Artificial Comet Key to Origin of Life
Artificial comet key to origin of life, according to articles in ScienceDaily 7 April 2016, Science Alerts 8 April 2016 and Science doi: 10.1126/science.aad8137. In order to explain the origin of life by natural processes many scientists have tried to make the chemicals that are essential for function of living things. One of these is a sugar named ribose. This is similar to another molecule named deoxyribose – better known as the D in DNA. Ribose is part of a molecule named RNA, which is just as essential to life as DNA as it carries the information stored on DNA to the rest of the cell.
According to current theories on the origin of life, the earth did not have the right conditions for forming ribose before life started, so some scientists have suggested it formed on comets in outer space. There is evidence the chemical precursors of ribose exist in outer space, so scientists at Institut d'Astrophysique Spatiale made an artificial comet using a mixture of water, methanol and ammonia, which they placed in a vacuum chamber at minus 200 degrees C to simulate the formation of cometary ice. They then exposed it to ultra-violet light and gradually warmed it to simulate a comet approaching the sun.
Another research team at Institut de Chimie de Nice analysed the chemicals in the warmed irradiated mix and found numerous organic molecules including ribose. The researchers commented that precursors of proteins and genetic material have been found in outer space and went on to say "if delivered from meteorites in the Earth's environment, their coevolution may be considered one of the standing issues in prebiotic chemistry".
The ScienceDaily article is entitled "Origin of life: An artificial comet holds the missing piece" and summarised the results as, "Their findings shed new light on the emergence of life on Earth".
Science Alerts, ScienceDaily
Editorial Comment: Take note of two very important 'left outs'.
Firstly, this piece of clever chemical manipulation and analysis is the latest in a long list of experiments claimed to show how life could evolve from non-living molecules, beginning with Miller's famous amino acid experiment. However, all they really prove is that intelligent organic chemists can design experiments that produce organic molecules. Ribose on its own is simply a molecule. Setting up a chemical environment that will produce it tells us nothing about how it came to be made and put to use in a living cell.
The second left out is indeed 'LEFT out'. Ribose, like many organic molecules comes in two different forms, called right and left handed. These are chemically the same, but slightly different in shape. In living cells the ribose is all right handed, but ribose made by natural random chemical processes is always a mixture of left and right handed molecules, and that is what these new experiments produced. Producing exclusively right or left handed organic molecules requires carefully planned and designed processes. Furthermore, when a pure solution of left or right handed molecules is made, it is not long before natural processes begin to degrade it into a mix of left and righted handed. Natural chemical processes always produced mixtures, and even one wrong handed molecule in the mix will ruin its function in a living cell.
Pure one-sided molecules require creative intelligence. This was confirmed in 2001 when the Nobel Prize in chemistry was awarded to scientists who developed methods for producing one-sided molecules. It never happens by itself – it always requires a creator.
Another issue being ignored altogether is the little problem that to make RNA, ribose has to be combined with two other molecules, a phosphate and a base, to make a component called a nucleotide. There are four different nucleotides in RNA, named A, U, G and C, depending which base was added to the ribose and phosphate.
This brings us to the most significant difference between the molecules in a living cell and those made in a laboratory, or in outer space. It is how they are organised and work together. RNA consists of a string of nucleotides. The function of a particular RNA molecule is determined by the sequence, i.e. the arrangement, of nucleotides forming the string. In a cell the RNA sequence is determined by pre-existing information on DNA. DNA information is also determined by the sequence of its component parts, not by the chemical bonds that hold them together. Information does not come from chemistry – it comes from the mind of someone who knows the properties of chemicals and uses them to store and transfer information. Therefore, even if there is ribose, amino acids and other molecules in comets, they won't make life without a creative intelligence to assemble them in the right way. Actually forgive our sarcasm. This last point about getting all this to have information is not a little issue at all – it's a killer point for all theories of naturalistic origin so don't miss it! (Ref. abiogenesis, chemical evolution, sugars)
Evidence News, vol. 16, No. 7