When you first start the game, or when your life form has reached the end of its life, you will have an option to enter the DNA Editor. The DNA Editor is a three-in-one tool. It has a list of DNA components. It has a visualization of your developed life form. It also has a listing of helpful DNA upgrades.
In visualization mode, you will be able to move body parts around. You will have access to every detail of the creature you are developing. You can move bones, organs, skin, etc. When you select a part, you will get the option to edit that part's DNA to change how it works. For instance, real bone has marrow that produces blood cells, but you could make any part of your creature do that just by moving DNA around.
If you choose the option to edit the DNA of the part, a new window will appear with all of the details of that part. Each component of the part is a gene that affects that part, but genes can affect multiple parts. You can choose to switch on and off certain genes, or switch it for just the part you are interested in. When you leave genes in your species, the other creatures of that species may switch the genes on or off. Some genes can be switched during the life of a creature, for adaptation, while other genes can only be switched in their offspring. There are two basic ways that genes may affect creatures. They may affect their bodies, or they may affect their behavior.
How your creature acts is very important to its survival. There are many special genes that are made just for deciding how it will walk, how loud it will speak, or what its fears and desires are. When you play the first creature in your species, its behaviors are changed by how you make it behave. The system will study your every move, and make genes that teach other creatures of that species how to act.
The most popular and best understood genes are for physical traits. They decide how your creature grows and changes over time. They make your creature grow claws or a beak, or even scales. They tell your creature how big it is going to be, and what food it can digest. The system will study what you make your creature eat, and give it genes to digest it. It will also help decide how big its muscles are, and how much food your creature needs to eat survive its lifestyle.
When your creature encounters things in its environment, it remembers the hardships. It remembers the composition of the air or water, and it gathers helpful DNA traits from the main library. If you make your creature jump high, but not have strong bones, it will give you DNA for stronger bones. If your creature spends a lot of time in the water, it may request DNA that gives its skin an adaptation to water. It will always look in your current DNA storage so that you will not always have to purchase DNA with points, but if it can't find it there, you will have to purchase the DNA in the list. You can manually help your species to adapt using the Element Sampler
If you become very interested in the functions of DNA, you may wish to make some features of your own. Since this game is based on science, you can use knowledge of biology to make completely original creatures. If your creature is original enough, your name is added to the authors list. If you invent a new gene, you get to name it, and you become the author of it (or co-author if you were the first to request it from a developer/mod).
Making new genes is not easy, but it is not too difficult. It involves looking through the DNA library of all of the functions that you have stored. You can also review samples of biological material from your previous life that you stored in the environment database. If you are using an observed trait, the system will make a prototype model of the DNA that will be unique and very primitive. If you used the library, you will be getting exactly what you wanted.