6 ms·
They have a gland or something that kills them before they live longer than a few years. The specifics probably vary.
by ianai 6y ago
They have a gland or something that kills them before they live longer than a few years. The specifics probably vary.
- swyx 6y agowhats the evolutionary reason (i know there doesnt have to be one) for something like that?!
- phkahler 6y ago>> whats the evolutionary reason for something like that?! You can never really know the reason with evolution because every plausible effect is in play and part of the optimization process. Having said that, one reason for adults to die may be to conserve resources (food) for the young in times/areas of scarcity. Another may be to prevent excess breeding by an individual, which may reduce genetic diversity. There are probably other viable reasons as well.
- jbay808 6y ago> Another may be to prevent excess breeding by an individual, which may reduce genetic diversity. That sounds like group selectionism. In what circumstance would this be deleterious to the propagation of that individual's genes?
- reason-mr 6y agoSurely if genetic variation is introduced primarily by the breeding process, any factors which have a effect against like (competing for food, less genetic variation), etc, are going to get selected against? I have always thought this was the reason behind human lifespans - in neolithic times, up to 33 years. Just enough time to mate and raise another individual to maturity.
- MayeulC 6y agoLesser genetic diversity is always bad for survival: with clonal species like the bananas we cultivate, for instance, a single pathogen can endanger the whole population. The less diverse the population, the less likely timely mutations will help protect it. Incidentally, our modern society is pretty diverse, especially as we protect those who couldn't otherwise survive without modern medicine.
- jbay808 6y agoNo disagreements there, but adaptations that are advantageous for the population as a whole won't necessarily spread through a population. https://www.lesswrong.com/posts/QsMJQSFj7WfoTMNgW/the-tragedy-of-group-selectionism https://www.lesswrong.com/posts/QsMJQSFj7WfoTMNgW/the-traged...
- MayeulC 6y agoAh, I better see your point. Well, that adaptation has to be selected for at some point of course. Among a single species, with a 50/50 split of a genetically diverse and homogeneous population, if you eliminate 10% of the former and 75% of the latter, the split becomes 80/20. If that distinction stemmed from genetic factors, you have selected for diversity. Genetic diversity isn't only advantageous to the population. It's advantageous for the individuals that carry it, depending on the circumstances. Therefore it can easily be selected for.
- KSteffensen 6y agoI've heard a theory that they are cannibals and would eat their young.....
- watersb 6y agoTeleology != Ontology There doesn't have to be a use for an evolutionary trait. It can be an utterly useless feature. The fact that it persists in this fleeting moment we co-exist with it in this particular million years, only shows that a feature hasn't been rendered extinct. Yet. But of course, I believe that biologists can construct a cladistic tree that can calibrate how long a particular trait might have been around.
- howlgarnish 6y agoOdds are it continues to serve some useful purpose though. Us humans have a whole lot of useful organs, and only one vestigial appendix.
- robocat 6y agoThe appendix has a purpose: https://www.scientificamerican.com/article/what-is-the-function-of-the-human-appendix-did-it-once-have-a-purpose-that-has-since-been-lost/ https://www.scientificamerican.com/article/what-is-the-funct... And another suspected purpose: https://www.webmd.com/digestive-disorders/news/20071012/appendix-may-have-purpose#1 https://www.webmd.com/digestive-disorders/news/20071012/appe...
- Simon_says 6y agoThe cool thing about the Internet is there are people of all different levels of knowledge about a subject writing comments on that subject.
- rikroots 6y agoI googled "why do octopuses die so young" and came up with this article: https://www.sciencealert.com/mother-octopus-senescence-death-after-mating-eggs-reproduction-rna-sequence-optic-gland https://www.sciencealert.com/mother-octopus-senescence-death... > The maturation of the reproductive organs appears to be driven by secretions from the optic gland. These same secretions, it seems, inactivate the digestive and salivary glands, which leads to the octopus starving to death. > In 1977, researchers removed this gland and found that the octopus' mothering instincts disappeared. She abandoned her eggs, started feeding again, and went on to live a much longer life. As a reproductive strategy for an (arguably) intelligent animal ... this makes me feel sad. However there's plenty of octopuses around so in evolutionary terms it's a strategy that works. As for the males - and this is the point at which my anthropomorphic 'yuk' reflex goes into overdrive - they die soon after their first successful sexual encounter. Males store sperm in one of their arms. For some species, 'sex' involves detaching that arm and giving it to the female to keep for later use. Then they wander off and die. Possibly from disappointment.
- swyx 6y agoi mean.. i feel for all my octopus brothers. i would too.
- blnqr 6y agoOnly the good die young
- Thlom 6y agoThere's a Radiolab episode about this. An Octopus mother brooding her eggs for month on end and then dying just when the eggs hatched. Episode title is Octomom.
- shard 6y agoSounds like female octopus with the gland removed could be a good pet. It's like spaying a cat.
- megablast 6y agoSure, lets disable animals for your amusement.
- JoeAltmaier 6y agoOctopi are easily damaged. Perhaps to keep the population fit, by frequently turning over older (damaged) members.
- clort 6y agoOne other evolutionary reason is that octopuses lay 20-100 thousand eggs that one time. They really don't need to carry on and produce another batch. Of course, most of those larva are eaten before they make it to maturity, just like many other sea creatures..
- thechao 6y agoI read an entire book on this! It’s because their expected time-to-predation is very short. Genes that are deleterious to long life-span aren’t selected against and, thus, accumulate. (“Other Minds” by Peter Smith.)
- chrisco255 6y agoAre whales their primary predators?
- steve_adams_86 6y agoI know sharks are a significant predator where I live and in places I’ve seen in documentaries. I’d assume that’s the case around all of the oceans since sharks and octopuses occur together everywhere. I’m not sure if that’s the case in the deep sea, though.
- pvaldes 6y agoProbably not. I had found a few octopus in cetacean's stomachs, but they prefer squids. Gregarious and much more convenient to hunt. Seals on the other time... Yup; I can tell you than monk seals definitely eat octopus.
- thechao 6y agoThe octopuses the author studied were shallow-water reef dwellers. They were predated by fish, mostly.
- nkingsy 6y agoNow I have to figure out how to work "expected time to predation" into a sentence. Maybe the next time I eat the last cookie.