The First Information Age: The Origin of DNA – Part I

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If you are reading this right now you are riding on the train of what some call “The Information Age”.  The internet, cell phones, computers, etc. were all made in the burst of technological advancements made in the very recent past – but information itself is much older.  In fact, information is as old as life itself.  Many argue that the biomolecule most essential to life is DNA.  DNA actually encodes information through its chemical sequence, and can then transmit that information.  Hence, the arrival of DNA on early Earth constitutes the first “Information Age” – the first time when a system could not only carry information, but use that information to perform a function.  How did such a molecule, with its intricate structure and specific sequences necessary to store information, arise on early Earth through undirected natural processes?  This is the topic of this series of posts.

Function is also a word we are all familiar with.  The car that you drive is said to “function” when you go out to your garage, put the key in the ignition, and the car starts.  Our bodies are well-oiled machines that again are described as functioning, with each component pulling its weight through performing its own specific function contributing to the machine as a whole.  In the origin of life, one thing which is of paramount importance is how there was selection from a bath of varying degrees of complexity of molecules, some of which may resemble the necessary biomolecules for life (DNA, RNA, or proteins), for the even more complex, very specific biomolecules that compose life as we know it.  Function is one of the necessary components in separating “life” from “non-life”.  It is also essential in order for natural selection to act – you must have a certain degree of functional diversity, i.e. enough different things which exhibit functions, some of which may be advantageous in the environment provided.   Both evolutionists and its critics question whether chance encounters alone are not enough to explain the origin of function, which will primarily be the topic of Part I of this series of posts.  DNA (or what is thought to be its predecessor – RNA, differing only by the sugar used in its chemical make-up) is commonly used as the key example, since it is essential to life through its information bearing properties. 

There are essentially two routes to the production of certain specific molecules on early Earth: chance or necessity (an idea first proposed by Aleksandr Oparin in terms of molecules in the origin of life, but is essentially just an extension of Darwin’s original ideas).  The first, chance, is essentially what it sounds like: complex molecules arose literally through random, chance interactions, with no external driving forces.  Many have taken this mechanism and have subsequently calculated the probability of a complex biomolecule having arisen on early Earth.  One such calculation is presented in Stephen C. Meyer’s 2009 book “Signature in the Cell”.  It is important to note that Meyer is an intelligent design proponent, but, as I will present later, calculations such as these are performed by both evolutionists and its skeptics.  And yes, as a little disclaimer, I do read both intelligent design literature as well as evolutionary literature – I am a firm believer in being fully educated from the primary sources on all sides of a debate.  Anyways, back to the issue at hand, in his book Meyer presents a few different calculations (using varying assumptions) of the odds of producing any functioning 150-amino acid long protein sequence from chance alone.  All of these calculations result in a final number of 1 in 10164 – a number which, to most people, is unfathomable.  To put this number in perspective, Meyer compares it to the chance of finding a marked proton in the universe (1 in 1080) or to the number of events since the beginning of the universe (10140)…so in conclusion, it is literally impossible (according to Meyer and his numbers at least) to form even one functional 150-amino acid long protein from chance alone.

As I asserted earlier, the improbability of chance alone is also acknowledged by evolutionists.  Take one of the most celebrated figures in popular science circles concerning Evolution: Richard Dawkins.  In his book, “The Blind Watchmaker”, he also shows that chance alone is unlikely to have been able to account for the complexity of life seen today.  He uses the now celebrated example of the assembling of the phrase “METHINKS IT IS LIKE A WEASEL” from Hamlet using a random combination of letters and spaces.  Using simple statistics, the probability of getting the first letter in the sequence, “M”, is 1 in 27.  The entire phrase is 28 characters long, therefore, the probability of randomly receiving the entire sequence is (1/27)28 (1/27 multiplied by itself 28 times) which results in “about 1 in 10,000 million million million million million million” (Dawkins, 1996).  These odds admittedly are very small, resulting in the probability of getting the exact phrase from Hamlet through “single-step selection of random variation” (i.e. chance) as asserted by Dawkins being highly unlikely.  So, Dawkins comes to the same conclusion as Meyer – getting even a simple phrase from Hamlet, much less a complex, information-bearing biomolecule such as DNA, is very improbable with chance alone.  Therefore, we must move on to Oparin’s other option: necessity.

As you can imagine, most scientists have given up on chance alone being enough for the origin of life on Earth – not to say they have turned to supernatural sources.  Rather, they now search to find environments in which the chemical reactions necessary to form these molecules are more favorable.   Although chance will always comprise a portion of the physical and chemical processes leading up to the production of a biomolecule such as DNA in the origin of life, these processes can be driven by environmental factors as well – resulting in the influence of necessity.  If the environment favors one reaction over another, then that reaction will be enhanced, resulting in the production of certain products over the distribution of products which would result from chance alone.  Hence, the environment is skewing the odds for a particular reaction.  This sounds great in theory, but is there any evidence that this could be the case?  Is there scientific research being done in this area, or is it merely stated to overcome the challenges posited by the existence of such a complex, essential molecule as DNA?  This will be explored further in my next post – in fact, this is currently an area of intense interest to origin of life scientists, and there are those attempting to tackle it (including Dawkins himself – could you imagine him leaving the issue as stated above??).

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One thought on “The First Information Age: The Origin of DNA – Part I

  1. Pingback: The First Information Age: The Origin of DNA – Part 2 | OriginsSkeptic

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