One of the greatest discoveries in the 20th century has been the role of DNA in the heritability and overall maintenance of life. One of the most controversial yet mind-blowing things that human beings have been able to accomplish is manipulating DNA and genetics for the sake of stem cell research, cloning or even choosing which characteristics that future children might have.
Each of a person's cells contains almost two meters (6.5 ft) of DNA coiled within it. The study of DNA is still ongoing, but some of the discoveries so far have been a bit weird.
The study of genetics and genomes are fascinating and have carried much significance for human health and the understanding of humans' own makeup. Those 46 chromosomes that everyone has can dictate what they look like, their intelligence, their talents and some might even argue their personality (depending on what side of the nature vs. nurture argument a person is on). This sophisticated development is a result of millions of years in evolution of living organisms.
To understand DNA, we must also look at human evolution as well. Here are 20+ most fascinating yet bizarre facts about human and animal genetics that most people probably didn't know about.
26 You Can Now Choose The Gender Of Your Child
Many people are shocked that such a technology exists at all to be able to choose whether your baby is a boy or a girl and others are shocked by the ethical implications of IVF (in virtro fertilization) procedure. Model, TV host and cookbook author Chrissy Teigen and her husband, musician John Legend publicly shared that she and her musician husband, John Legend, chose the gender of their baby, Luna Simone, during in vitro fertilization (IVF) which caused a mini scandal, according to parents.com.
In 2012, 61,000 babies were conceived via IVF, according to the Society for Assisted Reproductive Technology, which is just 1.5 percent of the 3.9 million births in the U.S. that year. Though not all clinics offer gender selection, the IVF was designed for parents who cannot conceive naturally.
25 When Two Sets Of Identical Twins Have Babies Their Children Are All Siblings (Genetically Speaking)
Having two sets of identical twins get together sounds like something out of a Mary Kate and Ashley movie, doesn't it?
Identical twins come from the same fertilized egg, which is why they are considered monozygotic. Since they both have the same DNA, they technically have the same moms and the same dads, biologically speaking. You will not find any cousins in the same gene pool whose genetics are closer to each other than those who come from the same sets of identical twins. This because they share 100% of the same DNA between their mothers and fathers.
24 Science Has Figured Out A Way To Create Three-Parent Babies
Science has now found a way to produce three-parent babies and it hasn't come into inception without controversy. The technique is to use DNA from three different people to create babies for women who are infertile. So far, no one knows whether or not children produced this way will be healthy or not. The process starts when an embryo scientist inserts a needle into a fertilized egg to extract DNA from a man and a woman who are trying to have a baby. The embryo scientist then transfers the DNA into a fertilized egg from an egg donor that has most of its DNA removed. So far, only Ukraine has legalized this practice but many women from other Westernized nations have flown to Ukraine to get this procedure done.
23 The Blue-Skinned Family In Kentucky
For nearly 200 years, the famous Fugate family in Kentucky have remained isolated from the rest of the world due to their rare and bizarre genetic condition. The Fugates have lived in the Appalachian Mountains for 197 years and have a history of producing children from a small gene pool.
Unbeknownst to them at first, members of this family possess a recessive gene that makes their skin turn blue. Though it is common knowledge not to marry and have children within your own bloodline, families who test the laws of nature see strange genetic defects.
22 Blue-Eyed People Have A Single, Common Ancestor With A Genetic Mutation
Most people had brown eyes until about 10,000 years ago when a single genetic mutation from the Black Sea switched the eyes from brown to blue. Approximately 8% of the world’s population now has blue eyes, according to Live Science.
According to Science Daily, new research shows that people with blue eyes have a single, common ancestor. A team at the University of Copenhagen have tracked down a genetic mutation which took place 6-10,000 years ago and is the cause of the eye color of all blue-eyed humans alive on the planet today.
Originally, all human beings had brown eyes. However, a genetic mutation called the OCA2 chromosome created a "switch" that literally turned off brown eyes. Variation in the color of the eyes from brown to green can all be explained by the amount of melanin in the iris, but blue-eyed individuals only have a small degree of variation in the amount of melanin in their eyes, according to the study.
21 Blonde Hair Is Not Exclusive To Europeans
When we think of blonde hair, we think of the fair skin and light eyes that often comes with it. Contrary to mainstream belief, blonde hair is not exclusive to those of white European descent. Natural blonde hair also occurs in native Melanesians and Aborgines from Australian tribes.
Originally, it was thought that these tribes originated from Eurasians, which was not the case. The New York Times confirmed this finding: "The Aborigines are thus direct descendants of the first modern humans to leave Africa, without any genetic mixture from other races so far as can be seen at present. Their dark skin reflects an African origin and a migration and residence in latitudes near the equator, unlike Europeans and Asians whose ancestors gained the paler skin necessary for living in northern latitudes."
20 Scientists Believe Red Hair And Pale Skin Was Evolutionarily Advantageous In Northern Europe
Red-heads, otherwise playfully known as gingers only take up two percent of the population, but they are even more unique than we may have originally thought. In a 2003 study at McGill University, red-heads have a higher pain threshold than blondes or brunettes. This is thanks to the rare genetic mutation associated with red hair and fair skin: MC1R. This same gene also means that they react to changes in temperature more intensely.
The MC1R gene also means that gingers don't need as much vitamin D as the rest of us. Evolutionary research has indicated that they can make it themselves in a more efficient manner.
19 Humans Have 98% Of Our DNA In Common With A Chimpanzee
The chimpanzee and another ape, the bonobo are human's closest living relatives. Humans, chimps and bonobos descended from a single ancestor species that lived six or seven million years ago, according to the American Museum of Natural History.
Though we share similar genes, we still look and behave differently than our mammal counterparts. For example, the human brain is larger and smarter than that of the chimpanzee and the bonobo. A gene's activity, or expression, can be turned up or down like the volume on a radio. So the same gene can be turned up high in humans, but very low in chimps. (amnh.org)
18 Elizabeth Taylor Had A Genetic Mutation Giving Her Double Eyelashes
Elizabeth Taylor is an iconic Hollywood movie star who is famous for her piercing purplish blue eyes and those stunning eyelashes. At first glance, one would assume that they are fake or that she has piled on the mascara. In fact, she had a genetic mutation medically known as distichiasis and it is a rare disorder.
Many eye specialists refer to this rare condition as an "accessory row" of eyelashes. What is most strange about this condition is that it can occur both at birth (like it did for Elizabeth Taylor) and at a later age in life.
17 Humans Are The Only Animals Capable Of Blushing
Blushing is an instance in humans that happens across all cultures of the world. Charles Darwin did a study on this explaining why we are the only species that have this capability when we run across certain intense emotions.
In his book, The Expression of the Emotions in Man and Animals he states: "blushing is not only involuntary; but the wish to restrain it, by leading to self-attention actually increases the tendency." Women and children are more likely to blush than men since they are socially conditioned to be modest and the expression of their emotions isn't as looked down upon.
16 Historically, Men Prefer An Hourglass Figure
The hourglass figure in women is something that men have been attracted to since the beginning of time. Hollywood glamorizes it and we see it everywhere on Instagram. Shapely hips in women are linked with fertility and overall health, according to Live Science.
An hourglass figure and a .70 waist to hip ratio is considered to be the most attractive shape for a woman across all cultures. It signifies health, fertility, and youth. This is because a small waist indicates that you haven't given birth yet and the wider hips indicate that you are ready to have children.
15 Women Tend To Prefer Men With A Large Jaw And Prominent Brow
In the same way that men are hardwired to seek certain physical characteristics from women, women seek out certain physical characteristics from men. Women at the fertile peak of their cycle favor more masculine faces, or at least less-feminine ones, than women not at the fertile peak or on the pill, according to Live Science. This is interesting because it depends on which time of the month a woman is one to tell whether she is open to a man with a feminine face.
There are some new interesting studies in evolutionary psychology that state more masculine men make great sperm donors but not necessarily awesome partners and fathers. The studies conclude that men with more masculine features tend to be less committed, less cooperative, more sensation-seeking in outlook.
14 Men Tend To Prefer Women With Smaller Chins And Less Prominent Brows
The opposite of a masculine face with a pronounced jawline and brow is an effeminate face with softer, more delicate features. Men are attracted to women with a smaller chin and less prominent brow, which signal higher estrogen levels, according to HuffPost.
Other facial features that signify feminine youthfulness is a shorter face, a small chin, thick lips and a smaller brow. The signals of youthfulness indicate a perceived potential for fertility, which is buried deep in our reptilian brains. These are also indicators of health and vitality, along with glowing skin.
13 Universally, A Symmetrical Face Is More Attractive Because It Signals Good Genes
It doesn't matter if you are a man or a woman, a symmetrical face is more attractive for either one of the genders. Some studies even reveal that those with the symmetrical face are healthier and live longer.
One theory posits that the trait is an advert of genetic quality or fertility, according to The Telegraph. Another alternative view is that preferences for a symmetrical face arose from cultural factors and say nothing about health, fecundity and other biological factors. Studies in the journal PLoS One by Dr. Anthony Little of the University of Stirling symmetric males had more masculine facial proportions and symmetric females had more feminine facial proportions.
12 Humans Have Very Little Hair Compared To Other Primates
Evolutionists would agree that human beings are practically bald compared to our other primate relatives. Some experts even venture to say that this factor might have allowed our species to thrive.
However, fur is beneficial: it insulates and protects the skin, and in some cases acts as a useful camouflage (BBC). Charles Darwin stated a theory that humans preferred hairless mates in the process of natural selection. Hence, we have become skin-exposed creatures.
Between 2-3 million years ago, our Neanderthal ancestors began to inhabit the savannah deserts, making it better for hairless beings to survive in the heat. This is another theory that explains why humans are hairless.
11 Goose Bumps Are A Remnant Of Thick Hair That Covered Early Humans
In all mammals in the animal kingdom, it is a natural reaction for the body hair to stand up when it gets cold. This way, it creates a fluffy layer of warmth. When we are cold, the muscles that surround our hair follicles contract, which is a natural reflex that is left over from when our ancestors had long body hair.
Since humans have evolved to have little to no body hair, when we have left is goosebumps where our old body fur used to be. This is why whenever we get shivers in the winter, we get all prickly in our skin.
10 Hybrid Vigor
It is common knowledge now that procreating between bloodlines is simply a bad idea. Crossing between the same genes has been linked to many genetic defects not only in animals but in human species.
Hybrid vigor, or heterosis, refers to the increased hardiness and improved function of the biological properties of a hybrid organism due to genetic diversity, according to wideopenpets.com.
According to the same theory, heterosis is the counterpart to what’s called “inbreeding depression,” which is when a lack of genetic diversity among breeding stock results in offspring with traits that hinder their overall fitness. This is the same reason why mutts are usually healthier and more intelligent than purebreds when it comes to dog breeds.
9 Some Women Can Have A Genetic Mutation That Makes Them Able To See 100 Million Colors
The human eye can see colors in different ways than others, hence why we have some individuals who are color blind. The human eye is packed with millions of cone-shaped cells that allow for color to be perceived, according to IFL Science.
Australian artist Concetta Antico is an individual who is considered to have the condition known as tetrachromacy, where around 12% of women have four cone cells instead of the regular three in their eyes. This allows them to see more colors that the regular human eye cannot see. This means that her eyes can enjoy a diversity of colors that is about 100 times greater than what is accessible to the rest of us, according to the Neurosphere.
8 Humans May Be Incapable Of Living Beyond 120 Years
Though modern technology and medical science have allowed the human population to live longer and longer, there may be still a limit to our capabilities as allowed by nature.
Experts last year claimed humans would “only” reach the ripe old age of 115 years – with a few managing to wait until they were 125 to pop their clogs, according to The Sun. In 1997, Jeanne Calment was the world’s oldest person, at the age of 122. Some studies reveal that since cell mutation will eventually happen no matter how healthy we are, there is even a limit to human life.
7 The Plagues In The Middle Ages Made 10% Of Europeans Resistant To HIV
From how far that medical science has come to treating HIV, there is a surprising fact that a certain percentage of people could be immune to the disease. Biologists at the University of Liverpool in a 2005 study have discovered how the plagues of the Middle Ages have made around 10% of Europeans resistant to HIV, according to eurekalert.org.
Many scientists believe that these individuals carry a genetic mutation that prevents the virus from entering the cells of the immune system. The highest levels of that gene are found in Scandinavia and the lowest levels are found in the Mediterranean.
6 Only 5-10% Of Cancers Are Due To Inherited Genetics
This will come as a shock but also somewhat of a relief to some. In fact, cancer is caused by how you take care of yourself and your environment more so than your genetic predisposition.
Sometimes, there are certain types of cancers that seem to run in families. According to the American Cancer Society, this might be because family members share certain behaviors or exposures that increase cancer risk, such as such as smoking. Cancer risk might also be affected by other factors, like obesity, that tend to run in some families.
Scientists have found that only 5-10% of cancers are strictly hereditary. The most common cancers caused by genes are including breast, ovarian, colorectal, and prostate cancer.
5 40-50% Of Human Genetic Information Has Not Been Classified In Any Other Animal Kingdom
Genetics is the study of inherited genetic variation. In the case of human genetics, it is a scientific study of inherited human variation.
Biologists have long been studying a form of "biological black matter" which in layman's terms means, our genomes also encode genes that produce long non-coding RNAs, whose functions are more mysterious. In other words, we don't exactly know how we are going to evolve in the future.
This could be a testament to the fact that humans are evolved mammals and our progression has yet to be determined.
4 There Is A Rare Condition That Protects Against Cancer And Diabetes
It turns out, being born a dwarf is not as bad as you might think it to be. In fact, there is a rare form of dwarfism that may be able to protect against cancer and other fatal diseases.
The condition is called Laron syndrome which is a rare form of dwarfism that has some genetic benefits for those who have it. It is caused by a genetic mutation that prevents the body from responding to growth hormone, according to Discover Magazine.
Though it stunts the growth and development of the physical stature, it also stunts the growth of mutated cells in the body.
3 Cilantro Tastes Like Soap For 4-14% Of The Population
When people say that they hate cilantro, it is not that they are intentionally trying to be picky eaters. Instead, there is a gene that causes the taste buds to taste cilantro in a completely different way.
For 4-14% of the population, cilantro tastes like soap rather than the refreshing herb that everyone knows and loves. After conducting a few separate studies, scientists were able to pin down most cilantro haters as people with a shared group of olfactory-receptor genes, called OR6A2, that pick up on the smell of aldehyde chemicals (Huffington Post).
2 Sickle Cell Anemia Protects Against Malaria
Sickle cell anemia is a condition that causes the red blood cells to be misshapen and break down. Sickle cell anemia happens if they inherit two faulty copies of the gene for the oxygen-carrying protein haemoglobin, according to New Scientist. This is an inherited blood disorder that is common in 8-10% of African Americans.
There have been recent studies that indicate this faulty gene carries resistance to malaria for those who are infected with sickle cell anemia. Though malaria is caused when bitten by an animal, the gene prevents the disease from taking ahold after the individual has been infected.
1 We Still Don't Know The Function Of More Than 80% Of Our DNA
After about 20 years of studying DNA, many biologists have concluded that about 80% of our DNA is utterly useless. After arguing that most of the human genome must have some kind of function, it turns out that sometimes there needs to be some grey matter to give the important genes a purpose.
According to New Scientist, by the 1970s, it was becoming clear that only a tiny proportion of a genome encodes functional proteins – about 1 percent in the case of us humans. One has to wonder why this extra stuff has to exist though.
References: Kick Facts, Listverse, Fact Retriever, Thought Co., Huffington Post, List 25, parents.com, Science Daily, New York Times, American Museum of Natural History, brocku.ca, Live Science, Live Science, Huffington Post, The Telegraph, The Neurosphere, NY Post, Discover Magazine, Huffington Post, New Scientist