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Variation exists within the genes of every population or species as the result of what?
Wiki User
∙ 9y ago
Variation exists within the genes of every population or species as the result of natural selection. The other reason is due to neutrality of mutations.
Wiki User
∙ 9y ago
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What results in the most diverse offspring?
Sexual reproduction leads to variety in offspring.
Natural selection acts on variation by?
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.
What must exist in a population before natural selection can act?
Competition + Variation. Classic example: Giraffes not always had long necks. There were variation in the species. When food sauces grew low competition increases and those with longer necks survived (more fruit/food at the top of trees) as they were more suited to the conditions. These long necked giraffes then breed and the offspring have long necks, thus natural selection of a "fitter" species. Hense - survival of the fittest.
What is the smallest level on which evolution can occur?
Natural selection acts upon the individual organism, whilst evolution occurs at the population level. The environment selects for organisms best adapted for highest survival and reproductive success. Natural selection requires three key things - variation, inheritable traits, and differential survival/reproduction. Species will produce more offspring than the environment can support(carrying capacity), and the population tends to be fairly stable until resources are limited. A struggle for existence is created, and natural selection ensures that weaker traits die out while stronger traits live on. Organisms show variation in characteristics, and that variation is heritable. Survival depends on inherited traits, and unequal survival/reproduction leads to adaptation and evolution. Therefore, while the individual organism can adapt, the population is what actually evolves.
When are two populations considered new and separate species?
A new species can occur when;1. Change in allele frequencies-genetic drift can result in loss of alleles in a population-one allele becomes the only variation, becomes "fixed"2. Gene flow due to migration-movement of alleles into or out of a population3. Non-random mating-individuals have preferred mates rather than random4. Mutations-a change in DNA can be beneficial, neutral, or harmful5. Natural Selection-best adapted, more likely to survive
What is a result of the limited genetic variation in the current cheetah population compared to earlier cheetah populations with more variation?
d. current populations of cheetahs are able to interbreed with other species, increasing genetic variation.
What may a series of helpful variation in a species result in?
Adaptation
Is adaptations a genetic basis for variation within a species?
No, adaptations usually do not result in any genotypical change in a species.
How is variation generated in species?
Variation is encouraged when a species has a large population and there is pressure for individuals to modify their nesting, hunting, eating, sleeping, mating and even preferred locality behaviors to compensate for what will otherwise result in death. The more extreme the pressure to "change" normal behavior the more likely the changes will allow abberant alleles to come to the fore, and eventually result in speciation.
Why does sexual reproduction result in genetic variation in a species?
It mixes the chromosomes of the two parents
Explain how a species can reproduce asexually How does this impact genetic variation?
the cell goes through mitosis (interphase, metaphase, anaphase, telophase) and it splits into two identical cells (during this process the DNA is duplicated). As a result of asexual reproduction, there is no variation in population.
Why does sexual reproduction result in more in genetic variation in a species?
It mixes the chromosomes of the two parents
Why does sexual production result in more genetic variation in a species?
It mixes the chromosomes of the two parents
Why genetic variation is of to benefit to a population?
It can provide resistance to diseases or other beneficial characteristics. -variation in more competitive species than our own can result in natural selection that is better focused to the specific environment: there is a bigger range of characteristics, so the best traits allow those members to survive longer and therefore mate more. This allows the species overall to constantly reproduce the beneficial traits and flourish.
Why variation is important?
Variation is important because it produces species with different gene combinations which result in the new offspring to become more immune to other dieseases.
What is a result of the limited genetic variation in the current cheetah populations compared to earlier cheetah populations with more variation?
d. current populations of cheetahs are able to interbreed with other species, increasing genetic variation.
What causes many endangered species that now found only in zoos to have very little genetic variation?
Founder effect refers to the loss of genetic variation when a new colony is established by a very small number of individuals from a larger population. As a result of the loss of genetic variation, the new population may be distinctively different.Bottleneck effect is an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing, and the population is reduced by 50% or more, often by several orders of magnitude.Population bottlenecks increase genetic drift, as the rate of drift is inversely proportional to the population size.They also increase inbreeding due to the reduced pool of possible mates.
