Natural selection does work on preexisting variations in a population. This is how the population was shaped to be the way that they currently are or were.
different ways in which individuals with particular trait may increase are -if that particular trait provides them with some sort of support to undergo the circumstances they are found in, we can also call it natural selection -or due to any genetic drift, that is a natural calamity, also called a chance selection
If someone from outside of your gene pool were to have a child inside of your population, it could possibly affect the gene pool of your population. If someone from Alaska had a child in Mississippi it would affect the gene pool of Mississippi.
Natural selection can lead to extreme traits in a population if those traits provide a significant advantage in survival or reproduction. Genetic drift can also lead to extreme traits if there are random fluctuations in the frequency of alleles in a population. Additionally, sexual selection can drive the evolution of extreme traits if individuals with those traits are preferred as mates.
There is no need for it to occur. Only if the environment changes and less food is found would there be a change. The environment selects the birds that do the best under the new conditions and the others will die.
New traits in a population can arise through mutations in the DNA of an organism. Mutations are changes in the genetic code that can result in new characteristics that may be passed on to offspring. These traits can then be subject to natural selection and other evolutionary mechanisms.
No, natural selection works on that genetic variation presented to it.
no there is no genetic variation for natural selection to act upon
No, there is no genetic variation upon which natural selection can operate.
What population? Perhaps you mean if there were no variation for natural selection to select from.
Natural selection requires variation in traits within a population, heritability of those traits, and differential reproductive success based on those traits. Without these components, natural selection cannot act on a population.
Yes.
Natural selection tends to decrease genetic variation within a population by favoring certain traits that are advantageous for survival and reproduction.
Without variation there is nothing to select from.
Evolution by natural selection actually relies on variation within a population. Without variation, there would be no genetic differences for natural selection to act upon, leading to no evolution. Variation provides the raw material for natural selection to work with, allowing beneficial traits to be favored and passed on to future generations.
Genetic variation in itself does not 'support' natural selection: it is what natural selection acts upon.
Natural selection acts on variation by picking out from a population's gene pool those that are more fit to survive. More variation leads to more natural selection. For example, currently endangered cheetas are found out to have less genetic variation than other animals. As a result, if a disatrouous event occured, there are no genes that could help the cheetas survived. Thus, natural selection prevent the cheetas from reproducing as a population and they become extinct.
Yes, natural selection requires genetic variation to drive the process of evolution. Genetic variation provides the raw material for natural selection to act upon, leading to changes in the traits of a population over time.