Now, let me explain. The context is that I have a species called the Aviares that have very brittle bones, so they can fly. Is it possible for them to be genetically modified to have their bones be made from an alloy, and if they take supplements of said alloy, would it work?

Update: I just started my chatroom called The Council Of Devourers, for discussing the creation of my universe.

Update 3: The Council of Devourers is closed now. No further discussion shall occur.

  • $\begingroup$ So you want to have a biological process that can grow material which is considered non-biological? $\endgroup$ – Alexander Mar 9 at 22:14
  • $\begingroup$ Yeah, pretty much. $\endgroup$ – The Sophomore Mar 9 at 22:15
  • $\begingroup$ honestly, lets just say alloy then. $\endgroup$ – The Sophomore Mar 9 at 22:34
  • $\begingroup$ this really depends on the alloy, many materials are not bio-compatible, although there are not many alloys that would be stronger than the composite that already makes up bone. $\endgroup$ – John Mar 10 at 5:42
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    $\begingroup$ Bone has a tensile strength comparable of aluminum alloy (6061) in the direction of natural loading. $\endgroup$ – John Mar 10 at 6:00

Living things use externally sourced materials very often and biological systems use minerals and complex compounds taken wholesale from food.

So, it's entirely possible and precedented that an organism will make use of an externally supplied material that has the required chemical or biological binding properties it needs for a process, even if that substance has never been used by the species previously.

The first thing I thought of when reading the question is the deep-sea snail that incorporates iron sulfide into its shell and foot. They live near thermal vents where the required material occurs naturally and they incorporate it into their physical makeup in a way that is not similar to other species in their biological group. Some really cool photos in image search.


Another example is the poison dart frog famous for its toxic secretion which it doesn't produce itself. They get their defining defense from eating organisms that do sythesize the poison. In captivity they continue to function without being poisonous.


  • $\begingroup$ The snail was the first thing that hit my mind too, calcium is a metal anyway so the extant processes shouldn't need a lot of tweaking, I think that snail' i pretty good evidence for that supposition ... gene engineered golden egg laying Geese anyone? $\endgroup$ – Pelinore Mar 10 at 11:33
  • $\begingroup$ @Pelinore Less work to just make a golden egg than solubilize gold for the geese (and less toxic). But bio-engineered metal-refining geese eating industrial slag and laying golden eggs is another thing all together... $\endgroup$ – DWKraus Mar 31 at 20:43
  • $\begingroup$ @DWKraus There's about one gram of gold for every 100 million metric tons of sea water, about 0.2 milligrams of gold in an adult human body weighing 70 kg so it's there in the environment & normal food in micro amounts, we use it in joints & nerves, presumably Geese do too .. so all we need do is encourage greater uptake & laying it down in egg shell, could probably be done by ordinary selective breeding if you had enough time, the shell would be mostly calcium with very very small flecks of gold, gold content isn't going to be much .. no diet of industrial slag required. $\endgroup$ – Pelinore Mar 31 at 20:53
  • $\begingroup$ @DWKraus Just did the math .. 5 thousand people gets you a gram of gold .. I'm off to seek psychiatric help now, it can't be normal wondering about that ;) $\endgroup$ – Pelinore Mar 31 at 21:01
  • $\begingroup$ @Pelinore Is it wrong that I like people who wonder about stuff like this? $\endgroup$ – DWKraus Mar 31 at 21:07

There are difficulties for sure.

There are a few hypothesis for why we do not see pure metal elements or alloys in biology:

  1. They cannot be grown or maintained easily through biological processes (or maybe just take too much energy to process into pure elemental forms). You might have to resort to scaffolding mechanisms similar to your tooth enamel which is grown from a scaffolding which is then discarded and afterwards grows no more.

  2. Metal is scarce. Iron is considered abundant but we still go through a lot of raw ore to come up with enough metal. Biology tends to use far more common elements such as hydrogen, carbon, and nitrogen, and oxygen only mixing in the scarcer elements as required.

  • $\begingroup$ The scarceness of the material does not matter, since they are taking supplements of the required material. $\endgroup$ – The Sophomore Mar 9 at 22:39
  • $\begingroup$ @Korblox Then you only really have the first issue which you might be able to hand wave away with superior knowledge of molecular engineering. But as things stand, our understanding, let alone ability to implement, molecular machinery is rather limited and we've not observed too many chemical tricks that can be used to manipulate pure elements and leave behind pure elements. Biology as we know it uses the lighter elements to produce a living material that can grow, or uses them as an scaffolding which is either behind internally or removed externally (teeth). $\endgroup$ – DKNguyen Mar 9 at 22:47
  • $\begingroup$ Frankly though, I think if you have the understanding to do that though, you are not that far away from making whatever lifeforms you want, carbon-based or not. For example, humans in Xenosaga are able to build Realians which are living organisms made from whatever base elements they want because they have complete understanding and manipulation of molecular machinery. Genetic engineering is just a tiny subset of molecular engineering. $\endgroup$ – DKNguyen Mar 9 at 22:49
  • $\begingroup$ You do know calcium is a metal right? $\endgroup$ – Pelinore Mar 10 at 11:37
  • $\begingroup$ @Pelinore Actually I wasn't aware. That's very interesting that our bodies use so much alcium when it is less abundant than aluminum and iron. I'm assuming it is because it presents itself as a more easily processible form in nature. $\endgroup$ – DKNguyen Mar 11 at 1:55

Organisms in our world already use inorganic materials (like metals) in biological processes. If you’re happy to do a bit of handwaving I don’t see any reason you couldn’t have an engineered protein(s) which is very efficient at sequestering a metal alloy and using it to build up bones. After all, our bones contain a lot of calcium which is inorganic.

The only thing I’d say to watch out for is that bones made purely from metal alloys might have unintended effects...


Look at the way bone grows now: the mineral part is not made of cells, but rather you have cells that crawl over it pulling up old material (osteoclasts) and secrete new material (osteoblasts), pretty much the way our heavy machines maintain asphalt roads.

Your guy can have nanobots that are not related to his natural cells, which have these roles, but use different material. If it's graphene or otherwise uses the kinds of atoms present in our bodies anyway, you're good to go. If it uses aluminum or other atoms that are not already being distributed by the blood, you also need to add infrastructure for this.


Metal alloy bones, it's an interesting idea for sure. I think it would be unlikely for species to produce bones of a metal alloy even when taking supplements. But there might be a substitute that could work and allow for supplements. I suggest that through genetic modifications the Aviares could potentially grow an exoskeleton-like structure around their brittle bones. While exoskeletons are usually external to the body. I see no biological reason that genetic modifications would not allow for a strong exoskeleton to form internally around the bones. You also wouldn't need to deal with any potential health problems since the exoskeleton would be organic but might require certain supplements to keep it from softening up.

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    $\begingroup$ Exoskeleton is a word that literally means external skeleton, what you're talking about is internal ergo not an exoskeleton by definition. $\endgroup$ – Pelinore Mar 10 at 11:40
  • $\begingroup$ That is true, I called it an exoskeleton for the lack of a better description. $\endgroup$ – Morten Kristensen Mar 11 at 3:34

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