Engaging geneticist Adam Rutherford checks in on the exciting field of synthetic biology, where new organisms are being created through the manipulation of genetic code, and discovers some startling developments, such as a goat spliced with spider genes whose milk can be used to spin silk.

When it comes down to it, they're just normal goats with one spider gene in them.

How does a spider gene get into goat milk in the first place?

The baby goat will have a spider gene present in each of its cells (its eyes, ears and hooves will all be part spider), but only in the mammary glands of female goats will the silk gene actually spring to life.

The Journal of Experimental Biology relates spider genes, proteins and silk from fibroin sequence to mechanical function.

By splicing a spider gene into a goat, for example, scientists in Montreal have produced a material strong enough for bulletproof vests.

Army researchers from the Medical Corps were trying to replicate the chemistry of the spider gene to produce the silk manufacturing protein.

In the mix-and-match game that has given us goats with spider genes (to make silk in their milk), pest-resistant cotton and so-called Frankenfoods, one of the latest innovations has been to tinker with salmon genes to make the fish grow faster.

"Pregnancy iss de mosd awful criminal form uf insanity because uf de black widowed spider gene t'eory uf woman's evolution!"

The goats with spider genes and silk in their milk.