There is a final twist to this tale: Gardner and Ross think that the scale insects carry a passenger that could have quickened the demise of the males – a bacterium.
Many insects carry helpful bacteria that provide them with important nutrients, and the cottony cushion scale is no different.
And this means that scale insects can be father, mother, grandfather family tree.
Scale insects are small animals that suck on plant sap for a living.
They developed a mathematical model to simulate these sexual conflicts among ancestral scale insects where the sexes were still separate.
The model accounts for the fact that daughters aren’t infected with any old parasitic tissue – it comes from their “father”, and carries many of the same genes that they have.
At some time, there would have been a tipping point when conflict gave way to collaboration.
Females would pass on more of their own genes to the next generation if they mate with their own parasitic fathers rather than with other males.
Their model predicts that when this odd tactic first evolved, the infectious tissue would probably have harmed the females in some way, who would have adapted to suppress it.
Sons are a dead-end; daughters provide vessels that sail into the next generation.
With great protection and an easy retreat, Hermaphrodite Flake is an exceptional introduction to Tuolumne multi-pitch climbing.
Normal males started to disappear and the hermaphrodites took over.
Rather than existing as a distinct sex, males turned into a lineage of parasitic tissue, passed down from one daughter to the next.