lectures 15 pop ecology

The current estimated global population is more than 6.6 billion people and it is increasing by about 75 million each year.

The third hypothesis is about the correlation between sunspot activity and hare populations. The researchers found a weak correlation between the two, but it is not clear how sunspot activity could affect hare populations.

<p>The third hypothesis is about the correlation between sunspot activity and hare populations. It is weakly supported.</p> Signup and view all the answers

<p>The study of groups of individuals of the same species in the same area</p> Signup and view all the answers

<p>Food availability</p> Signup and view all the answers

<p>Population ecology is the study of populations in relation to their environment.</p> Signup and view all the answers

<p>The study of populations in relation to their environment</p> Signup and view all the answers

<p>To explain how a population grows slowly as it nears its carrying capacity</p> Signup and view all the answers

<p>Population ecology studies the group of individuals of the same species in the same area, their resource needs, and how they interact and breed. Population size, density, distribution, and biomass are important parameters to estimate population abundance.</p> Signup and view all the answers

<p>The logistic model describes how a population grows slowly as it nears its carrying capacity. It takes into account the environmental limitations that prevent a population from indefinitely increasing in size.</p> Signup and view all the answers

<p>Size, density, distribution, and biomass</p> Signup and view all the answers

<p>7.8-10.8 billion people</p> Signup and view all the answers

<p>Mark-recapture is a common method to estimate population size, where a sample is marked and released, and then recaptured to estimate the total population size.</p> Signup and view all the answers

<p>Population ecologists predict a population of 7.8-10.8 billion people on Earth by 2050.</p> Signup and view all the answers

<p>The three fundamental characteristics of individuals in any population are density, dispersion, and demographics.</p> Signup and view all the answers

<p>The cyclic population changes of lynx and snowshoe hares are likely due to a combination of food availability and predator-prey interactions.</p> Signup and view all the answers

<p>Birth and death; immigration and emigration</p> Signup and view all the answers

<p>The cyclic population changes of lynx and snowshoe hares are likely due to a combination of food availability and predator-prey interactions.</p> Signup and view all the answers

<p>Density, dispersion, and demographics</p> Signup and view all the answers

<p>Weak correlation</p> Signup and view all the answers

<p>Life history traits are products of natural selection, which shapes the timing and amount of reproduction and survival strategies of organisms. These traits play a crucial role in determining an organism's fitness and success in its environment.</p> Signup and view all the answers

<p>Uniform dispersion</p> Signup and view all the answers

<p>Sampling</p> Signup and view all the answers

<p>The three types of population distribution are clumped, uniform, or random, and they affect the availability of resources and interactions among individuals.</p> Signup and view all the answers

<p>The three patterns of dispersion are uniform, random, and clumped. An example of uniform dispersion is humans living in a city with evenly spaced buildings and housing. An example of random dispersion is plants with wind-dispersed seeds randomly scattered by the wind. An example of clumped dispersion is elephants gathering around a watering hole in groups.</p> Signup and view all the answers

<p>Countries of the former Soviet Union and sub-Saharan Africa</p> Signup and view all the answers

<p>Global life expectancy has been increasing since about 1950, but more recently it has dropped in a number of regions.</p> Signup and view all the answers

<p>The study of the vital statistics of populations and how they change over time</p> Signup and view all the answers

<p>Ecologists use a variety of sampling techniques to estimate densities and total population sizes.</p> Signup and view all the answers

<p>Sunspot activity affects the population cycles of hares</p> Signup and view all the answers

<p>When hare numbers are high, predators such as lynx have more food available and their population grows. As predator numbers increase, hare numbers decline, leading to a decrease in predator numbers, and the cycle begins again.</p> Signup and view all the answers

<p>When hare numbers are high, predators such as lynx have more food available and their population grows. As predator numbers increase, hare numbers decline, leading to a decrease in predator numbers, and the cycle begins again.</p> Signup and view all the answers

<p>They turn on one another, accelerating their own collapse</p> Signup and view all the answers

<p>Countries of the former Soviet Union and sub-Saharan Africa.</p> Signup and view all the answers

<p>Clumped, uniform, and random</p> Signup and view all the answers

<p>Ecologists tested the hypothesis that sunspot activity affects the population cycles of hares. They found that periods of low sunspot activity were followed by peaks in the hare population, suggesting that both predation and sunspot activity regulate hare numbers.</p> Signup and view all the answers

<p>Vital statistics of a population, such as survival rates and reproduction rates, depend on the population structure and its life history traits.</p> Signup and view all the answers

<p>Ecologists tested the hypothesis that sunspot activity affects the population cycles of hares. They conducted experiments during low sunspot activity to observe the effect on hare populations.</p> Signup and view all the answers

<p>The process by which individuals with advantageous traits are more likely to survive and reproduce</p> Signup and view all the answers

<p>Demography is the study of the vital statistics of populations and how they change over time.</p> Signup and view all the answers

<p>Certain metals and fossil fuels</p> Signup and view all the answers

<p>Natural selection favors traits that improve an organism’s chances of survival and reproductive success, which make up its life history.</p> Signup and view all the answers

<p>They increase</p> Signup and view all the answers

<p>200,000 people</p> Signup and view all the answers

<p>The population's structure and life history traits</p> Signup and view all the answers

<p>The difference between the per capita birth rate and the per capita death rate</p> Signup and view all the answers

<p>The availability of prey is the major factor influencing population changes for predators such as lynx, great-horned owls, and weasels, which depend heavily on a single prey species.</p> Signup and view all the answers

<p>Nonrenewable resources are resources such as certain metals and fossil fuels that cannot be replaced once they are used up. The concern is that humans could run out of these resources.</p> Signup and view all the answers

<p>Exponential growth occurs when a population grows at a constant rate without any limiting factors.</p> Signup and view all the answers

<p>During low sunspot activity, more ultraviolet radiation reaches Earth's surface, causing plants to produce more chemicals that act as sunscreens and fewer chemicals that deter herbivores, thus increasing the quality of the hares' food.</p> Signup and view all the answers

<p>A model that describes how a population grows more slowly as it nears its carrying capacity</p> Signup and view all the answers

<p>Water is a renewable resource that has already exceeded the demands of many populations at the local and even regional level.</p> Signup and view all the answers

<p>Logistic growth occurs when the population growth rate slows down due to limiting factors, while exponential growth occurs when a population grows at a constant rate without any limiting factors.</p> Signup and view all the answers

<p>The exponential model describes population growth in an idealized, unlimited environment.</p> Signup and view all the answers

<p>Both predation and sunspot activity regulate hare numbers, with food availability playing a less important role.</p> Signup and view all the answers

<p>Lynx, great-horned owls, and weasels</p> Signup and view all the answers

<p>When a population grows at a constant rate without any limiting factors</p> Signup and view all the answers

<p>When prey become scarce, predators often turn on one another, accelerating the collapse of the predator populations.</p> Signup and view all the answers

<p>Water</p> Signup and view all the answers

<p>The availability of prey is the major factor influencing population changes for predators such as lynx, great-horned owls, and weasels, which depend heavily on a single prey species.</p> Signup and view all the answers

<p>Population ecology is important to understand the dynamics and management of populations, and to prevent extinction or overexploitation of species.</p> Signup and view all the answers

<p>The maximum number of individuals that a population can support</p> Signup and view all the answers

<p>The maximum stable population size that a particular environment can support</p> Signup and view all the answers

<p>Exponential growth is when a population grows at an increasing rate over time. Rapid growth is when a population is increasing quickly, but not necessarily at an increasing rate.</p> Signup and view all the answers

<p>1950</p> Signup and view all the answers

<p>Food availability plays a less important role in the regulation of hare numbers compared to predation and sunspot activity.</p> Signup and view all the answers

<p>The per capita rate of increase, or r, which equals b - d, indicates whether a population is growing or declining.</p> Signup and view all the answers

<p>Minor role</p> Signup and view all the answers

<p>10.8 billion people</p> Signup and view all the answers

<p>Predator-prey interactions</p> Signup and view all the answers

<p>Population ecology is the study of how populations interact with their environment. It relates to the study of human population growth because it helps us understand how human populations are impacting the environment and how the environment is impacting human populations.</p> Signup and view all the answers

<p>A model that describes population growth in an idealized, unlimited environment</p> Signup and view all the answers

<p>Long-term experimental studies continue to help unravel the complex causes of population cycles.</p> Signup and view all the answers

<p>Carrying capacity (K) is the maximum number of individuals that a habitat can support sustainably. It affects population growth by limiting the availability of resources and eventually slowing down population growth.</p> Signup and view all the answers

<p>When prey become scarce, predators often turn on one another, accelerating the collapse of the predator populations.</p> Signup and view all the answers

<p>The amount of land required to sustain a population's resource consumption</p> Signup and view all the answers

<p>Carrying capacity defines the maximum stable population size that a particular environment can support.</p> Signup and view all the answers