There is absolutely no reason to believe that only functional DNA is transcribed into RNA. There is every reason to believe that leaky RNA transcriptase activity and non-specific transcription factor binding will result in the transcription of junk DNA. The null hypothesis is that an RNA molecule has no function. In order to claim that an RNA molecule has function you need evidence that it is functional. It’s mere existence is not evidence for function.[quote=“SamuraiChamploo, post:1, topic:36081”]
And what do they mean by “function” anyway? No one ever really defines it clearly!
Depends on who you talk to. The definition used by ENCODE was “changes the biochemistry of the cell”. By that definition, the trash in your kitchen trash can has function because it changes the biochemistry of the air in your kitchen. IOW, ENCODE used a definition of function that included junk DNA. Most people define function as a stretch of DNA that has sequence specific activity which impacts the fitness of the organism. This type of function is often detected by sequence conservation, although not all functional DNA can be detected by this method.[quote=“SamuraiChamploo, post:1, topic:36081”]
Anyone want to attempt responses at the three points written by Dr. Rana?
Skimming through the article, it appears that Dr. Rana uses the same bad argument that many other ID/creationists use. They play the definition game. For example, they will point out that junk DNA is non-coding DNA. They will then find some non-coding DNA that has function, and claim that there is no junk DNA. They use the Association Fallacy:
All A’s are B
B, Therefore A.
We can find other examples of this fallacy, such as “All Chevy Malibu’s are cars. My brother bought a car, therefore it must be a Malibu.” What the ID/creationists fail to understand is that no one is saying that all non-coding DNA is junk DNA. Junk DNA is just a subset of all non-coding DNA just as Chevy Malibu’s are a subset of all cars.
They also use a generalization fallacy. If they can find a 100 base pair stretch of DNA that was once thought to be junk but is now thought to have function, they will claim that this one example means that the other 2.5 billion bases of junk DNA must also have function. That’s nonsense.
However, the most basic error the make is thinking that evolution predicts junk DNA. It doesn’t. No one is saying that evolution is true because there is junk DNA. For example, the bladderwort genome is almost entirely functional, yet no one is claiming that it falsifies evolution. Evolution allows for genomes to have a lot of junk or very little junk. The only thing that junk DNA seems to clash with is the ID/creationist claim that God made genomes with 100% functionality.
If there are specific points of the article that you have questions on fee free to ask.