Because I need a spine that works for massive and small creatures I'm thinking of making a plant-based spine (which has its own DNA). The spine acts kind of like a cucumber, in that when it sucks up more water it becomes sturdier, but when it loses water it becomes soft and malleable. A system of muscles squeezes on the spine to make it lose/gain water, like a sponge.

Because these creatures are humanoids, I figured I could put some form of photosynthetic hair on them, like a root comes up through the neck and sprouts out of the skull, allowing the spine to get all of the light it needs to grow with the organism.

Is this feasable? And, if so, what do you think the hair would looke like? (more like wide flower leaves, pine needles, or perhaps even hair-like?)


I like this idea. I am mildly confused why you are comparing the spine to a cucumber rather than to existing human structures that firm and lengthen in response to proper stimulus. No matter.

Some animals (notably the sea slug Elysia chlorotica) become photosynthetic following an algal meal. The mechanism is an area of active study.

Perhaps when your creatures need to photosynthesize they ingest algae, sprout hair and capture sunlight.

Green hair is currently en vogue, so even though flat leaves are better designs I'd probably opt for hair.

  • $\begingroup$ Thanks for the link, it's been helpful in design. Also, algae is an essential part of their diet, so this would make a lot of sense. I appreciate the comment! $\endgroup$ – Xivote Aug 28 '17 at 0:13

Does the spine need to have separate DNA? It might be much simpler if these creatures evolved chloroplasts by themselves or by absorbing algae. What I'm saying is that if it's not a hard requirement, don't have the spine be a separate organism. Heck, even humans have ... organs which vary in rigidity based on liquid content. (I'm being as delicate as I can here)

An interesting side-effect of this might be that your creatures only keep their spine rigidity when they need/want it. They might spend half their time being soft and malleable like molluscs. Huge implications for their architecture, if nothing else.

Now moving to the hair ... Check out this page as a reference ( https://www.hunker.com/13428809/what-is-the-difference-between-needle-leaf-and-broad-leaf-trees ). Takeaway is that broadleafs are better photosynthesizers but require more water. Needle-leafs aren't as efficient as sugar production, but are way more efficient w.r.t. water loss. You might want to have both types on your people, depending on their original climate.

Further note ... don't look to photosynthesis to solve everything. It would take an impractical amount of green hair to make a person carbon neutral (ie sugar neutral as well). What it can do is stretch out the time before you starve to death. So maybe this hair evolved in an area with marginal life support, where dearth is common, and even the tiniest edge might allow you to live til the next good season. So these days, maybe the well-fed yeomen look down on those who still rely on hair-support. The most grossly spendthrift wastrels in the big cities even get buzz-cuts to flaunt their wealth!

Whoah, went off on a big tangent there. But you've got two fascinating biological ideas going on there, have fun with them!

  • $\begingroup$ Wow, I didn't really think of that. This is why I love this forum, so many different ideas. Thanks for the comment! $\endgroup$ – Xivote Aug 28 '17 at 0:12
  • $\begingroup$ What's wrong with their fictional creatures being symbionts? As you no doubt already know, humans along with all plants and animals, are also symbionts, as they possess mitochondria with their own DNA. $\endgroup$ – AngelPray Aug 28 '17 at 9:01
  • $\begingroup$ Oh, there's no problem with the spines being symbionts. It's a question of whether it's key part of the story or background that they be so, or if anything which can get similar physical results will do. I was just pointing that out. Symbionts are great, especially if they talk back to you. I can just imagine if these guys' veggie-spines evolved the ability to speak. You could have a hero of these people who is simply -made- of courage, but his spine is a coward. Or is wanted for some crime which only veggie-crimes can commit. Or... ;D $\endgroup$ – akaioi Aug 28 '17 at 22:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.