Evolution wouldn’t be possible without mutations. Why do genes mutate?

Genetic mutations involve a permanent reshuffling of a person’s genetic code. When that code is altered, it changes the way proteins do their job . Genes, or segments within our DNA, encode instructions for producing proteins vital to our survival. These proteins provide structure, function and regulation to our tissues and organs.

So what causes these mutations? Two things: errors during cell replication and environmental influences. Our cells continuously replicate their DNA to replace old or damaged cells. During this process, the double-stranded DNA separates, and each strand is copied to form a new double strand.

The most common mutation is when one “letter” in the code changes. Sometimes that letter, a base, is left out. Other times the mutation inserts a letter. In many instances, these changes don’t cause any problems, while other times the genetic muta tions can be life threatening or, at the very least, severely disabling. As of today, scientists have discovered more than 7,000 genetic disorders.

Genetic mutations involve a permanent reshuffling of a person’s genetic code.

Environmental factors play a significant role in inducing mutations. External physical agents, especially radiation, are powerful mutagens. Chemical agents introduce another dimension of external mutations. Some chemicals, known as base analogues, mimic nucleotides and can be mistakenly incorporated into DNA, leading to incorrect pairing in subsequent replication cycles. Biological agents, such as viruses, might integrate their DNA into a host's genome, leading to mutations too.

Genetic mutations are the instrument by which nature adds new variations to life. If the mutations give rise to advantageous traits, they get passed down through successive generations and can spread throughout the entire population of a species. Evolution just wouldn’t be possible without mutations springing up now and again to bestow new attributes on creatures.

Take humans, for example. About 12,000 years ago a single human had a mutation that granted them the incredible power to digest milk from a cow. Today this mutation is a common trait, saving millions of children worldwide who do not have an access to breastmilk.

Some research has shown that people with red hair have a higher tolerance for stinging pain and spicy food. It’s probably a good thing they can take the pain too, since the same gene mutation causes them to be less responsive to anesthetics that are injected under the skin.

Scientists believe people who feel totally energized on just four hours’ sleep have a specific genetic mutation.

Blue-eyed people probably have a single, common ancestor, who had a genetic mutation between 10,000 and 6,000 years ago.

Down syndrome is the most common chromosome abnormality, affecting 1 in 180 babies

Can we change our genes?

The human body is an amazing machine that does a multitude of things. It allows us to conceive, then build, spaceships that can travel to the distant reaches of the solar system. It allows us to smell a rose or to run a marathon. We can do these things, and so much more, because our bodies are made up of trillions of specialized cells that get their marching orders from DNA— our genes. Geneticists used to think humans were stuck with the genes that our parents gave us. We now know we can change them without changing our DNA sequence. This insight has given rise to a new science—epigenetics, which can be used to explain family constellations on a different level.

Alexandra Alexander