mark_pagel's picture
Professor of Evolutionary Biology, Reading University, UK; Fellow, Royal Society; Author, Wired for Culture
Designer Humans

The use of CRISPR (clustered regularly interspaced short palindromic repeats) technologies for targeted gene editing means that an organism's genome can be cheaply cut and then edited at any location. The implications of such a technology are potentially so great that "crisper" has already become a widely-heard term outside of science, being the darling of radio and television talk shows. And why not? All of a sudden scientists and bio-technologists have a way of making designer organisms. The technology’s first real successes in yeast, fish, flies and even some monkeys have already been widely trumpeted.

But, of course, what is on everyone’s mind is its use in humans. By modifying genes in potential mother’s and father’s egg or sperm cells, they will go on to produce babies "designed" to have some desired trait, or to lack some undesirable trait. Or, by editing genes early enough in embryonic development—a time when only a few cells become the progenitors of all the cells in our bodies—the same design features can be obtained in the adult.

Just imagine, no more Huntington’s, chorea, no more sickle-cell anemia, no more cystic fibrosis, or a raft of other heritable disorders. But what about desirable traits— eye and hair color, personality and temperament, and even intelligence? The first of these—eye and hair color—are already easily within CRISPR’s grasp. The others are probably caused only partially by genes anyway, and even then potentially by scores or possibly hundreds of genes, each exerting a small effect. But who is to say we won’t figure out even these complicated cases one day?

To be sure, the startling progress that genomic and biotechnological workers have made over the last twenty years is not slowing down, and this tells us that there is good reason to believe that, if not in many of our own lifetimes, surely in our children’s, the information of how genes influence many of the traits we would like to design into or out of humans will be widely available.

None of this is lost on the CRISPR community. Already there have been calls for a moratorium on the use of the technology in humans. But the same could have been said in the early days of in vitro fertilization (IVF) technologies, even if those calls didn’t always come from the scientific community. The point is that we have learned that our norms of acceptance to many technological developments get shifted as those technologies become more familiar.

My own view is that the current moratorium on the use of CRISPR technologies in humans won't last long. The technology is remarkably accurate and reliable and this is still very "early days." Refinements to the technologies are inevitable as are demonstrations of its worth in, say, agricultural and environmental issues. The effect of these will be to wear down our resistance to designing humans. Already, CRISPR has been applied successfully to cultured cell lines derived from humans. The first truly and thoroughly designed humans are more than just the subjects of science fiction: they are on our doorsteps, waiting to be allowed in.