Epigenetics—Inheriting More Than Genes

You’re probably familiar with the phrase, “You are what you eat.” But did you
know that you are also what your mother and grandmother ate? The budding science
of epigenetics shows that our physical makeup is about much more than inheriting
our mother’s eyes or our father’s smile.

We are accustomed to thinking that the only thing we inherit from our parents
is genes—packets of information in DNA that give instructions for proteins.
These genes determine our physical traits such as hair and eye color, height,
and even susceptibility to disease.

But we also inherit specific “modifications” of our DNA in the form of chemical
tags. These influence how the genes express our physical traits. The chemical
tags are referred to as “epigenetic” markers because they exist outside of (epi-)
the actual sequence of DNA (-genetics).

Let me use an analogy to explain. The following sentence can have two very
different meanings, depending on the punctuation used. “A woman, without her
man, is nothing” or “A woman: Without her, man is nothing.” Perhaps it’s a silly
illustration, but it gets the point across.

The words of both sentences are the same, but the meaning is different because
of the punctuation. The same is true for DNA and its chemical tags. The sequence
of DNA can be identical but produce different results based on the presence
or absence of epigenetic markers. For example, identical twins have the same
DNA sequence but can have different chemical tags leading one to be susceptible
to certain diseases but not the other.

Parents can pass down epigenetic markers for many generations, or their effect
can be short-lived, lasting only to the next generation. Either way, the changes
are temporary because they do not alter the sequence of DNA, just the way DNA
is expressed.

Your behavior could change how your body expresses
its DNA. Then those changes could be passed to your children.

What does this mean in practice? Your behavior, including the food you eat,
could change how your body expresses its DNA. Then those changes—for good or
bad—could be passed to your children! If you do something to increase your susceptibility
to obesity, cancer, or diabetes, your children could inherit that from you.

In one experiment, mice from the same family, which were obese because of
their genetic makeup, were fed two different diets. One diet consisted of regular
food. The other diet consisted of the same food but contained supplements that
were known to alter the chemical tags on DNA.

Normally when these mice eat regular food, they produce fat offspring. However,
the mice that ate the same food with the supplements produced offspring that
were normal weight. The parents’ diet affected their offspring’s weight!

Scientists are still trying to understand the details. The epigenetic markers
that were modified by the food supplements appear to have “silenced” genes that
encourage appetite. The parents’ environment—in this case, the food they ate
before becoming parents—affected the weight of their offspring.

Certain types of medicine have also been suspected of causing changes in epigenetic
markers, leading to cancer in the offspring of women who took the medicine.
For example, a type of synthetic estrogen prescribed to prevent miscarriages
has been linked to an increased number of cancers in their daughters’ and granddaughters’
reproductive organs.

Studies point to changes in the epigenetic markers related to the development
of reproductive organs, which the mothers passed down to their daughters. This
finding affirms the adage that “you are what your mother—or grandmother—ate.”

Epigenetics: A Problem for Evolution?

Until these findings, many evolutionists dismissed the ideas of Charles Darwin’s
contemporary, Jean-Baptiste Lamarck, who believed that animals could acquire
new traits through interactions with their environment and then pass them to
the next generation. For instance, he believed giraffes stretching their necks
to reach leaves on trees in one generation would cause giraffes in the next
generation to have longer necks. Many science textbooks today reject Lamarck’s
ideas, but epigenetics is a form of Lamarckianism.

Of course this is contrary to classic Darwinian evolution. The theory of evolution
is based on random changes or mutations occurring in DNA. If a change happens
to be beneficial, then the organism will survive via natural selection and pass
this trait to its descendants.

Although evolutionists do not deny the reality of epigenetics, its existence
is hard to explain! Epigenetic changes are not random; they occur in response
to the environment via complex mechanisms already in place to foster these changes.

These non-random epigenetic changes imply that evolution has a “mind.” Creatures
appear to have complex mechanisms to make epigenetic changes that allow them
to adapt to future environmental challenges. But where did this forward-thinking
design come from? Evolution is mindless; it cannot see the future. So how could
it evolve mechanisms to prepare for the future?

But God does! God is omniscient (all-knowing), and He foreknew Adam and Eve
would sin. He would judge that sin (Genesis 3) and the world would be cursed
(Romans 8:22). God knew that organisms would need the ability to adapt in a
world that was no longer “very good.” God likely designed organisms with epigenetic
mechanisms to allow them to change easily and quickly in relation to their environment.
These types of changes are much more valuable than random mutation and natural
selection because they can produce immediate benefits for offspring without
harming the basic information in the actual sequence of DNA.

Although we often hear that “nothing in biology makes sense except in the light
of evolution,” it should be said that “nothing in biology makes sense without
the Creator God.” Epigenetics is an exciting field of science that displays
the intelligence and providence of God to help organisms adapt and survive in
a fallen world.

Tagalongs to Our Genetic Code

Our DNA includes additional components, which may sometimes be passed from
parent to child at the same time as the genetic code. First are molecules
attached to the DNA, called methylation marks, that turn genes on and off.
Second are balls of proteins composed of histones, which the DNA wraps around.
Histones and a portion of these proteins, called histone tails, regulate how
the DNA is folded (and thus what is turned on or off).

The food you eat and other aspects of your environment can change these
tagalongs. Then they can be passed down to your children and even your grandchildren,
affecting the genes that are turned on.

SourceThis article originally appeared on answersingenesis.org

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