Being eaten is bad.  You want to avoid it.  You are one giraffe in a group, out in the open fields, lions are prowling around you at all times.  Your ear twitches at the slightest of snaps in the brush, and you lift your great long neck and search the area.  It was just the wind this time.  The lions will come at some point though.  They need to eat.  So what will decide which one of you will be eaten?  Whoever is in the wrong place at the wrong time?  Whoever runs the slowest?  Those will play a part.  But remember, the lions have to see you first.

There are many parts of you that help you survive.  Without that long neck, you would not be able to reach the delicious leaves high up in the trees.  Without those horns on the top of your head, you would not be able to swing your neck like a whip and hit other giraffes when they get too close.  All these things on the outside of your body are important, but it's what's inside that makes you that way.  Genes are the directions a living thing gets from its parents and passes on to its children.  They make living things look and act the way they do.  Long necks and horns are great things to have, but the things that help you stay away from lions are your spots.  You got those from your parents and you'll give them to your children.

With these spots, I blend right in with the trees.

Giraffe spots are as different from each other as people's fingerprints.  These spots may be easy for a person to see at the zoo, when the giraffe is standing in front of a gray wall.  But in the wild, the spots look like nothing more than shadows to a lion's eye.  How did you and other giraffes get these spots that keep you safe?  One way it might have happened is through changes in the directions that were used to make you.  A mutation is a change in a gene that can make a living thing look or work differently than its parents, or it can do nothing to change the person.  

Most of the time, these changes do not do anything to the living thing.  One gene changes and the children turn out the same as their parents.  Sometimes, they can lead to a change and this is where things get interesting.  Children could end up with spots or longer necks and they might live longer because they were harder to hunt and were able to reach more leaves for food.  It won't happen all at once, but baby giraffes could be born with necks that were a little longer and a little longer, for millions of years, until they were as long as your giraffe neck is now. 

These changes can be a good thing if it gives a living thing spots that confuse animals that want to eat it.  It could also be good if it gives them a neck that can reach more leaves in a tree.  It can be a bad thing if it gives the animal spots that look like bright red lights to a lion.  All of these are examples of changes in the traits of a living thing.  A trait is a part of a living thing that they get from their genes.  The color of your skin is a trait.  How tall you are is also a trait.  You do not get to decide what these will be.  Your parents gave you these traits and you'll pass yours on to your children.

Mom, when I grow up I want to look just like you.

The directions you got from your parents are only there because they lived and were able to have children.  If you live, you will be able to pass yours on to your children.  Your genes make you the way you are and they do this because they hold the directions for very tiny things inside your cells.  Proteins are molecules made from genes that are used to build everything in living things from how their body is built to how it will work.  You eat them in your food, your body breaks them down, and uses to build you.  It is these and nothing else that make giraffes tall, small, spotted, or one color.  This way you look might change whether or not the lion will see you or the giraffe next to you first.

Wait! Those aren't giraffes, just a bunch of moving shadows.

Being eaten is bad.  But as a giraffe, it will not be up to you who gets eaten and who does not.  From your parents, you get genes, directions that make you look and act the way you do.  Changes in your genes, called mutations, can make survival more, less, or just as likely by making you look different than those around you.  All of these come from proteins made from your genes.  The good news is you can now just eat leaves and not have to worry about if the lions see you or not.  Your spots have already decided.