Training to explain things logically and concisely in English

 My original explanation

The range of the QTL for Ca on Pv04 is 33 Mb long. One chromosome is typically about 50 Mb long, so this QTL is taking effectively three-fifths of the whole chromosome. However, when I visualize it, it looks much shorter. That is because the visualization is based on the genetic distances, not physical distance. The QTL that spans 11-44 Mb is only 5 cM long because it is in the middle of the chromosome, where very few crossovers happen. So, that is why the discrepancy between the QTL range based on the physical position of the markers and the visualized range between them based on the genetic distance appear so different. 

Improved version:

The QTL for Ca on Pv04 spans 33 Mb. Because a chromosome in common bean is typically about 50 Mb long, this QTL covers roughly three-fifths of the chromosome. However, it appears much shorter in the visualization because the plot is based on genetic distance rather than physical distance.

Although the QTL extends from 11 to 44 Mb, it spans only 5 cM. This region is located near the middle of the chromosome, where recombination is infrequent. As a result, a large physical interval corresponds to a relatively short genetic distance. This explains the apparent discrepancy between the QTL interval defined by the physical positions of the markers and its visualized length based on genetic distance.

Training for me

Your underlying reasoning is already strong. The main issue is not logic itself, but compressing the logic into a cleaner sequence and choosing more precise scientific phrasing.

The most suitable training for you would focus on four areas.

First, practise explaining one idea in a fixed causal structure:

Observation → explanation → mechanism → conclusion

For your QTL example:

• Observation: The QTL spans 33 Mb but looks short in the figure.

• Explanation: The figure uses genetic distance, not physical distance.

• Mechanism: Recombination is infrequent near the chromosome centre.

• Conclusion: A large physical interval can correspond to a short genetic interval.

This structure suits you because your original explanation contained all four elements, but they were partly repeated and distributed across several sentences.

Second, practise separating the specific case from the general principle. A strong scientific explanation often moves like this:

1. State the specific result.

2. State the general principle.

3. Apply the principle back to the result.

For example:

The QTL spans 33 Mb physically but only 5 cM genetically. Genetic and physical distances are not proportional, particularly in regions with low recombination. Because this interval lies near the chromosome center, its large physical span corresponds to a short genetic distance.

This pattern is especially useful in presentations and discussions because it helps the listener understand not only what happened, but why the same phenomenon may occur elsewhere.

Third, practise replacing conversational expressions with standard scientific verbs and nouns. Your English is understandable, but some phrases are translated too directly from spoken reasoning.

Examples from your draft:

• “is taking three-fifths” → “covers roughly three-fifths”

• “very few crossovers happen” → “recombination is infrequent”

• “looks much shorter” → “appears much shorter”

• “the discrepancy … appear so different” → “this explains the discrepancy”

• “the range of the QTL” → “the QTL interval” or “the QTL spans”

A useful exercise is to build a personal phrase bank organized by function:

• describing extent: “spans,” “covers,” “extends from”

• explaining causes: “because,” “due to,” “as a result of”

• describing relationships: “corresponds to,” “is associated with,” “does not scale proportionally with”

• interpreting figures: “appears,” “is represented as,” “the plot is based on”

• concluding: “This explains why,” “As a result,” “Therefore”

Fourth, practice removing sentences that merely restate the same relationship. Your original version explains the physical–genetic distance discrepancy several times:

it looks much shorter
the visualization is based on genetic distances
it is only 5 cM long
that is why the discrepancy appears different

All are relevant, but the final sentence repeats what the previous sentences have already established. A useful editing test is:

Does this sentence add a new fact, explain a mechanism, or draw a necessary conclusion?

If it does none of these, delete or merge it.

A training routine particularly suited to you would be:

1. Write the explanation naturally without restricting yourself.

2. Label each sentence: observation, evidence, mechanism, interpretation, or conclusion.

3. Remove repeated labels containing the same information.

4. Rewrite the explanation in three sentences.

5. Rewrite it again in one sentence.

6. Explain it aloud without looking at the text.

For your example, the three-sentence version might be:

The Ca QTL on Pv04 spans 33 Mb physically, covering roughly three-fifths of the chromosome, but it appears much shorter in the visualization. This is because the plot represents genetic rather than physical distance, and the 11–44 Mb interval spans only 5 cM. Because recombination is infrequent near the chromosome centre, a large physical interval can correspond to a short genetic distance.

The one-sentence version would be:

Although the Ca QTL covers 33 Mb on Pv04, it appears short in the visualization because low recombination near the chromosome centre compresses this large physical interval into only 5 cM of genetic distance.

Your highest-priority training is therefore not basic English grammar. It is information structuring, scientific phrase selection, and compression. You already identify the relevant facts and causal mechanism correctly; the next step is learning to package them in the order most useful to the listener.