[human20190310]

If I recall correctly, one theory is that octopuses are such voracious cannibals that a swift demise after reproduction evolved to keep them from eating the next generation.

[orange8]

Did that evolution happen faster than it took the previous un-evolved octopuses to eat all their young?

[rangibaby]

I guess so, because if the cannibals had won there would be no octopuses

[rusticpenn]

The cannibal octopi groups would have died out while the suicidal ones lived.