Creationists here and elsewhere like to cite the ENCODE study as scientific evidence that around 80% of the human genome has function. Have any of those creationists actually read the paper, or understand the data and how it relates to the conclusions? In my experience, their understanding of the science starts and stops at the three characters, "8", "0", and "%". They hope by repeating this mantra that it will produce an air of competence to their posts.
So how does ENCODE define "functional". Loosely, if you are being generous. I did find a wonderful blog posts written by one of the head scientists for ENCODE, and he all but admitted that about 70% of the DNA they call functional is functional in the same way that the dust bunnies under your couch are functional.
"However, on the other end of the scale – using very strict, classical definitions of “functional” like bound motifs and DNaseI footprints; places where we are very confident that there is a specific DNA/protein contact, such as a transcription factor binding site to the actual bases – we see a cumulative occupation of 8% of the genome. With the exons (which most people would always classify as “functional” by intuition) that number goes up to 9%."
http://genomeinformatician.blogspot.co.uk/2012/09/encode-my-own-thoughts.html
So about 10% of the genome is really functional. The other 70%? Well, it does stuff, like being made into RNA at really low levels. Does that RNA actually do something? They didn't look. Rather, simply "changing the biochemistry" of the cell is enough to be classified as "functional" at ENCODE, just like being a dust bunny changes the mass distribution in your living room.
Another good analogy that another scientist uses is an immortal television set that keeps functioning no matter what damage or changes you make to it. Why? Because it keeps attracting dust from the air, which can be defined as a function.
"From an evolutionary viewpoint, a function can be assigned to a DNA sequence if and only if it is possible to destroy it. All functional entities in the universe can be rendered nonfunctional by the ravages of time, entropy, mutation, and what have you. Unless a genomic functionality is actively protected by selection, it will accumulate deleterious mutations and will cease to be functional. The absurd alternative, which unfortunately was adopted by ENCODE, is to assume that no deleterious mutations can ever occur in the regions they have deemed to be functional. Such an assumption is akin to claiming that a television set left on and unattended will still be in working condition after a million years because no natural events, such as rust, erosion, static electricity, and earthquakes can affect it."
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3622293/
So instead of being told that there is way more junk DNA now than what we thought 10 years ago, I would rather like to see examples of this 80% of the genome actually doing something that impacts phenotype and fitness. Any examples?
So how does ENCODE define "functional". Loosely, if you are being generous. I did find a wonderful blog posts written by one of the head scientists for ENCODE, and he all but admitted that about 70% of the DNA they call functional is functional in the same way that the dust bunnies under your couch are functional.
"However, on the other end of the scale – using very strict, classical definitions of “functional” like bound motifs and DNaseI footprints; places where we are very confident that there is a specific DNA/protein contact, such as a transcription factor binding site to the actual bases – we see a cumulative occupation of 8% of the genome. With the exons (which most people would always classify as “functional” by intuition) that number goes up to 9%."
http://genomeinformatician.blogspot.co.uk/2012/09/encode-my-own-thoughts.html
So about 10% of the genome is really functional. The other 70%? Well, it does stuff, like being made into RNA at really low levels. Does that RNA actually do something? They didn't look. Rather, simply "changing the biochemistry" of the cell is enough to be classified as "functional" at ENCODE, just like being a dust bunny changes the mass distribution in your living room.
Another good analogy that another scientist uses is an immortal television set that keeps functioning no matter what damage or changes you make to it. Why? Because it keeps attracting dust from the air, which can be defined as a function.
"From an evolutionary viewpoint, a function can be assigned to a DNA sequence if and only if it is possible to destroy it. All functional entities in the universe can be rendered nonfunctional by the ravages of time, entropy, mutation, and what have you. Unless a genomic functionality is actively protected by selection, it will accumulate deleterious mutations and will cease to be functional. The absurd alternative, which unfortunately was adopted by ENCODE, is to assume that no deleterious mutations can ever occur in the regions they have deemed to be functional. Such an assumption is akin to claiming that a television set left on and unattended will still be in working condition after a million years because no natural events, such as rust, erosion, static electricity, and earthquakes can affect it."
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3622293/
So instead of being told that there is way more junk DNA now than what we thought 10 years ago, I would rather like to see examples of this 80% of the genome actually doing something that impacts phenotype and fitness. Any examples?
Last edited:
![[serious]](/data/avatars/m/160/160873.jpg?1431539545){kind=avatar}
