Seven fascinating facts about DNA: family history and DNA

Find out how DNA could enhance your family history research, with Abby Drexler's seven fascinating DNA facts.

DNA (deoxyribonucleic acid) is your body’s blueprint. All living creatures possess DNA; the self-replicating material that makes up chromosomes and carries every last bit of our genetic present and past. Your DNA is the "Story of You" AND all of your ancestors; a story that is exclusive to you.

What can a DNA test tell you about your family's story?

DNA testing can lay your genetic story out to be read and understood, allowing you to take in the bigger picture of your ancestral heritage. Information which once taken in can illuminate family trees for anyone looking to shore up old family disputes; data which is capable of clearing the name of an innocent man or woman who could otherwise serve a life sentence for a crime he or she never committed.

DNA testing can bring your life new and unexpected meaning. It's simple, safe and non-invasive, and modern labs can retrieve complete ancestral blueprints from your:

*Hair
*Saliva
*Blood
*Semen
*Skin Cells
*Fingerprints

You can use the results of your genetic testing to complete your family tree or to plan out an international trip to explore all the places your ancestors once lived. 

1. You have a HUGE amount of DNA
Human DNA is almost infinite. It would take more than 200 books with 1,000 pages in each book, to hold all of your DNA. That's the equivalent of 3 gigabytes of data, and if we could stretch it out and touch it end to end, it would wrap around the earth and sun more than 600 times!

2. DNA is fragile
Although DNA self-replicates every second and hosts variable ways to repair itself, it isn't infallible. Your DNA can be injured throughout the day by various things including UV light, pollutants, toxins, and radiation. As you age, your DNA can experience multiple errors during transcription, and failures to repair itself; resulting in genetic mutations which are responsible for creating diseases, illnesses, and different states of disrepair in our bodies. You might recognize some of these mutations by their more common names;
*Cancer
*Influenza
*Common Cold
*Parkinson's Disease
*Alzheimer's/Dementia
*Rheumatoid Arthritis

Scientists are currently working on new technology that they've named CRISPR, which is being designed to allow them to "edit" genomes. They hope that they will be able to "reprogramme" DNA to repair itself and bring cures to most of the world’s most horrific diseases and disorders.

3. Not all testing labs are equal
Not all testing facilities are going to provide you with accurate, reliable or thorough information. There are many DNA testing scams also. To avoid scams and low-quality testing labs, make sure you seek out a testing provider that has some form of accreditation.

4. "Looks" mean little
A common myth exists which suggests that in order to be related, we must look like one another. It's believed that if a child doesn't look like their mother, father or another recognizable relative, then they must not be the child of both parents. 

The truth is: looks mean little. Our DNA is vast from millennia of evolution. A person can be born with the looks, build, and attitudes of distant ancestors. Our physical appearance is determined by infinite genetic combinations and reactions that begin occurring at conception, and continue to change as we age. It's much more common that we will look like one or a combination of both parents, though that is not a requirement with DNA.

Interestingly enough, DNA physical combination similarities exist often enough that you can have enough in common with a total stranger regarding physical looks, that most everyone would assume you were identical twins. This phenomenon has fueled a trend of seeking out non-related "twins".

5. Deep DNA data 
DNA testing has become especially in depth and continues to evolve with increasing public interest in genetic testing for ancestry, paternity, and criminal justice. The more people who submit DNA for testing, the more detailed the library of genetic markers becomes, allowing for more significant connections and data. DNA testing is so thorough now that in some tests you can see if you had any Neanderthal ancestors and if any of your ancestors migrated from their geographic origin.

6. Solo-twinning
Most twins are never born. Instead, they are reabsorbed by the womb or by the first twin before they ever develop into a fetus. In most cases, their DNA is also absorbed; effectively deleting the person who would've evolved from that DNA blueprint. It is possible, although rare, for the primary twin to host and carry two different sets of DNA from an absorbed twin.

7. Radioactive DNA 
Because of all the nuclear testing and posturing going on during the Cold War between the US and Russia, everyone born in 1955 or after, has some trace amounts of radioactive carbons in their DNA, which they have passed on to their descendants, who will pass it on to all of theirs. There are currently no concrete ways to test how this affects our evolution, though many researchers are sure that it has and are working to find ways to prove it.

Abby Drexler is a contributing writer and media specialist for Genetics Digest. She regularly produces content for a variety of science and education blogs about the wonders of genetics and DNA.

(image copyright School of Natural Resources, Ann Arbor)