Our DNA is amazing. And over the years scientists have discovered many fascinating facts about the genetic material in deoxyribonucleic acid (DNA). Here are ten especially interesting DNA facts.

1. Your DNA could stretch from the earth to the sun and back ~600 times.

If unwound and linked together, the strands of DNA in each of your cells would be 6 feet long. With about 30 trillion cells in your body, that means if all your DNA were put end-to-end, it would stretch over 67 billion miles. In comparison, the distance between Earth and the Sun is 93 million miles, and it’s “only" 3 billion miles between Earth and Neptune, the planet at the farthest edge of our solar system.

2. We're all 99.5 percent alike.

Of the 3 billion base pairs in the human genome, only about 0.5% tend to vary between individuals. While that 0.5% is still what makes us unique, it means we're all more similar than we are different. Studying where those 0.5% are located in the human genome is easier for researchers than to look at all 3 billion base pairs.

3. Genes make up only about 3 percent of your DNA.

Genes are short segments of DNA, but not all DNA is made up of genes. All told, genes are only about 1-3% of your DNA. The rest of your DNA code controls the activity of your genes. Your genes influence how you look, how you act, and even how susceptible you are to disease.

4. There’s no such thing as “junk" DNA.

When scientists were first studying DNA and discovered that only 1-3% of your DNA is made up of genes, they thought the remaining 98% might be “junk." It turns out that all this non-coding DNA is actually incredibly important. It plays a role in controlling the activity of your genes—when they turn on or off—and it can help the DNA keep its shape, along with many other functions.

5. The human genome contains 3 billion base pairs of DNA.

DNA molecules are shaped like twisted ladders—a structure also known as a double helix. And the rungs on that ladder are made of bases—adenine (A), cytosine (C), guanine (G), and thymine (T)—locked together in pairs with hydrogen bonds. The really cool part is, they pair up in a very specific way: “A" always pairs with “T," and “C" always pairs with “G."

6. Your traits are a product of your genes and your environment.

Some of your traits are controlled entirely by your DNA. But most of your traits are controlled by a combination of your genetic information and your environment. For example, your height as an adult is strongly influenced by your DNA. After all, tall biological parents tend to have tall biological children. But, early childhood nutrition also plays a big factor in how tall you become as an adult.

7. Most traits are controlled by many genes.

You’ve probably heard someone described as having the “tall gene" or the “fast gene." But in reality, most traits are controlled by lots of genes all acting together with very small effects. In fact, a trait like height is impacted by over 12,000 DNA variants.

8. You inherited exactly half of your DNA from each of your biological parents.

Each biological parent passes along a random half of their DNA to their child. This means you can trace things like your ethnicities, traits, and matches back to the parent you inherited them from. Because the DNA you inherit from your parents is a random half, it also means that your results can differ from siblings results.

9. Your DNA changes over time.

For the most part, your DNA is the same now as it was when you were a child, and will be the same when you are much older. But, throughout your life, your DNA acquires random mutations during replication that change your DNA sequence. Most of the time these changes are not noticeable. Additionally, your DNA has special protective caps made of DNA on the ends of the chromosomes, called telomeres. While you age, these telomeres shorten.

10. Your DNA could link you to places you'd never imagine.

A DNA test can tell you which world regions your ancestors may have lived in hundreds to thousands of years ago. For example, you could discover that approximately 11% of your DNA connects you to Norway and that you also have genetic connections to Central Oaxaca in Mexico, Inishowen in Ireland, and the early settlers of Western Pennsylvania.

Ready to try an AncestryDNA^® test? Your DNA may well surprise you.

References

Cooke, Emily. “How many cells are in the human body? New study provides an answer." Live Science. September 20, 2023. https://www.livescience.com/health/anatomy/how-many-cells-are-in-the-human-body-new-study-provides-an-answer.

“Genetics by the Numbers." National Institute of General Medical Sciences. December 8, 2023. https://www.nigms.nih.gov/education/Inside-Life-Science/Pages/Genetics-by-the-Numbers.aspx.

Genomic Variation Program. National Human Genome Research Institute. Accessed January 3, 2024. https://www.genome.gov/Funded-Programs-Projects/Genomic-Variation-Program.

"Scale of the Solar System." National Aeronautics and Space Administration. January 2015. https://www.nasa.gov/wp-content/uploads/2015/01/yoss_act1.pdf.

“What is noncoding DNA?" MedlinePlus. Accessed January 3, 2024. https://medlineplus.gov/genetics/understanding/basics/noncodingdna/.

Yengo, L., Vedantam, S., et al. “A saturated map of common genetic variants associated with human height." Nature. October 12, 2022. https://www.nature.com/articles/s41586-022-05275-y.