These meteorites contain all of the building blocks of DNA

These meteorites contain all of the building blocks of DNA

Nicoletta Lanese

Three meteorites contain the molecular building blocks of DNA and its cousin RNA, scientists recently discovered. A subset of these building blocks had been detected in meteorites before, but the rest of the collection seemed mysteriously absent from space rocks — until now.

The new discovery supports the idea that, some four billion years ago, a barrage of meteorites may have delivered the molecular ingredients needed to jump-start the emergence of the earliest life on Earth, the researchers say.

However, not everyone is convinced that all of the newfound DNA components are extraterrestrial in origin; rather, some may have ended up in the meteorites after the rocks touched down on Earth, said Michael Callahan, an analytical chemist, astrobiologist and associate professor at Boise State University who was not involved in the study. "Additional studies are needed" to rule out this possibility, Callahan told Live Science in an email.

These meteorites contain all of the building blocks of DNA

Nicoletta Lanese

I just say Ho Hum to yet another popular science pronouncement of getting closer to the solution to the origin of life problem. The reality is that even after 70 years of intense research biologists are hardly any closer to a nonteleological solution. The main reason is obviously that even the simplest living reproducing cell contains a super-complex system of systems of integrated intricate and irreducibly complex molecular machines all working in concert to maintain life and reproduce. The notion that this could have come about through a combination or series of accidents is absurd.

The building blocks of life in meteorites or asteroids idea is just another attempt to suggest that Nature by abiogenically making these amino acids and other compounds somehow was able to design and assemble the intricate machinery of life. As ridiculous as suggesting that a series of accidents could assemble a watch starting with a pile of the constituent parts like gears, nuts, bolts, springs, levers, and the like (of course of all possible sizes and exact shapes), or assemble even a simple computer by accident starting with a pile of transistors, diodes, memory elements, wires, etc.

I just say Ho Hum to yet another popular science pronouncement of getting closer to the solution to the origin of life problem. The reality is that even after 70 years of intense research biologists are hardly any closer to a nonteleological solution. The main reason is obviously that even the simplest living reproducing cell contains a super-complex system of systems of integrated intricate and irreducibly complex molecular machines all working in concert to maintain life and reproduce. The notion that this could have come about through a combination or series of accidents is absurd.

The building blocks of life in meteorites or asteroids idea is just another attempt to suggest that Nature by abiogenically making these amino acids and other compounds somehow was able to design and assemble the intricate machinery of life. As ridiculous as suggesting that a series of accidents could assemble a watch starting with a pile of the constituent parts like gears, nuts, bolts, springs, levers, and the like (of course of all possible sizes and exact shapes), or assemble even a simple computer by accident starting with a pile of transistors, diodes, memory elements, wires, etc.

Yes indeed! The crucial points are that:

1) Natural selection cannot plausibly operate before any life arrived on the earth.

2) Instructions encoded on DNA consist of long chains of symbols (nucleotides) which need to be just about perfect to be of any use. This implies that the relevant DNA evolves in stages, one mutation at a time. Since most of the intermediate steps confer no individual fitness to the organism, combinatorial calculations rule.

3) I'd love to read how StephenW escapes the above, without using a lot of undefined terms such as 'informational'.

Yes indeed! The crucial points are that:

1) Natural selection cannot plausibly operate before any life arrived on the earth.

2) Instructions encoded on DNA consist of long chains of symbols (nucleotides) which need to be just about perfect to be of any use. This implies that the relevant DNA evolves in stages, one mutation at a time. Since most of the intermediate steps confer no individual fitness to the organism, combinatorial calculations rule.

3) I'd love to read how StephenW escapes the above, without using a lot of undefined terms such as 'informational'.

Even preceding this, there is the matter of the origin of the DNA structure and coding scheme themselves.

@stephenw

Stephen,

I'd really like to pull you in here, and I think perhaps I have the perfect analogy to DNA that I hope will appeal to you.

Let's think of that meteorite as containing plastic letters that children use to learn to read - hundreds of thousands of them - and maybe some of them had even become stuck together into random strings.

Would you call the letters themselves, 'informational', or would you designate the random strings as 'informational'?

Now suppose you dug deep into the meteorite and found a treatise on cooking sponge cake. Would you feel that that was a sign of evolution, or maybe that the meteorite was artificial?

David

@stephenw

Stephen,

I'd really like to pull you in here, and I think perhaps I have the perfect analogy to DNA that I hope will appeal to you.

Let's think of that meteorite as containing plastic letters that children use to learn to read - hundreds of thousands of them - and maybe some of them had even become stuck together into random strings.

Would you call the letters themselves, 'informational', or would you designate the random strings as 'informational'?

Now suppose you dug deep into the meteorite and found a treatise on cooking sponge cake. Would you feel that that was a sign of evolution, or maybe that the meteorite was artificial?

David

The thought experiment is fun, but not practical for analysis.  The idea that "letters" are informational with structure and meaning, before they are imbedded in a functional communication system, is not practical.

The context of a circumstance without mind is the crucial concept.  It does not exist naturally, as life may be a possibility on all planets.  My own worldview would have mind there before representation begins, causing it.  The whole idea that chemicals are the basis of language is incredible to me.  Mind can detect probable functioning.  And will/intend a pattern of information that can lead to a representation in a bio-information process.

DNA/RNA\Ribosome systems are a product of mental woork.

The thought experiment is fun, but not practical for analysis.  The idea that "letters" are informational with structure and meaning, before they are imbedded in a functional communication system, is not practical.

Well are the DNA 'letters' any more informational (I'd still like a definition for that term - does it mean full of information, e.g. a book). In particular, there ar eonly four types - it is considerably more sparse than the English alphabet.

My own worldview would have mind there before representation begins, causing it. 

Well if you mean that mind of some sort preceded life on earth, I am with you - but I didn't think you were comfortable with the idea of a disembodied mind (soul?).

David

Well are the DNA 'letters' any more informational (I'd still like a definition for that term - does it mean full of information, e.g. a book). In particular, there are only four types - it is considerably more sparse than the English alphabet.

Well if you mean that mind of some sort preceded life on earth, I am with you - but I didn't think you were comfortable with the idea of a disembodied mind (soul?).

David

You seem to want to find a metaphysical essence in knowing what information is?

Shannon information is a method to quantify the amount of probability, differentiation, individual states, answers from yes/no questions and the amount of useful structure between systems (entropy). 

The study of language and of semiosis, along with logic is the basis of how we understand meanings and social behavior.

Why would you think I don't talk about character as an information object, built by decision-making.  Is character subsumed by soul?  I think that makes sense in being able to be useful in ethics.

Personally, soul as the developed human character, works for me.

As to 4 "letters" being an issue; binary digits seem to able to express almost anything.

As to 4 "letters" being an issue; binary digits seem to able to express almost anything.

Yes they do, but you seemed to want to make a distinction between my alphabet example and the DNA alphabet.

David

Yes they do, but you seemed to want to make a distinction between my alphabet example and the DNA alphabet.

David

DNA "alphabet"?  Help me with what you mean.

The bio-code includes more than DNA information.