DNA: The Building Blocks of Life

When you first look at your DNA results, you might be surprised, particularly if you compare your results to a sibling. After all, if the two of you have the same parents, then your DNA should be pretty close. Right?

You probably already know that you inherit half of your DNA from your father and half from your mother.

But your DNA carries so much information that there can be a lot of variation in what gets passed on.
Why don’t we look at it a different way?

Let’s use names and letters as a metaphor for the DNA that family members share.

Imagine someone whose DNA “name” is ANDREW.

A N D R E W

But when he and his wife, SANDRA, have children, he can only pass on half of that name to each child. In one son’s case, we’ll say that he passes on the D, the E, and the W.

SANDRA passes on the letters A, D, and R, and those six letters combine to give their son the genetic “name” EDWARD.

A N D R E W
S A N D R A
E D W A R D

Meanwhile, another couple, GRAHAM and ELAINE, have a daughter named ANGELA. She inherited the G and two As in her name from her father and the E, L, and N from her mother.

G R A H A M
E L A I N E
A N G E L A

You still with me? Alright, let’s take it a step further.

Let’s say a few years down the line, EDWARD and ANGELA get married and have kids of their own. Their DNA mixes to produce three children.

E D W A R D
A N G E L A
G E R A L D
R E A G A N
G L E N D A

What’s interesting, though, is that even though all three of these children have the same two parents and the same four grandparents, the DNA they inherited is distinct.

Some information shows up in every grandchild…

…but other pieces are nowhere to be found.

A N D R E W
S A N D R A
G R A H A M
E L A I N E
E D W A R D
A N G E L A
G E R A L D
R E A G A N
G L E N D A

Of course, actual DNA is much more complex than this example. Here, we’re just looking at six-letter names, while the DNA we look at to make up your "genetic name" has hundreds of thousands of letters.

G E R A L D
R E A G A N
G L E N D A

That’s why testing lots of people in your family can be helpful. Your father’s results might show an ethnicity that yours didn’t. Your sister’s results might connect you to even more cousins.

Father

4% Native American

Sister

Cousin Match Peter Atherton 5th-8th cousin +134 more

Your sister’s results might connect you to even more cousins.

By looking at your DNA results alongside your family’s, you can achieve a more complete view of your genetic history.

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