What Does stabilizing selection result in?
Stabilizing selection results in a decrease of a population ‘s genetic variance when natural selection favors an average phenotype and selects against extreme variations. In directional selection, a population’s genetic variance shifts toward a new phenotype when exposed to environmental changes.
How do selective pressures influence the evolution of a species?
Selection pressure means factors that contribute to selection which variations will provide the individual with an increase chance of surviving over others. Because of selective pressures, organisms with certain phenotypes have an advantage when it comes to survival and reproduction. Over time, this leads to evolution.
What is stabilizing selection pressure?
When selective pressures select against the two extremes of a trait, the population experiences stabilizing selection. For example, plant height might be acted on by stabilizing selection. A plant that is too short may not be able to compete with other plants for sunlight.
How do selection pressures affect allele frequencies?
When a phenotype produced by certain alleles helps organisms survive and reproduce better than their peers, natural selection can increase the frequency of the helpful alleles from one generation to the next – that is, it can cause microevolution.
What’s an example of stabilizing selection?
Stabilizing selection in evolution is a type of natural selection that favors the average individuals in a population. Classic examples of traits that resulted from stabilizing selection include human birth weight, number of offspring, camouflage coat color, and cactus spine density.
What is the difference between balancing and stabilizing selection?
The key difference between stabilizing and balancing selection is that stabilizing selection is a type of natural selection which favours average phenotypes in a population while balancing selection is the maintenance of multiple alleles of a gene within a population in order to enhance genetic diversity.
What are the five types of selective pressures?
There are several ways selection can affect population variation: stabilizing selection, directional selection, diversifying selection, frequency-dependent selection, and sexual selection.
What are four different selective agents?
Resource availability – Presence of sufficient food, habitat (shelter / territory) and mates. Environmental conditions – Temperature, weather conditions or geographical access. Biological factors – Predators and pathogens (diseases)
What are some examples of selection pressures?
Predation, competition and disease are examples of selection pressures.
What is stabilizing selection give an example?
The result of stabilizing is the over-representation in a specific trait. For example, the coats of a species of mice in a forest will all be the best color to act as camouflage in their environment. Other examples include human birth weight, the number of eggs a bird lays, and the density of cactus spines.
Does stabilizing selection change the mean?
Stabilizing selection reduces the amount of variation in a trait. For example, very small and very large babies are most likely to die, leaving a narrower distribution of birthweights. Disruptive selection increases the amount of variation in a trait.
What is a stabilizing trend?
Stabilizing selection is the opposite of disruptive selection. Instead of favoring individuals with extreme phenotypes, it favors the intermediate variants. This means that most common phenotype in the population is selected for and continues to dominate in future generations.
What happens when selective pressure is applied to a population?
Selective Pressure Leads to Evolution. Gradually, the population changes, and genes that improve survival and reproduction will become more common, while genes that are disadvantageous to survival and reproduction will become more rare. This change in the genetic makeup of a population is called evolution.
Which is an example of the process of stabilizing selection?
Stabilizing Selection. This process selects against the extreme phenotypes and instead favors the majority of the population that is well adapted to the environment. Stabilizing selection is often shown on a graph as a modified bell curve that is narrower and taller than the norm. Diversity in a population is decreased due to stabilizing selection.
What does the selective pressure of cold weather mean?
The selective pressure of cold weather means that animals that don’t have these characteristics are less likely to survive and reproduce.
Why does stabilizing selection favor the middle of the road?
Over time, some of the genes that control the characteristic can be turned off or masked by other genes, depending on where the favorable adaptations are coded. Since stabilizing selection favors the middle of the road, a blend of the genes is often what is seen.