The war of the sexes between the beetles-gravediggers leads to some interesting changes.
Biologists from Exeter University revealed that the war of the sexes between the beetles-gravediggers (Nicrophorus) leads to changes in the shape of genitalia in insects. In males they become longer, and females have larger claws on their genitals. A study published in the journal Evolution.
The war of the sexes occurs in the collision of interests of males and females. The first aim is to increase the number of their offspring of breeding with many females, whereas the latter seek to prevent this due to the extra energy costs that can hinder them to educate their offspring. It is shown that such different sexual strategies lead to an arms race, and therefore there are evolutionary changes in the shape of genitals.
To test whether sexual conflict can lead to changes of the genital organs in males and females beetles gravediggers, the researchers conducted an artificial selection among insects for signs of high and low speed pairing for ten generations. Scientists have demonstrated that selection has influenced the shape of the genitals as males and females.
Interestingly, the change from one sex were associated with changes in another. Males increased the size of their penises, while females have in response become more pronounced claws, which help to prevent mating.
According to modern scientific ideas, in most animals, males tend to monogamous behavior, so they have adaptations that allow them to increase the chances of fertilization of one female at a time, more profitable as females mate with multiple males, which contributes to the onset of strong and healthy offspring.
