We did not expect it would turn to goats.
About 14 minutes into the interview, which is part of Tech Insider’s Innovators series, Tyson asked Gore about the ethics of biotechnology.
“We all have to be prepared to engage in conversations about some of the difficult choices that will become available to us, like trait selection, like crossing species boundaries,” Gore replied.
Then the former Vice President adds: “You know about spider goats?”
Tyson’s ears perk up. “Sounds… Interesting,” Tyson replies.
“You can splice the genes from orb-weaving spiders into goats and produce spider goats,” Gore explains, “which mercifully, look like goats.”
Gore is not making this up. The goats have four legs, two eyes, and by most accounts are average-looking goats. When the BBC visited the first herd of goats at Utah State University in 2012, they even had adorable names like “Pudding” and “Freckles.”
But they are special in one, very important way: They’ve been genetically modified to produce spider silk in their milk.
How to make spider-goat silk
The silk produced by golden orb weaving spiders is tougher than Kevlar but has the elasticity and lightness of of nylon.
That makes the silk a very valuable substance.
The trouble is that it’s impractical to raise spiders to produce enough for industrial use — it took more than a million spiders and 70 human workers working for four years to make a single 11-foot by 4-foot piece of fabric.
Also, the spiders have a tendency to eat each other.
So in the early 2000s, Canadian company Nexia Biotechnologies approached molecular biologist Randy Lewis, then at the University of Wyoming, to explore producing the silk through other means.
Nexia went out of business in 2009 and Lewis has since moved from Wyoming to Utah State University, but the spider goats he created are still alive and spinning. Lewis estimates they’re now on their eighth or ninth generation of the modified goats.
The modification process begins with a single gene — the silk-spinning gene of the golden orb-weaving spider in this case — which is added to goat DNA.
“You take an egg,” Lewis explains, “you take out the nucleus and chromosomes, [then] put in the chromosomes from the cell you did all the genetic manipulation in.”
When the egg grows, the genes divide and multiply — and with it, the gene that tells the goats’ body to produce the spider-silk protein. The gene is then passed on through the generations.
“The property of the fiber we’re spinning now is, at best, one-half to two-thirds as strong [as the spider silk,] but just as elastic” Lewis told Tech Insider during a recent phone call. (For the record, that’s still incredibly strong.)
Each goat, Lewis says, produces about an ounce of the protein per milking session, yielding several thousand yards of a single spider-silk thread.
And, it should be noted, the goats don’t excrete a single fiber — that would be weird.
The milk has to be separated and refined several times, then washed, freeze-dried, and turned into a powder. The powder can be spun into a fiber, or transformed into a coating or adhesive. (The milk isn’t ever kept for human consumption.)
While the silk may not ever be inexpensive enough for truly widespread use, Lewis said, there are some industries that will be willing to invest in a higher quality, if higher priced, material.
What to do with spider-goat silk
In December 2015, Utah State University announced it had landed a $1 million contract with the Army to produce the silk. Textiles woven from the silk are lighter than Kevlar, and, unlike nylon, don’t melt, making it an attractive material for body armor.
But Lewis pointed out that there is also exciting potential in medical technology. The human body doesn’t reject the fiber like it does other materials. The silk could be used for sutures, skin grafts, or for complex jaw repair-surgery.
Lewis is also experimenting with other organisms that might be able to help produce dragline silk: silkworms, alfalfa, and bacteria, to name a few. But none of them, he said, have seen the same level of success as the spider goats.
The spider goats have their detractors, who say it’s “fundamentally wrong” to manipulate animals like this. Lewis counters by pointing out that people have basically doing this since they started domesticating and breeding animals.
He calls his research “precision genetics” — changing just one gene to get a specific outcome — whereas for millennia, people simply bred animals together in the hopes the desired trait would appear in the offspring.
“Take a look at what people have done with dogs,” he said, pointing out that we’ve bred several varieties to the point of uselessness. “Nobody seems to say a word.”
Back in Tech Insider’s studio, Gore gives Tyson a questioning glance: “Are you okay with [spider goats]?”
“Completely!” The astrophysicist says.
Gore’s larger point is that while spider goats represent a small, mostly benign change that has huge potential to help people; we’re going to be faced with some hard questions when designer babies start hitting the scene.
But for now, Lewis and his caprine webslingers just might be the next big thing.