A culture that include the concept of a “raiser”—an octopus with the job of raising the babies, and passing the culture on to them, without mating at all—can avoid that issue. The “raiser” would also improve his average genetic fitness if he is a sibling of one of the parents, since the children would then all have approximately one-quarter of his genes.
This is a lot less motivation than for parents.
If it’s not enough to kill off the species, evolution generally won’t drop the feature.
Well, for starter if you don’t die after mating you might be able to mate again.
According to my source, which is a blog comment that doesn’t site its sources, the death is a form of controlled cell-death and scientists have been able to remove the gene responsible and the resulting octopuses (or squid) can mate again later.
Well, for starter if you don’t die after mating you might be able to mate again.
This might—purely hypothetically—lead to a massive boom in octopus population, causing the octopi to eat everything edible, causing mass starvation.
Or it might be that octopi lack any form of parental instinct; that, six months after the babies are born, the parents see them as “food”, severely reducing the probability of there being another generation. (This would even be an advantageous mutation for octopi that die after mating, because it means that a given genetic line will work towards eradicating the children of any other genetic lines, giving their children less competition...)
Either way, until an octopus in the wild develops the “does-not-die-after-mating” mutation on its own (or possibly escapes from the lab, if what those scientists did is inheritable), evolution will do nothing to get rid of it. And once it does turn up in the wild—well, all else being equal, I’d expect that mutation would supplant the previous, “die-after-mating” model eventually… after a few thousand years or so. Evolution is not, by any means, a completed process.
I’m not quite sure; I think it might be because of the claim that one of the possibilities I’d suggested required invoking group selection to work (a claim which I’m not sure is valid, but I’m also not sure enough of my grounds to argue against). That’s the only reason I can think of...
For a species driven entirely by instinct, yes. But given a species that is able to reason, wouldn’t a “raiser” who is given a whole group to raise be more efficient than parents? The benefit of a small minority of tribe members passing down their culture would certainly outweigh those few members also having children.
This is a lot less motivation than for parents.
Well, for starter if you don’t die after mating you might be able to mate again.
According to my source, which is a blog comment that doesn’t site its sources, the death is a form of controlled cell-death and scientists have been able to remove the gene responsible and the resulting octopuses (or squid) can mate again later.
That is true.
This might—purely hypothetically—lead to a massive boom in octopus population, causing the octopi to eat everything edible, causing mass starvation.
Or it might be that octopi lack any form of parental instinct; that, six months after the babies are born, the parents see them as “food”, severely reducing the probability of there being another generation. (This would even be an advantageous mutation for octopi that die after mating, because it means that a given genetic line will work towards eradicating the children of any other genetic lines, giving their children less competition...)
Either way, until an octopus in the wild develops the “does-not-die-after-mating” mutation on its own (or possibly escapes from the lab, if what those scientists did is inheritable), evolution will do nothing to get rid of it. And once it does turn up in the wild—well, all else being equal, I’d expect that mutation would supplant the previous, “die-after-mating” model eventually… after a few thousand years or so. Evolution is not, by any means, a completed process.
This relies on group selection to work.
Why was this down-voted?
I’m not quite sure; I think it might be because of the claim that one of the possibilities I’d suggested required invoking group selection to work (a claim which I’m not sure is valid, but I’m also not sure enough of my grounds to argue against). That’s the only reason I can think of...
For a species driven entirely by instinct, yes. But given a species that is able to reason, wouldn’t a “raiser” who is given a whole group to raise be more efficient than parents? The benefit of a small minority of tribe members passing down their culture would certainly outweigh those few members also having children.