Science

What are R and K strategists?

The terms “r-strategy” and “K-strategy” come from population biology mathematics and designate two points on a continuum where gamete production and longevity engage in a compensating exchange (the K-strategy).

What are r strategists and K strategists examples?

Bacteria, insects and corals are few examples of r strategists while human, primates, and elephants are few examples of K strategists. One other notable difference between r strategist and K strategist is their sizes. The r strategist is smaller in size while the K strategist is larger.

What animals are r strategists?

Examples of r-strategist species are dogs, cats, insects, and fish.

What do K strategists do?

K-selected species, also called K-strategist, species whose populations fluctuate at or near the carrying capacity (K) of the environment in which they reside. Such species make up one of the two generalized life-history strategies posited by American ecologist Robert MacArthur and American biologist Edward O.

What is the R strategy in biology?

r-selected species, also called r-strategist, species whose populations are governed by their biotic potential (maximum reproductive capacity, r). Such species make up one of the two generalized life-history strategies posited by American ecologist Robert MacArthur and American biologist Edward O.

What is R vs K selection?

In ecology, r/K selection theory relates to the selection of combinations of traits in an organism that trade off between quantity and quality of offspring.

What are K-selected species?

K-selected species possess relatively stable populations fluctuating near the carrying capacity of the environment. These species are characterized by having only a few offspring but investing high amounts of parental care. Elephants, humans, and bison are all k-selected species.

Are goats K strategist?

Generally, the animals that are found acceptable by society to eat today are essentially K-strategists. These include meat coming from cows, swine, goat, chicken, among others.

Is a human r strategist or K strategist?

Their reproductive strategy is to grow slowly, live close to the carrying capacity of their habitat and produce a few progeny each with a high probability of survival. Typical K-selected organisms are elephants, and humans.

What is the difference between a K and R strategist species quizlet?

Identify differences between K- and r-selected species. K-selected species are typically more adversely affected by invasive species than r-selected species, which are minimally affected by invasive species. Most invasive species are r-selected species.

What is R and K species?

R- and K-selection constrain the range of viable species through the colonization-competition tradeoff, with strong r-selection favoring colonizers and strong K-selection favoring competitors, but the level of disturbance also affects the success of species.

What does K selection mean?

selection occurring when a population is at or near the carrying capacity of the environment, which is usually stable: tends to favor individuals that successfully compete for resources and produce few, slowly developing young, and results in a stable population of long-lived individuals.

What is an R strategist quizlet?

r-strategists. tolerate unpredictable conditions by using a wide variety of resources. k-strategists. thrive in predictable environments but compete for high-quality resources.

Which of the following is an r-selected species?

R-selected species are those that produce many offspring that have a lower probability of surviving to adulthood. Typical examples of these species include mice and rabbits, and all species of Texas quail fall within this classification.

What is K selection quizlet?

K-Selected Species. Population is stable and usually stays close to carrying capacity (K)

Are cats r-selected?

Cats and dogs are r-selected compared to humans, but K-selected compared to mice and rats. Mice and rats, in turn, are K-selected compared to most insects. We can think of an r-K selection continuum and an organism's position along it in a particular environment at a given instant in time (Pianka 1970).

Is a frog an r-selected species?

Other examples of r-selected species include frogs, bacteria, and dandelions.

Are minnows R strategists?

Select from the following list the species that are r -strategists: minnow, giraffe, human, beetle, bacteria, eagle, and cougar.

What is an example of a r-selected species?

Examples of r-selected species are marine invertebrates, such as jellyfish, and plants, such as the dandelion. Dandelions have small seeds that are dispersed long distances by wind; many seeds are produced simultaneously to ensure that at least some of them reach a hospitable environment.

Are sea turtles R or K?

Similarly, reptiles such as sea turtles display both r- and K-traits: although large organisms with long lifespans (should they reach adulthood), they produce large numbers of unnurtured offspring.

Are snakes R or K strategists?

Members of squamate (large lizards and snakes) and Cricetidae (a rodent family) tend to fall more towards the r-selected side of the scale, therefore, the number of offspring plays a large role in the population size. It is also important to note that evolution is what caused species to be r-selected or K-selected.

Which organism best illustrates K selection?

Which organisms best illustrates K-selection? Guppies from Trinidad form two distinct populations that differ in several life history traits. These traits appear to relate to the local predator populations, pike-cichlids or killifish.

Are rabbits r-selected?

R-selected organisms, those emphasizing a fast growth rate, high number of offspring, include rabbits, bacteria, salmon, plants such as weeds and grasses, etc.

Are amphibians R strategists?

While the “typical” amphibian reproduction strategy would fall under the r end of the continuum, those that fall closer to the K end are some of the most remarkable and unbelievable adaptations that the animal kingdom has ever produced.

What is N in population equation?

In this equation, d N / d T dN/dT dN/dTd, N, slash, d, T is the growth rate of the population in a given instant, N is population size, T is time, and r is the per capita rate of increase –that is, how quickly the population grows per individual already in the population.

What is the distinction between factors that regulate population size and factors that determine population size?

Population size is regulated by factors that are dependent or independent of population density. Biological and non-biological factors can influence population size. Biological factors include interspecific interactions like predation, competition, parasitism, and mutualism, as well as disease.

Which of the following is a characteristic of K-selected species?

Large body size and longer life span are characteristic of k-selected species.

What does R mean in apes?

R-Selected Species. weak competitive ability. R-Selected Species. variable population size, often well below carrying capacity. R-Selected Species.

What is exponential and logistic growth?

Exponential growth is a growth in population wherein the number of individuals increases. This happens even when the rate of growth does not change. As a result, it creates an explosion of the population. Logistic growth entails exponential growth in population along with a growth rate which is in a constant state.

What is a Type Two survivorship curve?

A type II survivorship curve shows a roughly constant mortality rate for the species through its entire life. This means that the individual's chance of dying is independent of their age. Type II survivorship curves are plotted as a diagonal line going downward on a graph.

What causes a Type 3 survivorship curve?

Type III or concave curves have the greatest mortality (lowest age-specific survival) early in life, with relatively low rates of death (high probability of survival) for those surviving this bottleneck. This type of curve is characteristic of species that produce a large number of offspring (see r/K selection theory).

What does Type 1 survivorship curve mean?

In survivorship curve. The Type I curve, illustrated by the large mammals, tracks organisms that tend to live long lives (low death rate and high survivorship rate); toward the end of their life expectancies, however, there is a dramatic increase in the death rate.

What animal has a Type 3 survivorship curve?

Trees, marine invertebrates, and most fish have a Type III survivorship curve. In a Type III curve, very few organisms survive their younger years.

What is K in logistic growth?

k = relative growth rate coefficient K = carrying capacity, the amount that when exceeded will result in the population decreasing.

What is the main difference between logistic and exponential growth curve?

The main difference between exponential and logistic growth is that exponential growth occurs when the resources are plentiful whereas logistic growth occurs when the resources are limited. The exponential growth is proportional to the size of the population. It is influenced by the rate of birth and the rate of death.

What is R in population growth?

The net reproductive rate (r) is the percentage growth after accounting for births and deaths. In the example above, the population reproductive rate is 0.5%/yr. Net reproductive rate (r) is calculated as: r = (births-deaths)/population size or to get in percentage terms, just multiply by 100.

Why are r-selected species Type 3?

R selected species have a large amount of offspring per reproductive age. However they have a Type 3 survival curve which means that most of the offspring die off during their early ages and the few live to their old age.

Why are r-selected species invasive?

R-selected species often grow quickly and mature rapidly. Combined with their explosive reproductive potential, their quick growth and maturation allow them to colonize disturbed and early successional habitats remarkably well. This is not to suggest that all r-selected species are invasive.

Which types of species are better able to survive environmental change R or K-selected?

Which types of species are better able to survive environmental change - r- or k-selected? R selected species are better equipped to survive environmental change because their quick population turn over can quickly adapt.

What is the difference between density-dependent and density independent limiting factors?

Density-dependent limiting factors cause a population's per capita growth rate to change—typically, to drop—with increasing population density. One example is competition for limited food among members of a population. Density-independent factors affect per capita growth rate independent of population density.

What is the relationship between biotic potential and environmental resistance?

Biotic potential increases the population of a species while environmental resistance decreases its growth.

What is the difference between density-dependent and density independent factors?

Density-dependent factors have varying impacts according to population size. Different species populations in the same ecosystem will be affected differently. Factors include: food availability, predator density and disease risk. Density-independent factors are not influenced by a species population size.

What is NT n0e RT?

N is population density. t is time (0 at the start, and t some time-period “t” later) r is the intrinsic rate of population increase under prevailing conditions. If you wish to know how quickly a population grows per generation, use G (generation time) as a substitute in.

What are K selected species?

K-selected species possess relatively stable populations fluctuating near the carrying capacity of the environment. These species are characterized by having only a few offspring but investing high amounts of parental care. Elephants, humans, and bison are all k-selected species.

How do K strategists and R strategists differ?

The key difference between r strategist and K strategist is that the r strategist lives in unstable and unpredictable environments while the K strategist lives in more stable environment. Because of this environmental conditions, the r strategists produce many offspring while the K strategists produce few offsprings.

Which of the following is a K strategist?

Species designated as K-strategists thrive through longevity and have a higher survival rate at birth, but produce far fewer offspring. Examples include elephants and whales.

What animals are K strategists?

Organisms whose life history is subject to K-selection are often referred to as K-strategists or K-selected. Organisms with K-selected traits include large organisms such as elephants, humans, and whales, but also smaller long-lived organisms such as Arctic terns, parrots and eagles.

What is AK strategist species?

K-selected species, also called K-strategist, species whose populations fluctuate at or near the carrying capacity (K) of the environment in which they reside. Such species make up one of the two generalized life-history strategies posited by American ecologist Robert MacArthur and American biologist Edward O.

What does K selection mean?

selection occurring when a population is at or near the carrying capacity of the environment, which is usually stable: tends to favor individuals that successfully compete for resources and produce few, slowly developing young, and results in a stable population of long-lived individuals.

What is an example of an R-strategist?

Examples of r-strategist species are dogs, cats, insects, and fish.

Which of the following is generally true of K-strategist species as compared to R-strategist species?

Which of the following is generally true of K-strategist species as compared to r-strategist species? They have longer life spans.

What are examples of r-selected species?

Examples of r-selected species include pest organisms, such as rodents, insects, and weeds.

Is a frog an r-selected species?

Other examples of r-selected species include frogs, bacteria, and dandelions.

Are cows K species?

Humans, elephants, non-human primates, horses, cows, and the like are all K-selected species. These species have few offspring but invest much energy into ensuring that the offspring survive.

Are rabbits r-selected?

R-selected organisms, those emphasizing a fast growth rate, high number of offspring, include rabbits, bacteria, salmon, plants such as weeds and grasses, etc.

Are cats r-selected?

Cats and dogs are r-selected compared to humans, but K-selected compared to mice and rats. Mice and rats, in turn, are K-selected compared to most insects. We can think of an r-K selection continuum and an organism's position along it in a particular environment at a given instant in time (Pianka 1970).

Are humans R or K strategists?

Both across and within species, r and K strategists differ in a suite of correlated characteristics. Humans are the most K of all. K's supposedly have a longer gestation period, a higher birthweight, a more delayed sexual maturation, a lower sex drive, and a longer life.