Transitioning from cloning animal embryos to human ones has proven far more controversial, and not only because of the litany of risks involved. So far, scientists have only gone as far as to generate human embryo models grown stem cells and clone primates from fetal cells — rather than adult cells, like Dolly.

That hasn't stopped some from exploring the idea as part of a secretive effort to realize an alternative to anti-aging tech that sounds like it was ripped straight out of a dystopian science fiction novel. A billionaire-backed stealth startup, called R3 Bio, recently announced that it was raising money to develop non-sentient monkey "organ sacks," as Wired reported last week, an eyebrow-raising alternative to animal testing. Such structures would contain all typical organs excluding the brain, ultimately serving as a source for donor organs and tissues.

But according to a sprawling followup investigation by MIT Technology Review, R3 Bio's founders secretly have a far more ambitious goal in mind: creating entire "brainless clones" of the human body that aging or ill individuals could one day transplant their brain into. One advantage of not developing the brain in the donor bodies, albeit a ghoulish one: such a brain-free clone would neatly circumvent certain moral conundrums over the concept.