Gene duplication occurs when chromosome pairs exchange DNA during the process of meiosis. In some cases, when there is an unequal swapping of DNA, chromosomes may receive an extra DNA, which carries the gene, during the exchange.

Hox genes influence the organism’s body development by controlling the size and shape of the fingers, toes, arms, legs, and other body parts. Small changes in these genes during the development can create significant differences in the appearance of such body parts when they become adults. For example, a small change in timing can result in an extra finger, shorter limbs, or stubby legs.

Through the help of molecular clocks, which show the DNA mutation rate, scientists can estimate the amount of time that has passed since the two species shared a common ancestor. This method can show how these two organisms are closely related.

When a gene is duplicated, the original gene may continue to perform its old role, whereas the duplicated copy of the gene may start to mutate and perform a new role. When this new trait manifests in an organism, it may either increase or decrease their fitness level.

The timing is carefully observed because it controls the growth of an embryo. It is important that the growth must start and stop at exact times. If this doesn’t happen at the exact time, it can affect the development of organisms, which would result in huge differences in the final appearance of organisms. In this case, if the timing of the mutation can be determined, its effect can be predicted.

In studying the DNA sequences of the three species of trout, the following questions may help investigate the evolutionary relationship between the species:

1. What is the size and structure of each trout species?
2. What is the feeding behavior of each trout species?
3. What kind of environmental conditions does each species inhabit?
4. What are the similarities and differences between the trout species?
5. To which family does the trout belong?
6. Are there other fish species that exhibit similar characteristics with the trout?
7. What is the DNA sequence of each trout species?
8. What is the rate of mutation of each trout species?