BioSteel is a substance produced by goats whose DNA has received the silk-producing genes of spiders.

While silkworms are generally social creatures, spiders are reclusive, meaning they cannot be farmed effectively for their strong silk. However, when silk-producing chemicals can be made "naturally" by a goat, and excreted through its milk, the silk can be farmed easily. It is estimated a single goat is capable of generating enough silk in a day to spin 34,000 meters of BioSteel thread.

When refined, BioSteel is incredibly strong, compared to more common metal alloys, such as steel, whilst still retaining a remarkably high flexibility and durability.

But how and why would something evolve, naturally, to produce so much of this substance?

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    $\begingroup$ They might, theoretically, use it to spin webs and trap insects. $\endgroup$ – IndigoFenix Nov 21 '16 at 6:29
  • $\begingroup$ @IndigoFenix That is possible but why would the compound need to be so strong? $\endgroup$ – Zxyrra Nov 21 '16 at 6:30
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    $\begingroup$ It already is. Biosteel is literally just spider silk. Actually real spider silk is even stronger than biosteel, because the spinnerets wind the proteins as they harden. So there already is an organism that naturally makes biosteel - spiders. They just don't make it for us. $\endgroup$ – IndigoFenix Nov 21 '16 at 6:49
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    $\begingroup$ @IndigoFenix Perhaps, really big spiders. $\endgroup$ – a4android Nov 21 '16 at 9:42
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    $\begingroup$ "If you're going to do something, do it right" is my editing motto. Those added pieces of information are nothing more than re-wording/extension of your own statements, an example being the DNA splicing bit (which is now formatted with the correct genetic terminology), to make the text smoother to read/interpret. The silk meterage was just a cool fact really to help bolster the overall "wow!" of BioSteel™ manufacturing. I meant no offence to you in editing your piece, having wanted only to make an already interesting question/concept even more well-recieved and successful on this site. :) $\endgroup$ – Harry David Nov 22 '16 at 0:57

You would need an environment where some form of predator needs a new niche in the food chain. Perhaps some other form of predator decimated the prey of a certain size very much and what's left is either too big or too fast for our ancestor creature.

It could just become extinct. But there might be mutations that manage to survive, now being the fittest to survive a new race develops from our ancestor.

One such mutation might be the ability to spit/launch strands of web-like substances at prey that would otherwise be too quick or too dangerous to our predator.

In the same vain a prey creature could develop it as a defensive weapon to drive off predators like Bombardier beetles do with their defensive secretions.

It seems that the slime produced by Hagfish has fibres in it that resemble spider silk (I could find this resemblance mentioned in the German wiki entry but not in the English one, where they only mention "hagfish slime filament protein" as being researched). This indicates that larger creatures and such of different species can use similar materials for defence.

Just for reference the German passage mentioning it:

Kürzlich wurde zudem entdeckt, dass der Schleim, den Schleimaale abgeben, strukturell einzigartig ist, da er reißfeste, fadenförmige Fasern enthält, die chemisch gewisse Ähnlichkeiten mit denen der Spinnenseide aufweisen.

Schleimaale = Hagfish / Spinnenseide = Spidersilk

I hope this doesn't violate the English speaking nature of this SE.

Loosely translated it means: The slime secreted by hagfish is structurally unique as it contains tear-resistant threadlike fibres that have a certain chemical similarity to those of spider silk.


As natural defense.

You probably want something different from a spider so how about a herbivore that weaves itself an exoskeleton out of biosteel? Something like an armadillo or lobster, but instead of thick skin/bone the make their own plate armour with biosteel weave. When it outgrows its armour the creature could shed it, making farming the biosteel in large amounts possible if need be.

Edited for improved clarity

Why do certain creatures have armour? To defend against predators. As predators evolve to get past this (larger jaws, prying claws), the creature will need to evolve a more durable/impenetrable solution, thus resulting in the answer I gave.

Or if you are completely sadistic, you can always have spiders covered in biosteel-woven plates. That would be terrifying....

  • $\begingroup$ I don't think this is a viable answer to the question, since id does not address the question how this behaviour could evolve. $\endgroup$ – Burki Nov 21 '16 at 13:48
  • $\begingroup$ @Burki. I edited my answer, but the fact that I stated a herbivore and referenced the armidillo makes it pretty self explanatory. Carnivore eats herbivore. Herbivore evolves defences, carnivore evolves a way around them. This cycle repeats until the herbivore develops the required trait or goes extinct. $\endgroup$ – Lu22 Nov 21 '16 at 13:59
  • $\begingroup$ Imho that still does not answer the "how"-part. To do so, it would be required to describe at least some of the steps from a creature without that ability to one that has it, with some reasonable hints at why the gradual changes provided an advantage. Evolution only favours local maxima, so the steps towards this ability each need to be beneficial, or may at least not be disadvantageous and must still prevail to improve later. $\endgroup$ – Burki Nov 21 '16 at 15:08
  • $\begingroup$ It's nitpicking to be honest. No one said the creature was without the ability in the first place. This being Xenobiology try to picture a caterpillar like creature that weaves a cocoon at maturity. But instead of leaving the cocoon after metamorphosis it stays inside the protective shell, until it outgrows it and must weave a new one. Happy? $\endgroup$ – Lu22 Nov 21 '16 at 15:46
  • $\begingroup$ "probably want something different from a spider" Not necessarily but either is fine. Interesting ideas presented, thank you. $\endgroup$ – Zxyrra Nov 21 '16 at 16:41

Bird catcher arachnids. If the spider like species need to catch birds in the forest then they might need stronger webs. This in time might result them to develop biosteel.

Edit: Forgot the how part. They will simply evolve from spiders. If some sort of mutation allows them to catch larger prey, they will survive better and evolve to have stronger silks. This in time might produce biosteel.


beavers incorporate iron into their teeth to make them harder, eventually this could lead to a steel like substance, highly specialized for hardness. then it's just a matter of moving the genes to goats.
if you need a strand like origin, the anchoring strands of some mollusks contain the strongest adhesives in nature, so maybe they need stronger fibers as well.

The strongest spider silk (and strongest organic fiber known and much stronger than kevlar) is produced by spiders that weave webs across entire rivers, the Darwin's bark spider. To get a super fiber just ramp it up to spiders who weave webs across entire canyons.


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