Gravediggers, burying beetle vespilloides.
For males, it is positive to mate often because it increases the number of offspring, while females only have to mate a few times to all the eggs will be fertilized.
It was found that changes of one sex genitalia influenced the development of the second sex organs.
The change was greatest in the group in which mating occurred frequently and sexual conflict was the greatest.
There were males and females genitalia longer responded by developing more marked tags on their genitals, according to the study published in the journal Evolution.
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