New Study Reveals Most of Our DNA is Junk
At least three quarters of the human genome consists of non-functional, ‘junk DNA‘, according to a new study, and the actual proportion is likely to be even greater than that.
Ever since Watson and Crick discovered the double helix structure of DNA back in the 1950s, scientists have been debating what extent of the genome is responsible for making you you – and now an evolutionary biologist says the answer to the riddle lies in some basic math.
Dan Graur from the University of Houston calculates that the functional portion of the human genome probably constitutes only about 10 to 15 percent of our overall DNA, with an upper limit of 25 percent.
The rest of our genome – somewhere between around 75 to 90 percent of our DNA – is what’s called junk DNA: not necessarily harmful or toxic genetic matter, but useless, garbled nucleotide sequences that aren’t functional in terms of encoding proteins that spur all the important chemical reactions going off inside our bodies.
The rationale for Graur’s model is based on the way mutations creep into DNA, and how as a species we weed these mutations out for the benefit of all.
These kinds of genetic variants, called deleterious mutations, appear in our genome over time, subtly shifting or reordering the four chemical bases that make up DNA – adenine, cytosine, guanine and thymine – in parts of our genetic code.
When mutations take place in junk DNA, they’re considered neutral – since that genetic code doesn’t do anything, anyway – but when mutations occur to our functional, defining DNA, they can often be harmful and even ultimately lethal, as they mess up the instructions that code for healthy tissue and biological processes.
On that basis, it’s better for our evolutionary prospects if less of our DNA is functional, because less of it is then exposed to the risk of mutation and the increased chances of early death it invites.
In Graur’s calculations, given the risk of deleterious mutations to the survival of the species on one hand – and the known stability of population and reproduction rates throughout human history on the other – the limit of functional DNA has to be very low.
Otherwise dangerous mutations would keep stacking up, meaning we’d have to produce impossibly huge numbers of offspring for the small percentage of healthy bubs to survive.
“Under the assumption of 100 percent functionality and the range of deleterious mutation rates used in this paper, maintaining a constant population size would necessitate that each couple on average produce a minimum of 24 and a maximum of 5 × 1053 children,” he writes in his paper.
Of course, nobody really other than creationists is suggesting that we carry around zero junk DNA, but a huge 2012 study called the Encyclopaedia of DNA Elements (ENCODE) project did claim that as much as 80 percent of human DNA was functional.
That study was controversial – partly because many scientists claimed that the ENCODE definition of ‘functional’ was too broad.
In Graur’s use of the term – where functional DNA is code that’s evolved to be useful in terms of its evolutionary effects – the 80 percent figure just doesn’t add up.
“For 80 percent of the human genome to be functional, each couple in the world would have to beget on average 15 children and all but two would have to die or fail to reproduce,” he writes.
It’s more likely then that only about 10 to 25 percent isn’t junk DNA, Graur thinks.
While his is unlikely to be the last word on the subject – the new results do coincide somewhat neatly with the findings of a separate 2014 study – and could help focus vital scientific efforts on researching a smaller window of uncontested, ‘functional’ DNA.
“We need to know the functional fraction of the human genome in order to focus biomedical research on the parts that can be used to prevent and cure disease,” Graur says.
“There is no need to sequence everything under the sun. We need only to sequence the sections we know are functional.”
The findings are reported in Genome Biology and Evolution.
Read more at www.sciencealert.com
PRINCIPIA SCIENTIFIC INTERNATIONAL, legally registered in the UK as a company 
incorporated for charitable purposes. Head Office: 27 Old Gloucester Street, London WC1N 3AX.
Please DONATE TODAY To Help Our Non-Profit Mission To Defend The Scientific Method.
Trackback from your site.
Joseph Olson
| #
This is part of the SELF LOATHING narrative programming that is consistent theme in the feral government funding of the full range of faux science. PSI post is not in support of this human JUNK hypothesis, but only for easy reference on my future pandemic debunking.
There is a readily apparent, alternate reality once the mosaic pieces are rearranged correctly.
Reply
TL Winslow
| #
Are you against the “junk” hypothesis, or merely the use of the name junk? A large lobby wants to use the term non-functional, which doesn’t change the fact that there are no known functions for them.
You don’t think Susumu Ohno was right in finding an upper limit of 30K on the number of functional loci that can be expected for a given mutation rate in mammals to avoid an excessive mutational load leading to a decline in fitness and extinction?
https://en.wikipedia.org/wiki/Susumu_Ohno
https://en.wikipedia.org/wiki/Junk_DNA
What does this have to do with feral govt., faux science, or pandemic debunking?
http://www.historyscoper.com/geneticistscope.html
Did God make Adam and Eve perfect so that their DNA never developed a mutation and every piece of DNA had a function? If so, what about after they were expelled from Eden and eventually died of old age? 🙂 What color were they, and how did races arise from a single human pair without some DNA mutations? 🙂
http://www.historyscoper.com/whiteracescope.html
Reply
Charles Higley
| #
In recent decades, junk DNA has been increasingly recognized as having regulatory roles in metabolism. There are hordes of small interactive RNA and proteins as and, particularly, RNA-protein complexes that may serve feedback mechanisms on the functional genes. snRNPs and scRNPs (small nuclear ribonucleic-proteins and small cytoplasmic ribonucleic-proteins).
Reply
Herb Rose
| #
This is another crap study comparable to those which explained why bumble bees can’t fly.
Mutation is rare and almost always detrimental (there thousands of wrong solutions, few right). The fact that they reduce viability makes the contention that they are stored in DNA through generations ridiculous.
The DNA that is active changes as we develop with different portions active and dormant at different stages of development. They are like blueprints where different instructions become applicable as development progresses. Just because a gene may not be active does not mean it is junk and was not necessary in producing the end result.
Reply
tom0masom
| #
So Dan Graur, you don’t know what all the non-functional DNA is, so you call it junk. MORONS!
DNA acts as a messaging system to get new cells made. As such the DNA sequences falls within not only biology but communication systems. And in communication there comes information theory.
https://en.wikipedia.org/wiki/Information_theory
Maybe this ‘junk DNA’ is the error correcting code to ensure correct replication?
Error identification and correction is an everyday method to ensure that messages are transmitted from one place to another with the minimum of corruption. It is used in just about all forms of modern digital communications systems. When applying error correction methods the actual size of the data sent is larger but the salient message parts are made more robust because they can, by many different numerical methods, be checked to ensure that they are not corrupted by the transmission environment.
To do this the actual transmitted message (say the functional parts of the DNA) are interleaved with check messages that ensure that corruptions are identified and maybe even corrected. And even then the overall message could have a final ‘envelope’ of error correction applied to ensure that the whole DNA message has maintained its overall integrity.
Thus in the DNA structure these so called ‘junk DNA’ may actually be the error identification and correction codes required to ensure correct replication without corruption.
The thing with DNA is to understand that the message is not in binary (like computer code) but is encoded by means of complex set of simple monomeric units called nucleotides ( https://en.wikipedia.org/wiki/DNA ). With each nucleotide composed of one of four nitrogen-containing nucleobases (cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and a phosphate group.
IMO, Dan Graur needs a wider education and far more experience of the world to realize that nature is NOT inefficient and does NOT fill DNA with junk!
Reply
Joel Walbert
| #
Sounds like another non-condition that some deadly drug or toxic vaccine will be developed for
Reply