Suppose that species 1, 2, and 3 are closely related to one another. If you sequence a gene and find 10 nucleotides where these species differ from each other, you can use such data to estimate the distance between them. The nucleotide bases at these sites are

Mutations

Explanation:

Mutations are the main causes of diversity among organisms as they cause changes in the genetic sequence of organisms. Mutations typically refer to changes in nucleic acids. Changes caused by mutation could take different forms. Some mutations are substitutions in a single nucleotide. some are deletions, some insertions. Mutations can also occur in either somatic (body) cells or in germ cells.

When a mutation occurs in the somatic cell, the mutation affects just the single organism carrying the mutation. However, when the mutation is present in germ cells, the mutation can be passed down to offspring. The implication of germ cell mutations is that, the mutation spreads across a population of the species.

Mutations could cause the substitution of amino acid sequences, cause the premature termination of protein synthesis or could even have no obvious effect, depending on the type of mutation that occurs. Some mutations are harmless, while others are harmful. The higher the number of mutations, the higher the chances of the mutation being harmful to the organism.

we would need to see the picture to answer it