Have you ever wondered why some people have blue eyes and some have brown eyes? Or why some insects fly while others crawl? Why are some fish are big and others small? It all has to do with our DNA.

Deoxyribonucleic (dee-OX-see-rye-bo-noo-CLAY-ik) acid, or DNA, shapes all life on Earth. It’s a microscopic bundle of molecules located inside the cells of every living thing—including you! This bundle of molecules contains genetic information that determines the unique characteristics and adaptations of every species on the planet—from eye color to blood type to whether a plant has leaves or thorns.

The information in DNA is stored as a very simple code made up of four chemical bases, known by their initials: adenine (A), guanine (G), cytosine (C), and thymine (T). The way these bases are arranged determines the code, or information, needed to build and maintain all of our bodies’ characteristics.  

You can think of it this way: The letters of the alphabet appear in a certain order to form words or sentences. Instead of 26 letters, DNA strands only have four (A, T, G, and C). However, these four letters can be linked up and arranged in millions and millions of different ways, so that DNA is unique to each individual, kind of like of fingerprint. The only people who share the exact same DNA code are identical twins.

Your DNA is actually 99 percent the same as all other humans, but that remaining one percent accounts for everything that makes you physically unique from other people and species. Where did this unique code come from? Your parents! DNA molecules are packaged into structures called chromosomes. Humans usually have 46 chromosomes total—23 that come from their mothers, and 23 that come from their fathers. Unless we are adopted, we tend to look a little bit like our parents because our DNA is made from copies of their DNA, which combine to make a new arrangement and code.

Even though life on Earth is incredibly diverse, we have much in common when it comes to DNA. For example, people have about 96 percent of the same DNA as chimpanzees, 90 percent the same as cats, and 85 percent the same as mice. About 50 percent of our DNA is the same as the DNA in bananas!

DNA, our genetic code, is what makes us both unique from and similar to all other living things. Want to learn more? You can explore the fascinating world of genetics and DNA through the Museum of Natural and Cultural History’s newest Explore from Home program, DNA—Cracking the Code! Available in English and Spanish, this fun family program includes hands-on experiments, crafts, and activities you can do at home. Head to mnch.uoregon.edu/explorefromhome to get in on the fun!

Visit the Museum of Natural and Cultural History’s website (mnch.uoregon.edu) for current hours and the latest lineup of virtual and online programs.