Why is the use of a molecular clock controversial?Multiple choice question.It does not incorporate information from the fossil record about the timing of evolutionary events.It assumes that DNA divergence rates are constant over time.It is only useful in some species.It assumes that rates of evolution are different for different genes.
Question
Why is the use of a molecular clock controversial?Multiple choice question.It does not incorporate information from the fossil record about the timing of evolutionary events.It assumes that DNA divergence rates are constant over time.It is only useful in some species.It assumes that rates of evolution are different for different genes.
Solution
The use of a molecular clock is controversial for several reasons:
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It does not incorporate information from the fossil record about the timing of evolutionary events: The molecular clock hypothesis is based on the assumption that changes in DNA sequences occur at a constant rate over time. However, this does not take into account the information from the fossil record, which can provide direct evidence about the timing of evolutionary events.
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It assumes that DNA divergence rates are constant over time: This is a major assumption of the molecular clock hypothesis. However, it is known that mutation rates can vary greatly among different organisms and even among different genes within the same organism. This can lead to inaccuracies in the estimated times of evolutionary events.
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It is only useful in some species: The molecular clock hypothesis is not universally applicable. It works best for closely related species and is less accurate for distantly related species or those with unusual life histories or population structures.
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It assumes that rates of evolution are different for different genes: This is another major assumption of the molecular clock hypothesis. However, it is known that different genes can evolve at different rates, depending on factors such as their function, the selective pressures acting on them, and their level of expression.
Therefore, while the molecular clock is a useful tool in evolutionary biology, its limitations and assumptions make it a subject of ongoing debate and research.
Similar Questions
What is the main assumption behind the idea of a molecular clock?Multiple choice question.A constant rate of evolution of a moleculeA constant radioactivity rate in fossilsThe presence of a stable molecule that does not change over timeA constant rate of breakdown of an unstable molecule over time
Select all that applySelect all of the following that are true about molecular clocks.Multiple select question.They use the mutation rate of genes to determine the time of divergence from a common ancestor.They can be used to predict when new species are going to form in the future.They can be used to estimate when humans and chimps diverged from a common ancestor.They can be used in absolute dating of fossils.
Why is mtDNA referred to as a molecular clock?2018 Atomi QuestionA(Choice A)It replicates in synchrony with the cell cycleB(Choice B)We use it to estimate the age of individualsC(Choice C)Alterations in mtDNA occur irregularlyD(Choice D)We use it to estimate the date that different species diverged
A(n) clock uses differences in DNA to determine when organisms diverged from a common ancestor.
When using a molecular clock, the rate of DNA divergence between two clades per unit time can be determined by dividing Blank______.Multiple choice question.the length of time separating the clades by the total amount of DNA divergence between the two cladesthe number of bases in a DNA molecule by the length of time separating the cladesthe total amount of DNA divergence between the two clades by the length of time separating the clades
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