82 Interesting DNA Facts

By James Israelsen, Associate Writer

Published June 27, 2020

DNA is a molecule that has a variety of functions within a living organism, including telling the organism how to “look,” facilitating reproduction, and helping cells to make proteins._[23]
A single strand of DNA is thousands of times thinner than a single strand of human hair._[23]
Each strand of DNA contains 3 building blocks: a group of sugars, a group of phosphates, and a nitrogen base._[23]
DNA is built like a twisting ladder, with sugars and phosphates forming the side rails and various chemical bases forming pairs of rungs._[23]
The specific sequence of chemicals in a strand of DNA tells the organism what form it should take, so every type of organism has their own unique chemical pattern in their DNA._[23]
Of the 3 million chemical bases within a piece of human DNA, 99% are the same for every human being; only 1% of our DNA is responsible for the vast varieties of physical traits a person may exhibit._[23]
There is DNA inside the nucleus of every single cell in an organism._[23]
Whenever a cell containing DNA divides, the DNA makes an exact copy of itself so that every cell in an organism always contains the same blueprint._[23]
Scientists have recently suggested that as many as 145 of the genes in the human genome may have actually “jumped” into our DNA from non-animal organisms such as bacteria and viruses._[22]

Franklin's contributions to the discovery of the double helix were not fully recognized until after her death

The double-helix structure of DNA was first discovered by scientists Watson and Crick in 1953. Rosalind Franklin, a chemist, also played a large role in the discovery, one only recently recognized._[23]
Although most of the genetic information in DNA is passed on from parents to offspring, some simple organisms, such as bacteria, can also share genetic information with their neighbors through a phenomenon called “horizontal gene transfer.”_[22]
Horizontal gene transfer, a phenomenon in which simple organisms share genetic information with their near neighbors, is what allows bacteria to respond so quickly to antibiotics, sometimes making certain kinds of infections immune to treatments that previously worked._[22]
Despite the fact that it is a much more simple organism, an amoeba has 200 times more DNA than a human being._[21]
Because they have virtually the same DNA, identical twins have been widely studied in attempts to understand which human traits are a result of nature and which ones come from environment and upbringing._[15]
A strand of DNA replicates itself by separating into 2 identical strands, each of which will then make a copy of itself. Each one of the old strands will pair with one new strand to create a new DNA molecule._[5]
All organisms contain some amount of “junk DNA” (DNA that is not used for anything), but they discard it at different rates: fruit flies get rid of it almost immediately by not passing it on to their offspring, while onions hang on to so much junk DNA that their genome is several times the size of a human being’s._[21]
DNA is an abbreviation for deoxyribonucleic acid._[5]

DNA evidence has proven of immense forensic value

The 1986 rape and murder of 15-year-old Dawn Ashworth was the first crime to be solved by DNA evidence. Serial killer Colin Pitchfork was identified after another man admitted to having provided a DNA sample on his behalf._[3]
A gene is a segment of DNA that contains the information for how to make the proteins that result in a specific trait._[5]
Use of DNA evidence in criminal cases has become standard practice, but there are a number of unsolved cases involving identical twins. In such cases, police have been unable to identify which of the twins was the perpetrator._[8]
A case study of genetic twins in which only one twin has been diagnosed with severe symptoms of autism has suggested that although autism may be hereditary, its severity may be the result of environmental factors._[15]
Although DNA is responsible for determining a wide variety of human traits, many scientists think that there is a secondary factor, called epigenetics, that determines when and how strongly these traits are manifested._[15]
DNA alone does not determine whether someone is at risk for developing alcohol use disorder. However, there are genes that either increase or decrease someone’s likelihood of addiction._[7]
Some people of Asian descent carry a unique gene that alters the rate of alcohol metabolism in a such a way that the experience of drinking is always unpleasant—thereby reducing the likelihood that its carriers will develop alcoholism._[7]
Geneticists believe that the same segment of DNA in the human genome is responsible for the development of both schizophrenia and bipolar disorder._[4]
Three percent of the funding for the Human Genome Project, which sought to map out the entire sequence of human DNA, was dedicated to investigating the legal, ethical, and social implications of genetic science._[13]

Miescher was the first person to isolate nucleic acid

Although DNA was first discovered in 1869, by Swedish chemist Friedrich Miescher, it wasn’t until 1943 that scientists were able to demonstrate the role it plays in passing genes from parent to child._[5]
The Human Genome Project waited until April 25, 2003, to announce the successful conclusion of their project so that the date would coincide with the 50th anniversary of the discovery of the double-helix structure of DNA._[13]
Due to its size and complexity, the DNA of human beings is believed to have evolved much further than that of any other organism._[13]
At the time of the 9/11 attacks, New York City’s disaster protocols failed to foresee the need for a forensics team responsible for using DNA to identify such a massive number of victims. As a result, some families had to wait many months before receiving confirmation that the remains of their loved ones had been found._[16]
Although a person’s mitochondrial DNA is an exact copy of their mother’s, two totally unrelated people can have mitochondrial DNA so similar that geneticists prefer not to use it for identification._[16]
The average time for a forensics response team to identify the victims of a mass attack or accident by using DNA is around 3 months. As a result of the 9/11 attacks, however, the state of New York was later prepared to identify all 265 passengers of a crashed American Airlines flight within a month of its occurrence._[16]
Eye color was shown to be a trait inherited through sex chromosomes when a lab tracked generations of fruit flies with white eyes, a feature only possessed by male flies._[6]
There are two kinds of DNA in a human body: nuclear DNA comes from both the father and the mother, while mitochondrial DNA is inherited solely from the mother._[16]
Identical twins have the same genetic code, whereas fraternal twins only share around half of the same DNA._[15]

The similarities are more than skin deep

An identical twin who has a criminal co-twin is over 1.5 times more likely to commit a crime than a fraternal twin with a criminal sibling._[15]
Studies comparing identical twins separated at birth—twins who share the same genetic code but were raised by different people—have suggested that a person’s IQ is largely a result of heredity rather than environment._[15]
Human DNA samples can be collected from different sources, including blood, hair roots, and saliva._[16]
Scientists such as Gregor Mendel and Charles Darwin began hypothesizing about the existence of genes in the mid-1800s._[6]
Early names suggested by 19th century scientists for genes included “elementen” and “gemmules.”_[6]
Until recently, DNA was believed to be entirely responsible for the traits that an organism inherits. However, it has been discovered that environmental changes to proteins involved in activating certain genes can also be inherited._[19]
One of the first cold cases to be solved using DNA evidence was the 1978 murder of Deana Bowdoin by Wayne Dixon, solved almost 20 years after it occurred._[11]
DNA evidence has been used to identify kidnapped infants, such as when Gloria William kidnapped a baby only a few hours after her birth and raised her for nearly 10 years as her own._[11]
As the result of a failed experiment, British geneticist Alec Jeffreys accidentally discovered a method for using DNA to identify family relationships and unknown individuals._[3]

Because of the relative simplicity of their genetic structure, fruit flies were ideal early test subjects

Because they breed so quickly and only possess four chromosomes, fruit flies were the most commonly used specimen by geneticists in the early 20th century._[6]
The first time DNA was used to find a criminal, over 5,000 men living in the area where the crime occurred—all men over the age of 16, with only one exception—complied with police requests for DNA samples._[3]
Since the discovery of a method for using DNA to identify criminals, around 50 million people have either provided or been compelled to provide DNA samples in criminal investigations._[3]
The word “clone,” the process of using DNA from one specimen to create an identical organism, was first coined by biologist J.B.S. Haldane in 1963._[9]
The first animal ever cloned, the famous Dolly the Sheep, was named for singer-songwriter Dolly Parton._[9]
The first dog to be cloned was born in South Korea and named “Snuppy.”_[9]
Single-celled organisms, some plants, and identical twins are all considered to be “natural clones” because they come from genetically identical “copies” of the same DNA._[2]
Animals that have been cloned include mice, sheep, dogs, cats, deer, horses, mules, oxen, rabbits, rhesus monkeys, and rats._[2]
There are three different types of cloning: gene, reproductive, and therapeutic. All types use DNA to create copies but in different ways._[2]
The Human Genome Project was a joint effort by scientists from several nations to map the entire human blueprint contained within human DNA._[18]

Each human has between 20,000 and 25,000 genes

In reproductive cloning, DNA from the mature cell of an animal is placed into an egg that has already had its own DNA removed._[2]
Two different groups of South Korean scientists claim to have succeeded in creating a cloned human embryo, one in 1998 and one in 2004. However, there is no evidence that either claim is true._[2]
Clonaid, an organization that asserts that humans were originally created by extraterrestrials, claimed in 2002 that it had succeeded in cloning a human girl they named Eve. They later announced the successful creation of 12 other clones, but none of these clones have ever been confirmed to exist._[2]
Due to the nature of cell division in humans and other primates, cloning would involve technical difficulties that make it much more unlikely to happen._[2]
Although they share the same genetic material, cloned animals do not always look identical, demonstrating that environment and other factors also play a role in how an individual turns out._[2]
CC, the first cat to be cloned, does not look like the cat from whom she received her genetic material; the cats are both female but have very different coat patterns and colors._[2]

Dolly was cloned by scientists at the University of Edinburgh's Roslin Institute

Dolly the Sheep was the only clone of a group of 277 embryos to be born alive._[2]
The Scottish researchers who cloned Dolly the Sheep have also cloned sheep genetically modified to produce milk that contains a protein essential for blood clotting. They hope to use their research to find solutions for humans whose blood does not clot._[2]
Advocates of reproductive cloning, in which whole animals are copied, say that the creation of identical mammals would be useful in drug tests and trials, where the response of the animals to a given drug would be the same for every animal, thus eliminating unknown variables._[2]
The FDA declared in 2008 that the meat and milk from cloned animals is as safe as that from natural ones._[2]
The first clone of an endangered species, an Asian ox called a guar, was born in 2001. The guar died just a few days after birth._[2]
Researchers have confirmed that cloned animals suffer from certain health defects, including flaws in vital organs, premature aging, and immune system problems._[2]
Dolly the Sheep, one of the most famous animal clones, died at half the average age for a sheep because she inherited the already-aged cells of her donor parents._[2]
Thomas Hunt Morgan, a scientist at Columbia University in the early days of the development of genetics, conducted his research in a room that was known as “the Fly Room,” due to his cultivation of fruit flies for use in research. Some of his best students who helped with his research eventually came to be called “the Fly Boys.”_[1]
A Canadian dentist paid $30,000 for one of musician John Lennon's teeth. The dentist hopes to extract some of the former Beatles' DNA in order to clone him. If successful, the dentist has said he intends to raise the clone as his own son, buy him a guitar, and try to help him avoid drugs and alcohol._[14]

Mendel's pioneering work focused on analyzing pea plants

Although Gregor Mendel, who originally conducted his experiments with pea plants over 150 years ago, is now famous as the father of modern genetics, his work was quickly forgotten after his death, only to be rediscovered in the 20th century._[1]
DNA has a half-life of around 521 years. This means that many ancient species can never be cloned back to life, even if samples of their DNA can be recovered from fossils._[10]
Blockbuster movie Jurassic Park shows scientists extracting DNA from dinosaur blood preserved in amber in order to clone them. Scientists have proven that, due to the rate at which DNA degrades, this is likely impossible to ever happen._[10]
Rather than create clones, scientists who are currently working on bringing the woolly mammoth back from extinction are using elephant DNA, which they instead modify for certain traits to create a mammoth._[17]
Some pigeons in Australia have had their DNA “edited” so that they carry some genetic traits from the now-extinct passenger pigeon._[12]
“CRISPR” is a technology that allows scientists to “edit” the DNA of existing animal species and has been used to incorporate traits from extinct species into existing ones._[12]
DNA that has been extracted from the bones and other remains of extinct species can be used to sequence the genes of these species, making it possible to bring about their “de-extinction.”_[12]
Some opponents of using fossilized DNA to bring back animals from extinction argue that it is a pointless expense when we don’t fully understand why the animal went extinct in the first place and haven’t changed the environment that caused the original extinction._[12]
Every cell in an organism contains two copies of every gene._[20]
If an individual inherits a widow’s peak gene from both parents, or one from one parent but not the other, that person will have a widow’s peak._[20]
About 70% of people with European ancestry can roll their tongues, an ability that likely comes from having the same gene in their DNA._[20]
Cleft chins and dimples are the result of the presence of genes that carry these traits in at least one parent’s DNA._[20]
The ability to taste the bitter chemical PTC in certain vegetables is a trait inherited through DNA._[20]