Facts About Genetics That Most People Are Clueless About

Genetic testing is so commonplace today that home kits are available from multiple commercial labs.

It's hard to imagine it was less than 40 years ago that forensic scientists were finally able to get DNA evidence accepted in court.

But just because we're familiar with genetic testing, that doesn't mean we're all experts.

Reddit user Lysolmao asked:

"What is a genetics fact that not a lot of people know?"

TP53

"There is a gene called TP53—it’s referred to as the ‘guardian of the genome’. It is a tumor suppressor gene and prevents cancer of all types."

"Humans have two copies and if one is broken/mutated it causes an inherited condition called Li Fraumeni. People with this have a very, very high risk for cancer, and the condition can be passed down in families.

"Elephants have 20 copies of TP53 and therefore rarely get cancer. The Li Fraumeni foundation uses the elephant as its mascot and hopefully we can someday figure out how to replace faulty TP53 genes for these families."

~ OrangeMonarchQueen

Clones

"Since navel oranges have no seeds, they are all clones of the original mutated fruit discovered by a Brazilian monk a century ago."

"The billions and billions of navel oranges that have been grown, sold and consumed since are all genetically identical."

~ JK_NC

Biodiversity...

"Cheetahs are extremely inbred."

"They had a massive bottleneck about 10,000 years ago and had too little diversity to fully recover."

~ confusedbox03

...Or Rather Lack Thereof

"Similar thing happened to Tasmanian Devils. Genetically, they are so similar that the cancer that grows on their necks and faces is contagious."

"They scratch themselves and transmit the cancer cells to other devils during fights. The cancer does not have to do a lot of adjusting."

~ PomPomGrenade

"Basically they're so genetically similar, the usual markers bodies use to go 'Hey, those aren't my cells!' are just kinda like 'Eh, looks right to me...' instead."

"So if a cancer cell gets physically transferred from one Tasmanian Devil to another it can just keep growing."

~ ArcFurnace

Desirable Trait

"Some genetic diseases persist because having one copy of the disease causing version of a gene can have benefits, so even though having two copies is deadly, one copy of the gene doesn't go away in the population."

~ uxoriousHouseHusband

"It’s an example of why it doesn’t make sense to talk about the fittest example of any organism without specifying its environment."

"If you live in an environment with little or no malaria, being a carrier for sickle cell anemia or thalassemia makes you less fit. If you have children with another carrier, 1 in 4 of them will be very sick, and might even die. That’s bad."

"If, however, you live in an environment where malaria is a common problem, then you have resistance to a deadly disease, and half of your children will as well."

"It’s an adaptation to one environment that makes you less fit in a different environment. Who’s more fit? You can’t answer that question without taking the environment into account."

~ linuxgeekmama

CRISPR*

"The first CRISPR/Cas** treatment for sickle cell has just been approved by the FDA."

~ Specialist-Ad432

"I work in this field in a capacity that I get to talk to all the companies that are up and coming. There is a tsunami of mRNA-based gene editing treatments on the horizon."

"WAY, WAY more than anyone not plugged into the VC/stealth mode ecosystem suspects."

"We will look back on 2023 as the year that medicine changed forever."

~ kcidDMW

* CRISPR is a family of DNA sequences found in the genomes of prokaryotic organisms such as bacteria and archaea.

** CRISPR-Cas is an adaptive immune system existing in most bacteria and archaea, preventing them from being infected by phages, viruses and other foreign genetic material.

We're In The Shallow End...

"If you set aside ethics and set out to do it, it would only take 33 generations to create a human being who was the descendant of everyone currently alive and able to have children."

~ Triton1017

...Of The Gene Pool

"Pedigree collapse."

"No living person has as many unique ancestors as they mathematically should. Every person has, biologically, 2 parents, 4 grandparents, 8 great-grandparents, etc... doubling every generation.

"30 generations back without any degree of inbreeding would require over a billion unique 28x great grandparents, more than the entire world population during 1100 AD."

"Every single human's family tree is full of people marrying and having children with cousins of some genetically-unimportant degree over the last thousand years."

~ Triton1017

Chimera

"Genetic chimera is arguably the most interesting condition. It is possible (and documented) for a woman to give natural birth but the baby not match her DNA test."

"Essentially, 2 fertilized eggs merge at a very early stage and developing into a single organism. Different parts of the body comprised of obe or the other genome."

"It's most commonly discovered in domestic animals that have unexplainable color combinations, often (but not always) divided symmetrically."

~ Eagle_1776

Genetic Lottery

"For simplicity, let's say your mother is 50% Chinese (C) & 50% Spanish (S). That does not mean you are 25% of each."

"On paper it would seem so, but you can have any combination of those two equaling to 50%. It's not a clean cut in half."

"It's a random 50% given and 50% not. Although, yes there are dominant genes that can give all the kids a certain nose shape or eye color."

"Still, you and your siblings might get these DNA combos from mom:"

• "you: 30% C & 20% S"
• "brother: 12% C & 38% S"
• "sister: 5% C & 45% S"

"So if you ever wondered why your sister looks more Chinese than you, its because genetics wise she just is more Chinese."

~ a_person1852

Po-Ta-Toes

"Potatoes have more chromosomes than humans."

~ AccurateEnvironment4

"That makes sense, most potatoes I know have no humans!"

~ Downtown-Candle-5805

"That explains all the extra eyes."

~ UnsupervisedAsset

Paternity

"Twins can have different fathers."

~ Coded-influx

"Superfecundation. Very rare in humans, but not crazy rare."

"Supposedly in humans it's one in every 400 sets of fraternal twins or one in every 13,000 births on average."

~ Kyadagum_Dulgadee

"Very rare in humans, but not in cats."

~ imSOtiredzzz

Microscopic Aliens

"Amoebas have a bigger genome than humans—and by like a hundred times bigger."

~ Amazing-Row-5963

"How completely bizarre."

"Why do they need so many genes?"

"What are they plotting‽‽"

Are they aliens‽‽‽"

~ nangatan

Gesundheit

"There’s this thing called ACHOO [Autosomal Dominant Compelling Helioopthalmic Outburst] Syndrome where it’s estimated that 18-35% of people on Earth have a reflex that induces sneezing due to bright light."

~ HeyImGilly

Microchimerism

"When you’re pregnant, bits of DNA from your baby invade your body and settle all over permanently—including in your brain."

"Researches found this by looking for male DNA in the brains of deceased 70 year-old women who gave birth to males."

"Interestingly, mouse studies have also shown that fetal cells within the mother have restorative properties and will rush to places like the heart, kidneys, lungs, liver if it’s injured."

"One of the theories I have seen, but I don’t know if anyone knows for certain if this is true, is that these cells enter our bodies so a ‘host’ is less likely to reject the parasite baby."

~ Sweaty-Peanut1

"It's called microchimerism. As in, the mythical creature the chimera.

"Younger siblings can also receive cells from older siblings that transfered to and from the mother."

~ skippy94

So, did you learn anything new?

Is there a fact you know that didn't make the list?