Question

You receive a phone call from your scientist friend. She is studying a new species of bacteria and has recently sequenced the genome of all individuals in her population. She started out with a genetically homogenous population but has just discovered a new mutation. She wants you to predict what the fate of the mutation will be in the population (fixed, lost or maintained as a polymorphism). A) If you are a strict neutralist (neutral theory all the way!!), what 2 pieces of information would you want to know about the mutation and population? Why? B) If you are a nearly neutralist, what 2 pieces of information would you want to know about the mutation and population? Why? C) If you a selectionist (take that Kimura!) what 2 pieces of information would you want to know about the mutation and population? Why?

Answer 1

Mutation is a permanent change in the nucleotide sequence of DNA. Mutation may be due to insertion, deletion or substitution of necleotide base pairs. Polymorphism is common in population whereas mutation is rare variant of the normal. For analysis of this change that the fridnd has observed I would ask for two pieces of information:-

1. What is the frequency of newly observed variant in their population?

2. Does the protein product of this changed variant is same amino acid or some other one. This will let us know whether the function of the gene is altered or not. Then we can categorize this variant properly .