we increase either R, the reproductive rate or the initial population size, NT, that this will increase the population size after 10 generations in an exponential growth model compared to unmanipulated control populations. The null hypothesis may be that populations of different R and initial...
04:45
Population Growth - Concepts
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2019
Population Models An ecological population is a group of individuals of a single species living in an area at the same time. To persist, a population must either grow or maintain its size. Population ecology is the study of how population size and age distribution change over time through interactions with other species and the environment as well as with individuals of their own species. A particularly important feature that is studied by ecologists is the rate at which a population grows or...
02:04
Conservation of Small Populations
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2019
Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less likely to...
01:46
Epigenetic Regulation
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2019
Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer. In most mammals, females have two X chromosomes (XX) while males have an X and a Y chromosome (XY). The X chromosome contains significantly more genes than the Y chromosome. Therefore, to prevent an excess of X chromosome-linked gene expression in females, one of the two X chromosomes is randomly silenced during early development.
02:14
GTPases and their Regulation
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2020
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins. Large G-proteins, also known...
FAQs
Increasing density intensifies competition for food, space, and mates, while disease transmission and predation may also become more important. These pressures can raise mortality or reduce reproduction, slowing further growth. When density declines, the same constraints may weaken, allowing survival or reproductive rates to improve and contributing to population fluctuations over time.
Carrying capacity represents the population level that environmental conditions can support. Competition, limited resources, disease, and predation can push abundance downward when it rises beyond that support level, while reduced pressure may allow recovery after a decline. Comparing observed population changes with carrying capacity helps explain why abundance does not increase indefinitely.
Density-dependent regulation becomes stronger or weaker as population density changes, as seen with competition, disease, and predation. Density-independent events can alter abundance regardless of how crowded a population is; examples include drought, fires, and storms. Distinguishing these influences helps biologists determine whether fluctuations arise mainly from population interactions or external environmental disturbances.
Low density can reduce competition for food, space, and mates, and may lessen some effects of disease or predation. This release from pressure can support increased survival or reproduction, although environmental conditions still constrain the population. Recognizing this contrast between crowded and sparse conditions helps explain changing abundance rather than treating every decline or increase as random.
Biologists can relate where a species occurs to the environmental conditions and interactions that limit abundance. Food, space, mates, disease, predation, drought, fires, and storms can all influence whether local conditions support a population. This perspective helps connect population size with geographic distribution and clarifies why a species may be common in some areas but absent from others.
Conservation planners and wildlife managers can use regulatory factors to anticipate how populations respond to changing conditions. Evaluating competition, disease, predation, resource availability, and environmental disturbances helps identify pressures that may reduce abundance or permit recovery. Such information supports decisions about managing wildlife populations and protecting the environmental conditions they require.
Predictions should account for both density-dependent interactions and density-independent disturbances. A changing environment may alter competition for food, space, or mates while also increasing exposure to drought, fires, or storms. Considering these influences together provides a stronger basis for anticipating shifts in abundance, carrying capacity, fluctuations, and species distribution.