today we’re going to discuss a somewhat unusual but also somewhat unnerving report that talks about potential dangers for what’s known as mirror life, or specifically mirror bacteria. Though as I describe this to you, it might sound like some kind of science fiction scenario, turns out that this could actually be an extremely dangerous phenomenon for the future of the planet and something that a lot of scientists are now officially warning about. Here we’re actually talking about something that would be a new extinction event if this ever became real. Let’s discuss this in more detail, but let’s start with the basics of biology first. Let’s talk about chirality and handedness of molecules and why it’s important.

Chirality is a topic you might remember from basic biology, the idea that things tend to come in two different shapes: either left-handed or right-handed. It’s a type of asymmetry that applies to many different sciences, with the most famous example usually being our hands. Both are mirror images, but this idea of handedness is particularly important in organic chemistry. Mirror molecules usually form in equal amounts but can have extremely different effects and functions depending on their handedness. A famous example is the molecule carbon, often used in various biology and chemistry classes. Carbon also comes in left-handed or right-handed forms, and depending on the handedness, it can either smell like spearmint or a seed known as caraway. In other words, mirror molecules react differently inside our nose, attaching to different scent receptors, making them smell differently.

While this is a simple example, some cases are more extreme, and it doesn’t get more extreme than thalidomide. Thalidomide was an extremely powerful drug prescribed many years ago as a treatment for morning sickness, and it worked very well. However, one of its forms caused devastating birth defects, which wasn’t known until it started affecting pregnant women and their children over the years. Examples like thalidomide show how extreme this can get and how handedness can be very dangerous. But they also show us that this is something we can physically create and control.

Recent advances in biochemistry have made the generation of mirror molecules and mirror peptides even more popular. For instance, a paper from January 2024 sequenced a mirror image of a large ribosomal protein, a technique that could have many medical applications. By creating a mirror version of a protein, it might be possible to create something that can function as a medicine or destroy viruses and bacteria in our body without being detected by our immune system, thus functioning much longer. This idea started back in 2016 when Harvard scientist George Church created a mirror version of a DNA polymerase. While this was based on curiosity, it has advanced rapidly, and now many scientists are warning about its dangers.

The concern comes from studies mixing synthetic cell engineering and nanotechnology to combine mirror proteins and potentially create mirror life, or at least mirror bacteria. Researchers have already been successful at creating synthetic bacteria through genetic modification, a field known as synthetic biology that began in the '80s and is now quite advanced. Some scientists are now combining these fields to create mirror bacteria—synthetic life formed from mirror molecules and proteins.

It’s crucial to understand something about life as we know it: all of the amino acids inside us and the building blocks of proteins are left-handed, while all sugars are right-handed. DNA is also right-handed. This selective chirality is important because it’s a defining feature of life and influences all chemical reactions in living organisms. But what if bacteria or viruses were made entirely of left-handed DNA? If such mirror life forms existed, our immune systems would be powerless against them because our bodies wouldn’t recognize them. Additionally, viruses that normally control bacterial growth wouldn’t work on these mirror bacteria, and no digestive enzymes could break them down.

If mirror bacteria escaped a lab, they could displace natural bacteria, collapse ecosystems, and potentially become immune to anything in nature, leading to an extinction event. With no predators, no viruses, and no enzymes able to affect them, they could take over the planet. While this might sound like science fiction, it’s a real possibility, and scientists are concerned about the unpredictable effects.

Antibiotics we use today depend on the chirality of molecules, and in the event of mirror bacteria, we wouldn’t have anything to fight them. While we’re still at least a decade away from scientists being able to create a fully functioning organism made entirely of mirror molecules, it’s something that is technically achievable. The report warning about this is extremely detailed and runs through various scenarios. It highlights how mirror bacteria could become dominant and disrupt ecosystems, which could potentially lead to catastrophic consequences.

Hopefully, scientists will exercise caution when working with mirror life and bacteria, but if they don’t, we could face a problem that we can’t fight or even see coming. It’s a fascinating concept, and we’ll keep following this idea in future videos. For now, let’s dive into chirality and the origins of handedness in life, which will be discussed further in the videos in the description. We’ll return to this topic once more discoveries or safety measures emerge.