Theoretical origin of life; an optimistic history of researc (Introduction)

by David Turell @, Friday, November 04, 2016, 14:42 (2701 days ago) @ David Turell

This is can extremely long accurate history of the research in origin of life. It is optimistically cast as if 'they' are getting close. No way! What doesn't work is well understood. what dos cerate life is not understood:

http://www.bbc.com/earth/story/20161026-the-secret-of-how-life-on-earth-began

"The strength of Miller-Urey is to show that you can go from a simple atmosphere and produce lots of biological molecules," says John Sutherland of the Laboratory of Molecular Biology in Cambridge, UK.

"The details turned out to be wrong, since later studies showed that the early Earth's atmosphere had a different mix of gases. But that is almost beside the point.

***

"Writing in Nature in 1986, Gilbert proposed that life began in the "RNA World".
The first stage of evolution, Gilbert argued, consisted of "RNA molecules performing the catalytic activities necessary to assemble themselves from a nucleotide soup".

***

"An alternative approach has been put forward by Gerald Joyce and Tracey Lincoln of the Scripps Research Institute in La Jolla, California. In 2009 they created an RNA enzyme that replicates itself indirectly.

"Their enzyme joins together two short pieces of RNA to create a second enzyme. This then joins together another two RNA pieces to recreate the original enzyme.

"This simple cycle could be continued indefinitely, given the raw materials. But the enzymes only worked if they were given the correct RNA strands, which Joyce and Lincoln had to make. ( my bold)

***

"But no self-replicating RNA had been found, and nobody could figure out how RNA formed in the primordial soup. The alternative nucleic acids might solve the latter problem, but there was no evidence they ever existed in nature. That was less good.
The obvious conclusion was that the RNA World, neat as it was, could not be the whole truth.

***

"Once life had harnessed the chemical energy of the vent water, Russell and Martin say, it started making molecules like RNA. Eventually it created its own membrane and became a true cell, and escaped from the porous rock into the open water.

"This story is now regarded as one of the leading hypotheses for the origin of life.

***

"So Sutherland has set out to find a "Goldilocks chemistry": one that is not so messy that it becomes useless, but also not so simple that it is limited in what it can do. Get the mixture just complicated enough and all the components of life might form at once, then come together.

"In other words, four billion years ago there was a pond on the Earth. It sat there for years until the mix of chemicals was just right. Then, perhaps within minutes,
the first cell came into existence.

***

"There might even be room for the alternatives to RNA that have been cooked up in labs, like the TNA and PNA we met in Chapter Three. We do not know if any of them ever existed on Earth, but if they did the first organisms may well have used them alongside RNA.

"This was not an RNA World: it was a "Hodge-Podge World".

"The lesson from these studies is that making the first cell might not have been as hard as it once seemed. Yes, cells are intricate machines. But it turns out that they still work, albeit not quite as well, when they are flung together slapdash from whatever is to hand.

***

"In nature, many enzymes have a metal atom at their core. This is often the "active" part of the enzyme, with the rest of the molecule essentially a support structure. The first life cannot have had these complex enzymes, so instead it probably used "naked" metals as catalysts.

***

"Some of the people alive today will become the first in history who can honestly say they know where they came from. They will know what their ultimate ancestor was like and where it lived."

Comment: the optimistic last paragraph is not consistent with the accurate history given. The enzymes needed have not been found, and no on knows what natural enzymes were available 3.8 billion years ago. My bolds indicate all this research is intelligent design in labs. Very long article. I've only touched the surface.


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