Podcast
Questions and Answers
What is the main difference between a synonymous and a non-synonymous substitution in a protein-coding sequence?
What is the main difference between a synonymous and a non-synonymous substitution in a protein-coding sequence?
- Synonymous substitutions are more likely to be under positive selection than non-synonymous substitutions.
- Synonymous substitutions do not change the amino acid sequence, while non-synonymous substitutions do. (correct)
- Synonymous substitutions are more common than non-synonymous substitutions.
- Synonymous substitutions change the amino acid sequence, while non-synonymous substitutions do not.
According to the neutral theory of molecular evolution, what explains the observation that molecular clocks are approximately linear?
According to the neutral theory of molecular evolution, what explains the observation that molecular clocks are approximately linear?
- The majority of substitutions at the molecular level are neutral and not subject to strong selection. (correct)
- The elimination of old alleles and the substitution of new alleles requires lots of genetic deaths, leading to a linear rate of substitution.
- Positive selection drives the rapid fixation of new alleles, leading to a linear rate of substitution.
- Different proteins evolve at different rates due to varying levels of functional constraint.
How do synonymous substitutions relate to the use of molecular clocks?
How do synonymous substitutions relate to the use of molecular clocks?
- Synonymous substitutions are not useful for molecular clocks because they do not alter the amino acid sequence.
- Synonymous substitutions are too rare to be useful for molecular clocks, which rely on the accumulation of substitutions over time.
- Synonymous substitutions are under strong positive selection and therefore do not provide a reliable molecular clock.
- Synonymous substitutions are the best molecular clock to normalize rates of substitution, as they typically diverge at rates similar to non-functional sequences. (correct)
What is the main difference between measuring selection on protein-coding genes versus measuring selection on synonymous and non-synonymous substitutions?
What is the main difference between measuring selection on protein-coding genes versus measuring selection on synonymous and non-synonymous substitutions?
Which of the following is an example of a 'living fossil' that exhibits slow rates of morphological change?
Which of the following is an example of a 'living fossil' that exhibits slow rates of morphological change?
What is the proposed explanation for the slow rate of morphological change observed in the horseshoe crab, a 'living fossil'?
What is the proposed explanation for the slow rate of morphological change observed in the horseshoe crab, a 'living fossil'?
What is the formula for measuring DNA Evolution by determining the divergence between sequences?
What is the formula for measuring DNA Evolution by determining the divergence between sequences?
Which type of substitution occurs when a nucleotide change does not result in an amino acid change in the protein product?
Which type of substitution occurs when a nucleotide change does not result in an amino acid change in the protein product?
What does a substitution rate measure in terms of DNA evolution?
What does a substitution rate measure in terms of DNA evolution?
How is the rate of neutral evolution calculated?
How is the rate of neutral evolution calculated?
When applying the molecular clock, what does a negative sequence divergence value indicate?
When applying the molecular clock, what does a negative sequence divergence value indicate?
In measuring selection on genes, what does a higher ratio of non-synonymous substitutions to synonymous substitutions imply?
In measuring selection on genes, what does a higher ratio of non-synonymous substitutions to synonymous substitutions imply?
What is the assumption made about nucleotide frequencies at equilibrium?
What is the assumption made about nucleotide frequencies at equilibrium?
Which of the following is NOT an assumption of common nucleotide substitution models?
Which of the following is NOT an assumption of common nucleotide substitution models?
What is the process of gene conversion, as described in the text?
What is the process of gene conversion, as described in the text?
Which of the following statements about molecular clocks is TRUE?
Which of the following statements about molecular clocks is TRUE?
What is the difference between synonymous and non-synonymous substitutions?
What is the difference between synonymous and non-synonymous substitutions?
What factors can influence the rate of evolution in different genes or genomic regions?
What factors can influence the rate of evolution in different genes or genomic regions?
