Junk DNA

[anon]

@anon

Ok, dammit, I’m switching sides.

@Nick Lane

In his celebrated book Chance and Necessity, the committed atheist and Nobel Prize-winning molecular biologist Jacques Monod tackled the theme of purpose. Plainly, he said, it is pointless to discuss the heart without mentioning that it is a pump, whose function is to pump blood around the body. But that is to ascribe purpose. Worse, if we were to say that the heart evolved to pump blood, we would be committing the ultimate sin of teleology – the assignment of a forward-looking purpose, a predetermined end-point to an evolutionary trajectory. But the heart could hardly have evolved ‘for’ anything else; if it didn’t evolve to pump blood, then it is truly a miracle that it happened to become so fine a pump. Monod’s point was that biology is full of purpose and apparent trajectories, and it is perverse to pretend they don’t exist; rather, we must explain them. The question we must answer is this: how does the operation of blind chance, a random mechanism without foresight, bring about the exquisitely refined and purposeful biological machines that we see all around us?

source

Sure, anon, but let’s take this one step further…

@Ernst Mayr

“The Wood Thrush migrates in the fall in order to escape the inclemency of the weather and the food shortages of the northern climates.”

“The Wood Thrush migrates in the fall and thereby escapes the inclemency of the weather and the food shortages of the northern climates.”

If we replace the words ‘in order to escape’ by ‘and thereby escapes’, we leave the important question unanswered as to why the Wood Thrush migrates. The teleonomic form of the statement implies that the goal-directed migratory activity is governed by a program. By omitting this important message the second sentence is greatly impoverished as far as information content is concerned, without gaining in causal strength.

Mayr is most definitely mistaken in his assessment of the situation - he makes the mistake of turning the world as he understands it, into the world. His fear of impoverished science ironically prevents him from wanting to investigate the complexity of the real situation any further. This is an example of science as the search for solid ground, to the detriment of exploration and advancement.

Teleology in scientific explanations is a bad business.

[hooper]

My daughter’s doing her 4th year in Biology
and playing with genes.

One thing I hear is- only a few of the genes are
being expressed (proteins are being made from them).
The rest are tangled up like in a big knot and
not available for use. Like the other ninety-some percent.

But, even then, there are sequences where
there is just a sort sequence that repeats
hundreds of times. This is junk.

But there’s other junk; portions and even
entire genes of old viruses make up a large
percentage of our genome. Some peoples carry much
more of that than others, apparently!

Interesting stuff.

john

[marmite]

@hooper

My daughter’s doing her 4th year in Biology
and playing with genes.

One thing I hear is- only a few of the genes are
being expressed (proteins are being made from them).
The rest are tangled up like in a big knot and
not available for use. Like the other ninety-some percent.

But, even then, there are sequences where
there is just a sort sequence that repeats
hundreds of times. This is junk.

But there’s other junk; portions and even
entire genes of old viruses make up a large
percentage of our genome. Some peoples carry much
more of that than others, apparently!

Interesting stuff.

john

Was thinking this topic would be along those lines too, that only about 4% of your DNA is functioning and the rest is made up of ancient retroviruses, dead formally functioning DNA (such as the DNA that made your tail grow) and possible your dead twins ovaries as well as abit of Neanderthal (if your eurasian) a whole host of possible internal mutations capable of making you crazy or paralyzed at any moment. Your non-junk DNA is functioning now in the sense of a drunk trying to do a rubiks cube in the dark. Its not really purpose driven, there are mathmatical sequences found all over nature, common designs that function most effectly in this earth bound environment. Just like sand flowing downwards in a timer. Infact, i don’t even know what im trying to say here.

[Calrid]

@marmite

@hooper

My daughter’s doing her 4th year in Biology
and playing with genes.

One thing I hear is- only a few of the genes are
being expressed (proteins are being made from them).
The rest are tangled up like in a big knot and
not available for use. Like the other ninety-some percent.

But, even then, there are sequences where
there is just a sort sequence that repeats
hundreds of times. This is junk.

But there’s other junk; portions and even
entire genes of old viruses make up a large
percentage of our genome. Some peoples carry much
more of that than others, apparently!

Interesting stuff.

john

Was thinking this topic would be along those lines too, that only about 4% of your DNA is functioning and the rest is made up of ancient retroviruses, dead formally functioning DNA (such as the DNA that made your tail grow) and possible your dead twins ovaries as well as abit of Neanderthal (if your eurasian) a whole host of possible internal mutations capable of making you crazy or paralyzed at any moment. Your non-junk DNA is functioning now in the sense of a drunk trying to do a rubiks cube in the dark. Its not really purpose driven, there are mathmatical sequences found all over nature, common designs that function most effectly in this earth bound environment. Just like sand flowing downwards in a timer. Infact, i don’t even know what im trying to say here.

Read those links I gave previously. There is evidence that non coding DNA can act to preserve important sections of DNA that are coding. In that case they need not code to have a function. It exists because if it is lost, then certain important coding genes become less likely to survive, providing a less “fit” genome overall.