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
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.
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
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
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!