0
What else can I help you with?
How does environmental pressure affect natural selection?
When nothing happens to exert strong population pressure on that population, natural selection favors the allele frequency already present. When mutations cause new traits, natural selection weeds these traits out because they're not as efficient as the others.
What is a gene pool and how is it affected by natural selection?
A gene pool is the total number of genes of every individual in an interbreeding population. Which is like having every single gene of a population into one big pool (population).
What level does natural selection occur at?
natural selection occurs when animals need it
What effect does natural selection have on the frequency of a recessive lethal allele?
Perhaps not much as the recessive allele is masked in heterozygous condition. Depends on penetration and expresivity of the lethal allele, but any homozygous expression is fatal, so one can expect negative frequency selection; the freqiency is kept low by selection.
Compare and contrast natural selection and evolution?
Natural selection is the most powerful driver of evolution and it is the only mechanism of evolution ( genetic drift and gene flow are two other mechanisms ) that leads to adaptive change. Natural selection is the nonrandom survival and reproductive success of of randomly varying organisms. Evolution is the change in allele frequency over time in a population of organisms.
Why does selection act faster against a harmful dominant allele than a harmful recessive allele?
Selection acts faster against a harmful dominant allele because individuals with the allele will show the harmful trait, making them more likely to be removed from the population. In contrast, harmful recessive alleles are only expressed in homozygous individuals, making it harder for selection to act on them as carriers of the allele may not exhibit the harmful trait.
Why might a harmful allele persist in a population for many generations?
A harmful allele may persist in a population due to genetic drift, where chance events can lead to its continued presence. Additionally, if the allele is recessive or has a late-onset effect, it may not be selectively disadvantageous enough to be eliminated by natural selection. Finally, a harmful allele may also persist if it is linked to a beneficial allele in the genome, creating a genetic trade-off.
Does natural selection on single-gene trait cannot lead to changes in allele frequencies?
Natural selection acting on a single-gene trait can lead to changes in allele frequencies within a population. If individuals with a certain allele have a selective advantage, they are more likely to survive and reproduce, leading to an increase in the frequency of that allele in the population over time. This process is known as directional selection.
How does environmental pressure affect natural selection?
When nothing happens to exert strong population pressure on that population, natural selection favors the allele frequency already present. When mutations cause new traits, natural selection weeds these traits out because they're not as efficient as the others.
What does it mean when an allele reaches fixation in a population?
When an allele reaches fixation in a population, it means that all individuals in the population carry that specific allele, and no other alleles for that gene are present. This can happen through natural selection, genetic drift, or other evolutionary processes.
Which force of evolution makes a population more alike?
Stabilizing selection occurs when the extreme forms of some trait are selected against by natural selection. It is a force of natural selection which causes evolution (definition: change of allele frequency in a population divided by time).
What is a process that eliminated harmful allele from a gene pool?
negative selection.
Will a dominant allele always increase in frequency over time?
No, a dominant allele will not always increase in frequency over time. The frequency of an allele in a population can be influenced by various factors such as natural selection, genetic drift, and gene flow.
What is direct selection?
Directional selection is when natural selection favors a single phenotype. It occurs when there is a shift in population towards an extreme version of a beneficial trait.
What does it mean for a population to be in genetic equilibrium?
A population is in genetic equilibrium when allele frequencies remain constant over generations, indicating that there is no evolution occurring. This suggests that the population is not experiencing any genetic drift, gene flow, mutations, or natural selection.
Which is more likely to be true natural selection or evolution?
Evolution, of course. Evolution can happen without natural selection in some cases; drift, flow. Generally though, natural selection causes evolution and then, by definition, would come first.
What effect does natural selection have on the allele frequency of a population?
In the next generation that trait increases in frequency above the frequency in the current generation.
