Examples of population in the following topics:
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- Population regulation is a density-dependent process, meaning that population growth rates are regulated by the density of a population.
- In population ecology, density-dependent processes occur when population growth rates are regulated by the density of a population.
- Usually, the denser a population is, the greater its mortality rate.
- A dense population that is reduced in a density-independent manner by some environmental factor(s) will be able to recover differently than would a sparse population.
- In this population of roundworms, fecundity (number of eggs) decreases with population density.
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- Population genetics is the study of the distributions and changes of allele frequency in a population.
- Population genetics is the study of how selective forces change a population through changes in allele and genotypic frequencies.
- In population genetics, the term evolution is defined as a change in the frequency of an allele in a population.
- When a small number of individuals become the basis of a new population, this new population can be very different genetically from the original population if the founders are not representative of the original.
- Define a population gene pool and explain how the size of the gene pool can affect the evolutionary success of a population
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- Population size and density are the two most important statistics scientists use to describe and understand populations.
- For example, a larger population may be more stable than a smaller population.
- Analyses of sample data enable scientists to infer population size and population density about the entire population.
- A variety of methods can be used to sample populations.
- Choose the appropriate method to sample a population, given features of the organisms in that population
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- The variation of populations over time, also known as population dynamics, depends on biological and environmental processes that determine population changes.
- With knowledge of this age structure, population growth can be more accurately predicted.
- Some developed countries, such as Italy, have zero population growth.
- The stable population diagram is rounded on top; the older part of the population is a larger proportion of the population than in the other age diagrams.
- Explain how age structure in a population is associated with population growth and economic development
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- The "population growth rate" is the rate at which the number of individuals in a population increases in a given time period as a fraction of the initial population.
- Specifically, population growth rate refers to the change in population over a time period, often expressed as a percentage of the number of individuals in the population at the beginning of that period.
- This does not mean that the population is declining;
rather, it means the population is growing more slowly.
- According to the UN's 2010 revision to its population projections, world population will peak at 10.1 billion in 2100 compared to 7 billion in 2011.
- The human population has grown most sharply in the past 200 years.
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- Demography is the study of population dynamics, using statistical and mathematical tools.
- Understanding the population dynamics of the carp will help biologists develop and implement measures that reduce its population, allowing scientists to model the statistics of carp populations.
- Populations are dynamic entities, consisting of all of the species living within a specific area.
- Demography, the statistical study of population dynamics, uses mathematical tools to investigate how populations respond to changes in their biotic and abiotic environments.
- The term "demographics" is often used in discussions of human populations, but demographic approaches can be applied to all living populations.
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- This population size, which represents the maximum population size that a particular environment can support, is called the carrying capacity, or K.
- Thus, population growth is greatly slowed in large populations by the carrying capacity K.
- This model also allows for negative population growth or a population decline.
- This fluctuation in population size continues to occur as the population oscillates around its carrying capacity.
- When resources are limited, populations exhibit logistic growth.
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- Genetic drift is the shift of alleles within a population due to chance events that cause random samples of the population to reproduce or not.
- Another scenario in which populations might experience a strong influence of genetic drift is if some portion of the population leaves to start a new population in a new location or if a population gets divided by a physical barrier of some kind.
- In these simulations, alleles drift to loss or fixation (frequency of 0.0 or 1.0) only in the smallest population.Effect of population size on genetic drift: Ten simulations each of random change in the frequency distribution of a single hypothetical allele over 50 generations for different sized populations; first population size n=20, second population n=200, and third population n=2000.
- "founders") separates from the old population to start a new population with different allele frequencies.
- Genetic drift in a population can lead to the elimination of an allele from that population by chance.
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- Genetic variation is a measure of the genetic differences that exist within a population.
- Some species display geographic variation as well as variation within a population.
- New genetic variation can be created within generations in a population, so a population with rapid reproduction rates will probably have high genetic variation.
- Populations of wild cheetahs have very low genetic variation.
- Assess the ways in which genetic variance affects the evolution of populations
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- Population size, density, and distribution patterns describe a population at a fixed point in time.
- To study how a population changes over time, scientists must use the tools of demography: the statistical study of population changes over time.
- Biological features of the population also affect population changes over time.
- The demographic characteristics of a population are the basic determinants of how the population changes over time.
- If birth and death rates are equal, the population remains stable.