Mutations

0:00 what do you think of when you first hear the word mutant do you immediately imagine cool supernatural powers? Sure, these powers might make people mutants in comic books. But, did you know that in our world we are all mutants? So, what do we mean when we say the word mutant? And what is a mutation? To answer this question, we need to go back to the beginning of human life: the union of egg and sperm cells. Since both egg and sperm cells contain DNA we inherit half of our own DNA from each parent. All of the DNA in a single person's body is called their genome, and to find out how unique we really are, we have to compare our genomes to our parents' genome. DNA is basically a set

0:47 of instructions that our cells use to build proteins, which act like the cogs and wheels within cells. Proteins influence the way our bodies appear, function, and respond to our environment. The DNA instructions for building proteins are spelled out using four molecules called nucleotides: A, C, T and G for short. These nucleotides are the key to mutations. To be exact, a mutation is a change in nucleotides, and it automatically translates to a change in the protein product. Think of it like a blueprint: when you change the instructions, the final design will change accordingly. most mutations occur during cell division, when a mother cell fully duplicates its DNA so that each of its daughter cells can receive a copy.

1:34 Occasionally, mistakes can occur and one copy of DNA that gets passed down might be slightly different from the others. The DNA that contains the error is called the mutated DNA. DNA mutations can occur in two different ways. Somatic mutations occur in a person's cells during their lifetime and do not get passed down to future offspring. For example, smoking can cause somatic mutations which lead to cancer and lung diseases. Hereditary mutations, on the other hand, are locked into your genes from the moment you're born. That's because they occur in a sperm or egg cell of your parent before or shortly after they fuse into an embryo, the first cell that makes you. Hereditary mutations are transmitted to you and your children, because your embryo becomes the template for all of your

2:22 cell development. When a hereditary mutation happens for the first time in your embryo it's called de novo, which means "new" because it didn't exist in your parents. A recent study estimates that every one of us is born with about 60 do novo mutations. On the other hand, you may inherit old hereditary mutations from your ancestors. Both old and new hereditary mutations will be passed down to future generations, each adding to the genetic variation within a population. Genetic variation consists of the unique family traits or characteristics of a certain population within a certain geographical region and it's the reason we're not exactly the same as our relatives. There is no one else in this whole world who has the exact same genome is yours. All thanks to mutations! Most hereditary mutations are

3:12 neutral--as far as we can tell, they have no observable impact on health or outer appearance. Mutations are an inherent part of life. So, why do we need them? If mutations did not occur, we wouldn't have any new genetic variation. After a while, everyone would be made up of a singular, dominant genome. This would be fine as long as our environment stays the same. But our environment is fickle, and nature selects which random mutations help us survive as the world changes around us. This is how evolution works, and it depends on the genetic variation provided by mutations. Without genetic variation, we wouldn't be able to adapt to environmental changes. So, our mutations don't necessarily give us cool superpowers, but now you know they give us the power to survive!