My head is full of troubling thoughts ensuing from a book I just finished reading: A Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution by Jennifer A. Doudna and Samuel H. Sternberg. (I just realized that Jennifer’s family name could be read as “Do DNA,” which is strangely apt.)

This tome is strongly recommended as a good read, but not if you want to sleep soundly at night. For example, it’s weighing on (what I laughingly call) my mind that the biotechnology discussed in this book could lead to the end of human life as we know it. Since this is somewhat scary, my mind is trying to distract me with things like the Spock quote from Star Trek: The Original Series, “It’s life, Jim, but not as we know it.”

Sad to relate, Spock never actually said this. Also, Captain Kirk never said, “We come in peace; shoot to kill,” although this did occasionally reflect the good captain’s trigger-happy approach to alien encounters. In fact, both of these pseudo-quotes originated in the 1987 song Star Trekkin’ by The Firm.

This song also contained real lines from the series, such as Uhura’s “There’s Klingons on the starboard bow!” and Scotty’s “Ye cannae change the laws of physics!” As an aside, did you know that Scotty was actually played by Canadian actor James Doohan (more delightfully diverting details are divulged in my Beam Me Up Scotty blog).

The problem with this song is that the words and tune start rattling around in your head and they won’t stop. As one of the commenters to the video said, “I never knew you could love and hate a song at the same time so strongly.” On the bright side, it serves as a distraction to the aforementioned book…

…and we’re back!

Did you know that, when measured in terms of gigatons of carbon (Gt C), where carbon is the signature element of life on Earth, all humans combined would weigh 0.06 Gt C. If we include all of the other animals (arthropods, fish, mollusks, annelids, livestock, nematodes, wild mammals, and wild birds), we reach 2 Gt C, which may seem like a lot until you realize that bacteria weigh in at 70 Gt C (more details are available in the All Life on Earth article on Vox).

As abundant as bacteria are, they are outnumbered ten-to-one by bacterial viruses. Known as bacteriophages, or phages for short, these viruses have evolved over billions of years to attack bacteria with ruthless efficiency.

So, how do bacteria defend themselves against gangs of marauding phages? I’m glad you asked. As we learn in the aforementioned book, CRISPR (which is an acronym for clustered regularly interspaced short palindromic repeats) is a family of DNA sequences found in the genomes of organisms like bacteria and archaea. These sequences are derived from DNA fragments of bacteriophages that had previously infected the prokaryote.

In addition to the sequences derived from bacteriophages, there are additional sequences that form a molecular toolkit that bacteria use to detect and destroy DNA from similar bacteriophages during subsequent infections.

The point is that, in just the past 15 years or so, scientists have learned how to use CRISPR to insert, edit, or delete genes in virtually any living plant or animal’s genome.

On the one hand, this could lead to crops that can grow in increasingly extreme environments (e.g., hotter and drier), which will be useful as climate change continues to take its toll. There’s also the possibility of using this gene-editing technology to correct the mutations responsible for things like cystic fibrosis, sickle cell disease, and some forms of blindness, along with muscular dystrophy, multiple sclerosis, amyotrophic lateral sclerosis (ALS), Alzheimer’s, Parkinson’s disease… the list goes on.

But then we turn to the darker side of things. Suppose it becomes possible to gene-edit embryos to create “designer humans” — smarter, fitter, taller, thinner — just pick the characteristics that are of most interest to you. It will come as no surprise that rich people will be able to afford this sort of thing while poor people… won’t. Since we are talking about editing the germline, which means that these genes will be passed on to future generations, we could end up with a “gene gap” that would only widen over time. As Jennifer says:

If you think our world is unequal now, just imagine it stratified along both socioeconomic and genetic lines. Envision a future where people with more money live healthier and longer lives thanks to their privileged set of genes. It’s the stuff of science fiction, but if germline editing becomes routine, then this fiction could become reality.

The great thing about this book is that Jennifer explains everything is such a way that even a bear of little brain like your humble narrator can wrap their noggin around it. She also delves deep into the myriad possibilities, explaining their potential pros and conceivable cons without trying to persuade the reader as to a particular point of view.

I think we’ve already introduced enough ideas to be scared about without going further, but I simply cannot help myself. My problem is that I’ve read so many science fiction books and seen so many science fiction movies that I can envisage all sorts of dire consequences that could ensue from CRISPR-based gene-editing.

Suppose, for example, that some terrorist organization decides it would be a good idea to target a gene that is only found in tall, handsome, witty, English engineers (I’m just picking an example out of a hat, you understand), and — to this end — they create a CRISPR-based bioweapon designed to remove us from the face of the planet. Seriously, it’s not beyond the bounds of possibility that one group of people who loath another group of people could attempt to isolate some sort of gene sequence that could be used to target subgroups of the population.

I’m shaking my head in disbelief that I’m even thinking such thoughts, but I fear there are people out there who would happily “Cry havoc and let slip the CRISPR dogs of war.” What say you? Do you have any thoughts you’d care to share on any of this?