We tend to think of our bodies as “ours.” And not just our arms and our legs—the thoughts in our heads, the blood running through our veins, the stomach that processes our food, are ours, wholly ours, and nothing but ours.

But is that really the case? As but one example, your “body” actually includes 10-100 trillion microbiota, which (depending on how you count) is up to ten times the number of cells of your own DNA. So how much of “you” is really you, and how much is, say, just a house for bacteria?

Let’s push that a little further. What if it was not microbiotic DNA inhabiting our bodies, but sheep DNA? Would we then think of ourselves as part-human, part-sheep? And now let’s complicate that even more: What if using animal DNA helped alleviate the challenge of finding suitable organ donations for humans who are in desperate need of them?

These questions are becoming closer and closer to reality. In a National Geographic article about sheep-human embryos made in a lab, Michael Greshko writes: “Every hour, six people in the United States are added to the national waiting list for organ transplants—and each day, 22 people on the list die waiting. In the U.S. alone, more than a hundred thousand people need heart transplants each year, but only about 2,200 receive one.”

In response, researchers are working to artificially expand the organ supply. Some are trying to 3-D print organs in the lab. Others are working on artificial, mechanical organs. And some are making chimeras—hybrids of two different species—in the hopes of growing human organs in pigs or sheep.

As medical technology advances, and a desire to gain much-needed organs, some people would certainly accept animal DNA as part of their body. On a rational, cost-benefit analysis, it’s almost a no-brainer to do this, especially because our bodies aren’t just “us” but house all kinds of other living things. Why should a sheep heart be any different from a microbial organism?

To read more, please go to Orbiter.