What causes spatial and temporal differences in the expression of a single gene?

Then I recalled one aspect of life in which little differences cause big differences.

Confusingly, some of the factors that cause internal differences do not seem to apply on a global level.

It appears that other factors, for which adjustments are not made, do not cause significant differences.

This variance causes differences in how females choose their mates.

This forces researchers to question what causes regional differences in voting outcomes.

This sound can of course occur in other places and cause differences in meaning.

The game uses a day/night system, causing differences in enemies.

The order of adoption may also cause significant differences in their relationship.

From this followed the key discovery of what causes differences in tone color.