When octopuses rule the earth

The octopus is an alien, an utterly confused tabloid piece read. One of those English papers. It quoted a scientist. One never jokes like that to a tabloid. Of course, the piece ran riot across Facebook. It may have been old news about the octopus’ nervous system, a week or two old anyway, but no one had mentioned the alien quote. It must be an alien, a marine biologist said. Friends of mine posted this in all earnestness. A zillion objections ran through my head–DNA was one, why would an alien share so much DNA with sea slugs and clams and snails–but what really stuck out for me was an octopus’s life span. If it’s some sort of advanced alien they sure don’t live very long.

Most octopus live from six months to two years, though a few species live up to five years. That’s it. They reach the end of that span and the body ages to the point of death. I’d always thought that the tragedy of the octopus is that it’s life span is so short there’s no way for individuals to either acquire decades of knowledge or pass on a culture. Mating is usually the cause of death, indeed of the process of death itself, the males die within months, the females not long after the young hatch. Oddly enough, females do because they stop eating while protecting the brood, they’ve done experiments that led the females to resume eating right after egg laying which led to much longer life spans. Had there been a mutation that allowed a species to do what was done in the lab then imagine the difference…. Unfortunately, no such mutation occurred, or remained, apparently starving oneself to protect the brood has evolutionary advantages. (Nor has there been found a way to stop the male from aging suddenly after fertilizing.) So advanced invertebrate intelligence has been held back by invertebrate reproduction. Which always strikes me as incredibly sad.

Still…the octopus has been around for a quarter billion years, and mammals didn’t even exist a quarter billion years ago (we were still non-mammalian cynodonts, the mammal-like reptiles that fully mammalian cynodonts–that is, mammals–evolved from maybe 25 million years later). Life in the sea is far less dynamic and less dangerous than life on land. Species can survive vastly longer before extinction, and their environment changes much more gradually. Even today’s climate crisis won’t threaten the existence of octopus species in the long run–after all, they emerged about the time of the Permian Extinction and glided through the end of the Cretaceous, when the planet was smacked by a giant meteor and rent by massive vulcanism at the same time. So octopus species–there are about three hundred known now–are quite likely to be on the planet for a long, long time.

And all it might take in that long, long time is a genetic mutation that, say, delays the onset of reproduction by a few years, long enough for octopus culture to increase in complexity and be learned by other observant octopuses, and then that more complex culture giving enough of an evolutionary advantage so that the mutation would not die out competing with octopus who reproduce at the current age. It was Homo habilis, a couple million years ago, who first began human culture in proto-human form, making tools from rocks by methods that would have required careful watching to master. Doesn’t this happen among some octopus species now? This would certainly have to be learned. The beginnings of culture are there already, and Amphioctopus marginatus and some similar species from around the Pacific is at the same stage with their coconut halves that Homo habilis was 2.8 million years ago shaping rocks into hand axes. Apparently one local population of Amphioctopus marginatus (or a related Amphioctopus species) figured out the body armor thing (perhaps using bivalves shells rather than coconut shells) just as a family or cave full of Homo habilis conceived the shaping of stones.

But while Homo habilis could live twenty, even forty years, Amphioctopus marginatus live from six months to a year. Imagine that–octopus have created and passed on tool using methods (by observing and copying) in a life span that, for any homo species, would scarcely go beyond infancy. But there is nothing saying that a mutation that enabled a longer octopus life span can’t happen and survive long enough to create a new long lived octopus species. It doesn’t seem like it would be an impossibility. Indeed among cephalopods the nautilus lives twenty years or more (not that far from that of homo habilis), and doesn’t even reach sexual maturity until fifteen, or three times longer than the longest octopus life span. Nor does a nautilus die after a single reproduction. However, the nautilus is more similar to the cephalopods of five hundred million year old than to octopus (and squid and cuttlefish.) Either at some point the nautilus developed iteroparity (multiple reproductive cycles) and a longer lifespan, or octopuses (and squid) switched to semelparity (a single fatal reproductive cycle.) Either way, it seems that the chain of mutations to increase the octopus life span should be theoretically possible within the genome of the octopus. (Mutations do not materialize out of nothing, but have to be possible within the genes and possible growth rates already within the parents’ genome. You can see that range in sexually dimorphic human beings, a man six and a half foot tall flirting with a woman four feet ten.) So there’s nothing saying that a quarter billion years from now (as I said, evolution is a vastly slower process in the ocean than on land, where it took a mere thirty five million years to go from monkey to human being) a long lived species of octopus will not be the smartest thing ever on earth. Some of them are using tools already, and I know some humans that can’t even do that.

Octopus habilis.

One thought on “When octopuses rule the earth

  1. Pingback: So it turns out octopuses will never rule the earth. | Brick's Science

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